*15141 mm-1050 >> Im trying to find a series where the sum of a subset of that >> is unique. Or in other words, I can find the numbers from sum. >> >> An example would be f(n)=2^n, you add any number of elements >> in this set, youll get a number with all those bits set. >> But Im looking for a series that does not grow geometrically.. >I was looking for a series which consists of positive integers >which has this property. > This has already been answered. Since the 2^n series is the Ômost efficient > such series, all other series must grow faster. Not true. See below. >Is it helpful if the size of the subset is known? >For example, the sum of random 10 elements of a series is given, >is it possible to get the individual elements(I mean is there >such a series of positive integers other that 2^n and doesnt >grow exponentially)? > I believe this doesnt really change the outcome. All size-10 subsets must > produce a unique sum implies (with handwave) that all subsets must produce a > unique sum, so your sequence is going to grow exponentially. I dont think I believe this. Its anyway not true that if all size-2 subsets produce a unique sum then all subsets produce a unique sum, and its not clear to me why size-10 should differ from size-2 in this regard. Theres a lot of literature on these problems. A good starting place is Guys Unsolved Problems in Number Theory. The 3rd edition is out, but I dont have it yet. In the 2nd edition, C9 concerns m, the maximum number of integers between 1 and n inclusive with all sums of pairs distinct. The conjecture is that m - sqrt n is bounded. C11 concerns the requirement that sums of h terms all be distinct for some given h. C8 asks about the maximum number of positive integers not exceeding 2^k with all subset sums distinct. Conway & Guy conjecture its k + 2 - notice that this is better than the k + 1 you get by taking powers of 2. An example that achieves k + 2 is given. C5 says you can reconstruct a set of N numbers from the set of sums of pairs provided N is not a power of 2. Sums of size 3 determine the set except perhaps when N = 27 or 486. Sums of larger size have also been considered. -- Gerry Myerson (gerry@maths.mq.edi.ai) (i -> u for email) === Subject: Re: Finding unique sums. > C8 asks about the maximum number of positive integers not exceeding > 2^k with all subset sums distinct. Conway & Guy conjecture its > k + 2 - notice that this is better than the k + 1 you get by taking > powers of 2. An example that achieves k + 2 is given. I too was convinced that you couldnt do better than powers of 2, and Id be very interested to see that example. For those of us who dont have the book, is the example simple enough for you to reproduce here? (Im not asking you to type in ten pages of text!) === Subject: Re: Finding unique sums. > C8 asks about the maximum number of positive integers not exceeding > 2^k with all subset sums distinct. Conway & Guy conjecture its > k + 2 - notice that this is better than the k + 1 you get by taking > powers of 2. An example that achieves k + 2 is given. I too was convinced that you couldnt do better than powers of 2, and > Id be very interested to see that example. For those of us who dont > have the book, is the example simple enough for you to reproduce here? > (Im not asking you to type in ten pages of text!) Here are some reviews from Math Reviews, you can probably extract the information you want (and more!) from them, especially if TeX doesnt bother you. MR0917837 (89a:11019) Lunnon, W. F.(4-WALC) Integer sets with distinct subset-sums. Math. Comp. 50 (1988), no. 181, 297--320. 11B13 (94A60) The set of integers $p_i=2^{i-1}$, $i=1,2,cdots,n$, has the interesting property that all of its distinct subsets have distinct sums. Let us call this property SSD. The question is whether there are sets $overline{p}={p_0=01)$. It is easy to see that the polynomial $g_m(x)=prod_{k=1}^m(1+z^{J_k})$ has the above-defined properties and that $$deg g_m=frac43.872^m-frac32+frac{(-1)^m}6.$$ Therefore, $$d(m)lefrac43.872^m-frac32+frac{(-1)^m}6.$$ The authors show that the equality holds if and only if $mle5$. In the general case, they prove that $$2^m+c_1mle d(m)le frac{103}{96}.872^m+c_2$$ and they conjecture that for any $epsilon>0$ the inequality $d(m)<(1+epsilon)2^m$ holds for sufficiently large $m$. Also, they consider the related problem of finding a set of $m$ positive integers with distinct subset sums and minimal largest element and show that the well-known Conway--Guy sequence yields the optimal solution for $mle9$. Reviewed by Sergeui V. Konyagin MR1486396 (98k:11014) Bohman, Tom(1-MIT) A construction for sets of integers with distinct subset sums. (English. English summary) Electron. J. Combin. 5 (1998), Research Paper 3, 14 pp. (electronic). 11B75 (05D10) A finite set $S$ of positive integers has distinct subset sums if the $2sp{|S|}$ sums $sumsb{ain A}a$, where $Asubseteq S$, are pairwise distinct. For brevity, call sets with distinct subset sums DSS-sets. The paper investigates the following questions: How small can a positive integer $N$ be such that ${1,2,cdots,N}$ contains an $n$-element DSS-set? For every $n$ let $f(n)$ be the smallest $N$ with this property. In different terms: $f(n) = min max_S N$, where the minimum is taken over all $n$-element DSS-sets. Obviously, $f(n)le 2sp {n-1}$ (take $S={1,2,4,cdots,2sp{n-1}})$. Erd.9as conjectured that $f(n)gg 2sp n$ (the implicit constant is absolute). Together with Moser he proved in 1955 a weaker inequality $f(n)ge 2sp n /(4sqrt n)$, which remains, up to the constant, the best known lower bound for $f(n)$. In the opposite direction, J. H. Conway and R. K. Guy ref[Notices Amer. Math. Soc. 15 (1968), no. 2, 345, Abstract 654-32] constructed short DSS-sets, using a special sequence of integers they discovered (the Conway-Guy sequence). Their result implied an estimate $f(n) le 0.23513.872sp n$ for $nge 40$. W. F. Lunnon ref[Math. Comp. 50 (1988), no. 181, 297--320; MR0917837 (89a:11019)] suggested a similar construction, which implied $f(n) le 0.22096 .872sp n$ for $nge 67$. In his paper Bohman presents two parametric families of infinite sequences, which include, for small values of parameters, the sequences of Conway-Guy and Lunnon. Using his sequences, he finds many new examples of DSS-sets, and, in particular, obtains a new upper estimate $f(n) le 0.22002 .872sp n$ for sufficiently large $n$. Bohmans construction is very subtle and interesting and is likely to find different applications in combinatorics, cryptography, and related fields. Reviewed by Yuri Bilu MR1464377 (98i:11012) Maltby, Roy(3-CALG) Bigger and better subset-sum-distinct sets. (English. English summary) Mathematika 44 (1997), no. 1, 56--60. 11B75 A set of natural numbers is called subset-sum-distinct (SSD) if all pairwise distinct subsets have unequal sums. If $A$ is any SSD set, define $alpha(A)=(max A)/2^{|A|-1}$, where $max A$ is the biggest element of $A$. Given an SSD set, it is shown how to construct a bigger SSD set whose $alpha$-ratio is smaller. This shows that $inf{alpha(A)colon A$ is an SSD set}is not realised by any SSD set. (Erd.9as asked if the inf is positive.) The author also points out that one of the claims of W. F. Lunnon ref[Math. Comp. 50 (1988), no. 181, 297--320; MR0917837 (89a:11019)] concerning SSD sets is false. Reviewed by Ian Anderson MR1363448 (97b:11027) Bohman, Tom(1-RTG) A sum packing problem of Erd.9as and the Conway-Guy sequence. (English. English summary) Proc. Amer. Math. Soc. 124 (1996), no. 12, 3627--3636. 11B75 A set $A$ of positive integers has distinct subset sums if the set ${sum_{xin X}xcolon Xsubseteq A}$ has $2^{|A|}$ distinct elements. J. H. Conway and R. K. Guy ref[Notices Amer. Math. Soc. 15 (1968), 345] defined a sequence, ${A_k}$, of sets of integers as follows: (1) let $u_0=0, u_1=1$, and, for $ngeq1, u_{n+1}=2u_n-u_{n-r}$, where $r$ is the closest integer to $sqrt{2n}$; (2) for each $kgeq1$, define $A_k={u(k+1)-u(i)colon1leq ileq k}$. They conjectured that for every $k, A_k$ has distinct subset sums, and they showed this to be true for $1leq kleq40$. W. F. Lunnon ref[Math. Comp. 50 (1988), no. 181, 297--320; MR0917837 (89a:11019)] extended this to all $kleq80$. In this paper the author establishes the conjecture of Conway and Guy for all $k$. Define $f(n)=min{max_{sin S}scolon|S|=n$ and $S$ has distinct subset sums}. The Conway-Guy sequence mentioned above gives rise to $2^{n-2}$ as an upper bound on $f(n)$. This bound was improved by Lunnon to $0.2246(2^n)$. In this paper, the author presents a modification of the Conway-Guy sequence, and states that this leads to a slight improvement over Lunnons bound, namely $0.22002(2^n)$. The author does not include a proof of this statement here, but plans to include it in a later paper. Reviewed by Bruce Landman -- Gerry Myerson (gerry@maths.mq.edi.ai) (i -> u for email) === Subject: Re: Finding unique sums. matt a .8ecrit : >> C8 asks about the maximum number of positive integers not exceeding >> 2^k with all subset sums distinct. Conway & Guy conjecture its >> k + 2 - notice that this is better than the k + 1 you get by taking >> powers of 2. An example that achieves k + 2 is given. > I too was convinced that you couldnt do better than powers of 2, and > Id be very interested to see that example. For those of us who dont > have the book, is the example simple enough for you to reproduce here? > (Im not asking you to type in ten pages of text!) Cest un forum en fran.8dais, respectez la charte ! -- Denis L.8eger === Subject: Re: Finding unique sums. > matt a .8ecrit : >> C8 asks about the maximum number of positive integers not exceeding >> 2^k with all subset sums distinct. Conway & Guy conjecture its >> k + 2 - notice that this is better than the k + 1 you get by taking >> powers of 2. An example that achieves k + 2 is given. I too was convinced that you couldnt do better than powers of 2, and > Id be very interested to see that example. For those of us who dont > have the book, is the example simple enough for you to reproduce here? > (Im not asking you to type in ten pages of text!) > Cest un forum en fran.8dais, respectez la charte ! Please accept my apologies. I didnt notice that this was being posted to a French-language group. === Subject: Re: Finding unique sums. > Cest un forum en fran.8dais, respectez la charte ! > Please accept my apologies. I didnt notice that this was being posted > to a French-language group. Dont worry Matt, some of us enjoy a little international ßavour on the French group :-) The bullies wont have their ways... === Subject: Re: Finding unique sums. Vous avez aussi poste ce message a des forums anglais, donc vous navez pas respecte leurs chartes. -ilan > matt a .8ecrit : >> C8 asks about the maximum number of positive integers not exceeding >> 2^k with all subset sums distinct. Conway & Guy conjecture its >> k + 2 - notice that this is better than the k + 1 you get by taking >> powers of 2. An example that achieves k + 2 is given. I too was convinced that you couldnt do better than powers of 2, and > Id be very interested to see that example. For those of us who dont > have the book, is the example simple enough for you to reproduce here? > (Im not asking you to type in ten pages of text!) > Cest un forum en fran.8dais, respectez la charte ! === Subject: Re: Finding unique sums. > How about the sequence > 0.4142135623730950488016887242... > 0.8284271247461900976033774484... > 0.6568542494923801952067548968... > 0.3137084989847603904135097936... > 0.6274169979695207808270195873... > 0.2548339959390415616540391747... > 0.5096679918780831233080783494... > .... > (Puzzle - is the sequence dense in [0,1]? (The sequence is 2^(n + 1/2) mod > 1).) Puzzle, or open problem? Think of the sequence as the fractional part of 2^n sqrt2, and youll see it depends on the binary expansion of sqrt2. I dont think enough is known about the binary expansion of sqrt2 to answer the question. -- Gerry Myerson (gerry@maths.mq.edi.ai) (i -> u for email) === Subject: Re: Finding unique sums. >> How about the sequence >> 0.4142135623730950488016887242... >> 0.8284271247461900976033774484... >> 0.6568542494923801952067548968... >> 0.3137084989847603904135097936... >> 0.6274169979695207808270195873... >> 0.2548339959390415616540391747... >> 0.5096679918780831233080783494... >> .... >> (Puzzle - is the sequence dense in [0,1]? (The sequence is 2^(n + 1/2) mod >> 1).) >Puzzle, or open problem? >Think of the sequence as the fractional part of 2^n sqrt2, and youll >see it depends on the binary expansion of sqrt2. I dont think enough >is known about the binary expansion of sqrt2 to answer the question. Its equivalent to the question of whether every finite string of 0s and 1s occurs in the binary expansion of sqrt(2). This is indeed open (although I would bet that the answer is yes). Robert Israel israel@math.ubc.ca Department of Mathematics http://www.math.ubc.ca/~israel University of British Columbia Vancouver, BC, Canada === Subject: Re: Finding unique sums. > How about the sequence > 0.4142135623730950488016887242... > 0.8284271247461900976033774484... > 0.6568542494923801952067548968... > 0.3137084989847603904135097936... > 0.6274169979695207808270195873... > 0.2548339959390415616540391747... > 0.5096679918780831233080783494... > .... > (Puzzle - is the sequence dense in [0,1]? (The sequence is 2^(n + 1/2) mod > 1).) > Puzzle, or open problem? > Think of the sequence as the fractional part of 2^n sqrt2, and youll > see it depends on the binary expansion of sqrt2. I dont think enough > is known about the binary expansion of sqrt2 to answer the question. Well I dont know the answer myself, so I suppose I should have said open problem... > -- > Gerry Myerson (gerry@maths.mq.edi.ai) (i -> u for email) === Subject: Courants Introduction to Calculus and Analysis I solutions to exercises Im reading the R.Courant/F.John book Introduction to Calculus and Analysis I as a primer on real analysis. The preface (written in 1965) alludes to a solutions pamphlet for the problem sets, but I have not been able to locate any solutions. As Im using this for self-study, the solutions would be nice to have to check against. Does anyone have any information as to how I could obtain solutions to these problem sets? Michael === Subject: Re: Courants Introduction to Calculus and Analysis I solutions to exercises > Im reading the R.Courant/F.John book Introduction to Calculus and > Analysis I as a primer on real analysis. The preface (written in > 1965) alludes to a solutions pamphlet for the problem sets, but I have > not been able to locate any solutions. As Im using this for > self-study, the solutions would be nice to have to check against. > Does anyone have any information as to how I could obtain solutions to > these problem sets? > Michael Most often, solutions manuals are only available to faculty. David Ames === Subject: Re: Courants Introduction to Calculus and Analysis I solutions to exercises posting-account=jcZk7AwAAADXpPEyHtVyWC264SxtppRB I was speaking as a faculty member (and receiver of free trial books, esp. from Freeman--do they still do that?). Have you seen one for this book? I never did, and I taught a math physics course. Van === Subject: Re: Courants Introduction to Calculus and Analysis I solutions to exercises posting-account=jcZk7AwAAADXpPEyHtVyWC264SxtppRB I have this book, and have never seen a soln. book. Certainly not on the net. As I recall, most his stuff is examples worked out in the text. Van === Subject: Re: When a genius commits murder (Hawking & Witten composite on Law & Order CI) > When a genius commits murder, how do you outsmart him? 9/8pm Sunday, > November 21st > http://www.nbc.com/Law_&_Order:_Criminal_Intent/index.html > I just happened to catch this. Its a composite of Ed Witten and Stephen > Hawking as a murderer - motive to cover up the failure of his theory. > The actor is in Hawkings wheelchair with two wives - the one accused of > abusing him as in the recent Cambridge ßap (shes innocent in the TV > show) - I actually sat next to her and Hawking at GR 17 in Dublin in the > hotel as she was feeding him. The theory is more like Ed Wittens i.e. > 11 dimensions and the guy is an American not a Brit in the TV story. > Bizarre. I didnt see it, but let me guess: in addition to being an expert on art, music, wine, diamonds, and just about everything else (except how to shave), that guy on L&O:CI turns out to know a lot about physics. Am I right? -E === Subject: Re: When a genius commits murder (Hawking & Witten composite on Law & Order CI) > When a genius commits murder, how do you outsmart him? 9/8pm Sunday, > November 21st > http://www.nbc.com/Law_&_Order:_Criminal_Intent/index.html > I just happened to catch this. Its a composite of Ed Witten and Stephen > Hawking as a murderer - motive to cover up the failure of his theory. Of course the true answer is that if a genius in physics commits murder you outsmart him in any number of ways, because he wont be a genius at how to commit murder. Its like the old joke about how to beat Bobby Fisher. Answer: play him at anything but chess. SBH === Subject: Re: When a genius commits murder (Hawking & Witten composite on Law & Order CI) >When a genius commits murder, how do you outsmart him? 9/8pm Sunday, >November 21st >http://www.nbc.com/Law_&_Order:_Criminal_Intent/index.html >I just happened to catch this. I watched the show. I decided that the hidden agenda was to denigrate smart and productive people. The agenda wasnt all that hidden because the actor was madeup to look like Hawking. But the idiots couldnt get anything right...this actor was able to talk through his mouth. /BAH Subtract a hundred and four for e-mail. === Subject: Elementary probability of the infinite for the overworked mathematicians posting-account=Qiuj5AwAAACmGnmS12qcvqA9IXzD0s4L You are one person tossing a coin. I have infinite people, for every time you toss a coin, my infinite people all toss a coin aswell. A subset of my people have all got the same sequence as you, I never run out of people (infinite), you can toss your coin as long as you want, you NEVER form a new sequence to what an infinite set of people can make. Whatever sequence you form must be a *possible outcome* of tossing coins, infinite trials at the possible always succeed. With finite people, the length of the sequence where every combination is covered is finite, about log(#P). With infinite people, the length of the sequence where every combination is covered is without bound, INFINITE. Infinite length sequences are all covered, the diagonal is a Ôcheat and in standard theory it does not provide any new information to the dataset. Herc === Subject: Re: Deep Thoughts # 17: Liar Paradox is a Formal Metamathematical Theorem >>You _really_ need to work on the irony detector. Truth >>and provability are _different_ things - when you define >>one to be the other you exhibit amazing ignorance of the >>most basic issues. >>************************ >>David C. Ullrich >>We call a formula F(v1,. . .,vn) correct if for every n-tuple (a1,. . >>.,an), the sentence F(a1,. . .,an) is true. We let N be the >>first-order system whose axioms are all the correct formulas (this >>includes all logically valid formulas.) Thus, the provable formulas >>of N are nothing more than the axioms of N. >>Recursion Theory for Metamathematics - Raymond M. Smullyan, 1993 > hes not defining provability to be the > same as truth. (Hes setting up a _specific_ formal system in > which the two coincide. Theres a big difference.) That doesnt make any sense. How can you define provability (or anything else) without being in a system? Smullyan is setting up a specific formal system and youre not? So what are you talking about if its not a formal system? How does that work? > ************************ > David C. Ullrich === Subject: Re: Deep Thoughts # 17: Liar Paradox is a Formal Metamathematical Theorem >> >You _really_ need to work on the irony detector. Truth >and provability are _different_ things - when you define >one to be the other you exhibit amazing ignorance of the >most basic issues. ************************ David C. Ullrich >We call a formula F(v1,. . .,vn) correct if for every n-tuple (a1,. . >.,an), the sentence F(a1,. . .,an) is true. We let N be the >first-order system whose axioms are all the correct formulas (this >includes all logically valid formulas.) Thus, the provable formulas >of N are nothing more than the axioms of N. Recursion Theory for Metamathematics - Raymond M. Smullyan, 1993 >> hes not defining provability to be the same as truth. (Hes setting >> up a _specific_ formal system in which the two coincide. Theres a >> big difference.) > That doesnt make any sense. It does. Really. Given a language: * Truth (defined in the model theory) is a semantic relation that holds between a sentence of the language and an interpretation of the language. * Provability (defined in the proof theory) is a syntactic relation that holds between a set of sentences in the language and a given sentence of the language. It *follows* trivially from the definitions of N, truth, and provability that N |- A iff A is true in the standard model of the language of arithmetic iff A is an axiom of N. Thats a simple theorem. It isnt a definition of truth or provability. Makes good sense. HTH. === Subject: Re: what are the correct set theory axioms? at 04:55 PM, jasontesh@yahoo.com (Jason Tesh) said: >I checked out a SOL book thinking it would cover SO set theory, but I >couldnt find a statement of the axioms of SO set theory anywhere in >the book, so now Im still wondering what are the correct set theory >axioms? There are none. Its like asking what is the correct way to cook a meal. There are several different set theories, e.g., GBN, ZFC, and several minor variations for the axioms of each. Some set theories are roughly equivalent to others, and some are more powerful than others. You use the one that best suits your purpose at the time. -- Shmuel (Seymour J.) Metz, SysProg and JOAT Unsolicited bulk E-mail subject to legal action. I reserve the right to publicly post or ridicule any abusive E-mail. Reply to domain Patriot dot net user shmuel+news to contact me. Do not === Subject: a aTo show that 0 aI need N, the set of natural numbers, positive integers, that is, and >a way to write a,b,c,n in N. Whats an accepted notation in ASCII for in N >and not in N? in N and not in N, respectively. >N = { 1, 2, 3, ...} >I tolerance everything and tolerate everyone. >I love: Dona, Jeff, Kim, Kimmie, Mom, Neelix, Tasha, and Teri, alphabetically. >I drive: A double-step Thunderbolt with 657% range. >I fight terrorism by: Using less gasoline. ************************ David C. Ullrich === Subject: Re: a>Whats an accepted notation in ASCII for in N >>and not in N? >in N and not in N, respectively. Really? Theres no little sideways e or member of set notation? Darn. Ok, I like words. Well use words. For a,b,c,n in N, the set of natural numbers {1,2,3...} with a^n + b^n = c^n, we eliminate the trivial case a+b=c by adding 1 Do quartic polynomials exist which have all the following properties > (without regard to the size of their coefficients)? > A: They have rational zeroes (they split over Z, the ring of > integers), > B: Critical points have rational coordinates (their derivatives > split over Z), > C: Inßection points have rational coordinates (their second > derivatives split over Z), and > D: They have two distinct local minima (their derivatives have > three distinct zeroes), and the two points sharing a common > tangent line have rational coordinates. > My calculus students would have fun with these...easy to graph, and > to find the area of the region enclosed between the polynomial and > the tangent. > Cubics having properties A,B, and C are not hard to generate, but > attempts to integrate these and adjust the constant have not been > successful. Likewise, it is not hard to find quartics Q which split > over Z and have property D; but so far roots of Q or Q have come out > irrational. > I am sure Ramanujan would crack this peanut in a second... This is closely related to a well-studied problem, see --Bill Dubuque === Subject: Re: NUMBER THEORETIC POLYNOMIAL QUESTION ... > This is closely related to a well-studied problem, see of D(4) it gives: x^2(x-1)(x-a) with a = ((9(2w+z-12)(w+z))/((z-w-18)(8w+z)) and (w,z) in E(Q), E: z^2 = w(w-6)(w+18). Now setting w = 9 and z = -27, I find that point on E and a = -7/5. Now the second derivative is 12.x^2 + 12/5.x - 14/5, and the roots of that quadratic are not rational. The roots of the first derivative are rational. (z = +27 gives a zero denominator in the formula for a.) Setting w = -12 and z = -36, I find a = 432/77, and in that case the first derivative does not have rational roots. (On the other hand, when z = +36, a = 0, and it fits, as per the formula for D(n).) So either I am missing something, or the quoted formulas are wrong. I have no access to the original paper. -- dik t. winter, cwi, kruislaan 413, 1098 sj amsterdam, nederland, +31205924131 home: bovenover 215, 1025 jn amsterdam, nederland; http://www.cwi.nl/~dik/ === Subject: Re: How to determine f(x), given f(x)*f(-x) = -exp(kx^2) ? >> Hi all, >> How to determine f(x), given f(x)*f(-x) = -exp(kx^2) ? where x is a >> complex variable. >> Is there a method that I could use? >> Nischal >hi nischal, >the equation does not determine f uniquely. if f is assumed to even >(i.e. f(x)=f(-x)), then f(x)=i exp(kx^2/2) is a solution. >so, if no other condition is imposed on f, there seems to be a variety >of solutions for f. >/j. > A way to generalize is just adding any odd function g(x) so: > f(x)=i exp(kx^2/2 + g(x)) > Alain. Or, if one assumes that F is an odd function except at x = 0, then f(x) = sign(x) sqrt(e^(k x^2/2)), gives a solution except at x = 0 === Subject: Is this question fair for statistics class? i got -20 from a test http://www.johncho.us/stat.jpg , because i put zero correlation instead of curvilinear correlation, we did not study curvilinear correlations and such. I think it is unfair to put it on the test. Nearly every student got it wrong. Furthermore, every year that she has put it on the test students have gotten it wrong; that just tells me that she is not telling students the truth about things and rather going around the truth hoping that students find it. she said she drops the lowest test, but it does not say that on her syllbus i cannot believe she did this === Subject: Re: Is this question fair for statistics class? > i got -20 from a test http://www.johncho.us/stat.jpg , because i put zero > correlation instead of curvilinear correlation, we did not study > curvilinear correlations and such. > I think it is unfair to put it on the test. Nearly every student got it > wrong. > Furthermore, every year that she has put it on the test students have > gotten it wrong; that just tells me that she is not telling students the > truth about things and rather going around the truth hoping that students > find it. > she said she drops the lowest test, but it does not say that on her syllbus > i cannot believe she did this Although it may seem harsh, I do not think it was necessarily unfair. The question did not ask, Is there a correlation? The question asked, Is there a relationship? Your plot provided a plausible conclusion that there was a relationship, but clearly it wasnt a linear one. In that case, the correlation coefficient is not the right measure of association. Simply put, it was the wrong tool for the job as presented. An important part of statistics is the selection of the right tool for the job. Now, if the instructor did not spend class time on discussing when correlations are and are not appropriate measures of assocation you may have a beef; I wasnt in the class and so I dont know. But if the instructor did discuss that (and she certainly ought to have) then the question is actually a good one since it emphasizes the importance of intelligently looking at the data rather than mechanically applying formulas. -- Mark Thornquist === Subject: Bible Codes Resurrected? Equidistant Letter Sequences in the Book of Genesis which claimed to find evidence for hidden codes in the Hebrew text of Genesis. This number of debates in the scientific community as to whether the methodology was legitimate, then the implications would be that something supernatural is going on in the text of Genesis. And if not, debunked by a few enlightened scientists. evidence that the methodology of the experiment described in the 1994 1994 experiment was the fact that the experimenters did not use all possible Hebrew appellations of the names of the rabbis listed in the experiment and theoretically could have selected appellations which optimize the results of the experiment in favor of the claim that there are hidden codes in the Hebrew text of Genesis. In fact, the authors of the 1999 paper did just that by selecting different appellations of the names of the same rabbis, forcing a proof that there are hidden codes in the novel, War and Peace. And thus, the verdict from the scientific community was that the methodology in the 1994 experiment was ßawed and that there was no evidence for a hidden code phenomenon in Genesis. there were hidden codes in Genesis; it only showed that the original 1994 experiment methodology was ßawed. Furthermore, to their discredit, the journal Statistical Science did not allow the authors finding, discovered by Robert Haralick a professor of Computer Science at CUNY, can be described as follows: When all of the appellations experiment when performed on Genesis favors the codes phenomenon, and the result of the experiment when performed on War and Peace rejects a codes phenomenon. This finding is a major challenge to the authors of possible appellations been used in the experiment, no codes phenomenon would have been detected in Genesis. In other words, even though the methodology of the 1994 experiment, their War and Peace counterexample would now be rendered irrelevant, assuming that Haralicks findings are technically correct. You can download Haralicks paper here http://www.torahcodes.net as well as other papers in the section marked new. Note that I am not claiming that Haralicks findings are correct, but only that his claims should be taken seriously. I am interested to hear how the anti-codes crowd would intelligently dispute this finding. Also, I recommend anyone who is skeptical about the general codes phenomenon and knows some basic Hebrew to go here: http://www.meru.org/Lettermaps/B%27rePole.html Then combine the picture on that site with the explanation: When the aleph-beis is counted in base 3 starting at zero, we get the following relationships: (beis,yud)=(001,100), (vav,taf)=(012,210), (heh,mem)=(011,110), (lamed,reish)=(1,0,2)=(2,0,1). Notice that every letter in the picture (except for the first and last) horizontally pairs with itself or its mirror image. Whether or not you think that this is all a coincidence, youll have to agree that there is a very interesting pattern in the first verse of Genesis. Craig === Subject: Re: Bible Codes Resurrected? After thinking about Haralicks paper I have a few more comments to make. The objectivity of the data used by Witztum et al (1994) has been seriously criticized for the reasons I specified in a previous post to this thread. If Haralick wanted to avoid the critcism that his data is biased, he should not be including this data in his experiment at all. In fact, Haralick had many choices about where he derived his data from: 1. The first list of rabbis, dates, and appellations found in Witztum et al (1994) [1]. 2. The second list of rabbis, dates, and appellations in Witztum et al (1994) [1]. 3. The list created by specialist Simcha Emanuel using the rabbis from Witztum et als first list but his own judgement for the dates and appellations [1]. 4. The list created by Emanuel using a new list of rabbis given by McKay et al (1999) but still using his own judgement for the dates and appellations [1]. 5. The list created by Emanuel using the rabbis from Witztum et als second list, but the rules and styles of the appellations and dates from Witztum et als first list [1]. 6. The War and Peace list of rabbis and dates found by Bar-Natan et al (1999) [2]. This does not include the numerous other lists created from the rabbis cities experiment and its replications. Clearly Haralick had many choices when selecting which lists to use. He could have used one or more of any of the above lists, or he could have created his own list. Lists 1 and 2 have been severely criticized, and list 3, 5, and 6 are probably questionable. List 4 or a new list created properly would have been the two ideal lists to use. Yet we find that Haralick is using list 2 and 3 (both of which have been severely critcized) combined with list 6. Why would Haralick use a list 1 and 2 as part of his data? Perhaps because he realizes he has no chance of achieving remarkable results unless he uses list 1 or 2. Further, even if Haralick insists on using lists 1 and 2, why did Haralick choose 6 as his third list? This seems quite arbitrary, as Haralick could have used any of the four other lists or a new list. This certainly leaves much wiggle room as Barry Simon calls it. This only addresses some of the problems with the data. There may be similar problems with the improved protocol. For example, why did Haralick develop an improved protocol rather than the protocol recommended to Witztum et al by Diaconis, or the protocol actually used in Witztum et al? This again leaves wiggle room. > finding, discovered by Robert Haralick a professor of Computer Science > at CUNY, can be described as follows: When all of the appellations > experiment when performed on Genesis favors the codes phenomenon, and > the result of the experiment when performed on War and Peace rejects a > codes phenomenon. This finding is a major challenge to the authors of > possible appellations been used in the experiment, no codes phenomenon > would have been detected in Genesis. In other words, even though the > methodology of the 1994 experiment, their War and Peace counterexample > would now be rendered irrelevant, assuming that Haralicks findings > are technically correct. [1] http://cs.anu.edu.au/~bdm/dilugim/StatSci/data.html [2] http://cs.anu.edu.au/~bdm/dilugim/WNP/ === Subject: Re: Bible Codes Resurrected? > After thinking about Haralicks paper I have a few more comments to > make. > The objectivity of the data used by Witztum et al (1994) has been > seriously criticized for the reasons I specified in a previous post to > this thread. If Haralick wanted to avoid the critcism that his data is > biased, he should not be including this data in his experiment at all. > In fact, Haralick had many choices about where he derived his data > from: > 1. The first list of rabbis, dates, and appellations found in Witztum > et al (1994) [1]. > 2. The second list of rabbis, dates, and appellations in Witztum et al > (1994) [1]. > 3. The list created by specialist Simcha Emanuel using the rabbis from > Witztum et als first list but his own judgement for the dates and > appellations [1]. > 4. The list created by Emanuel using a new list of rabbis given by > McKay et al (1999) but still using his own judgement for the dates and > appellations [1]. > 5. The list created by Emanuel using the rabbis from Witztum et als > second list, but the rules and styles of the appellations and dates > from Witztum et als first list [1]. > 6. The War and Peace list of rabbis and dates found by Bar-Natan et al > (1999) [2]. > This does not include the numerous other lists created from the rabbis > cities experiment and its replications. > Clearly Haralick had many choices when selecting which lists to use. > He could have used one or more of any of the above lists, or he could > have created his own list. Lists 1 and 2 have been severely > criticized, and list 3, 5, and 6 are probably questionable. List 4 or > a new list created properly would have been the two ideal lists to > use. > Yet we find that Haralick is using list 2 and 3 (both of which have > been severely critcized) combined with list 6. Why would Haralick use > a list 1 and 2 as part of his data? Perhaps because he realizes he has > no chance of achieving remarkable results unless he uses list 1 or 2. Or more likely he didnt have access to those lists, as he said in his paper that he knew of no other publicly released lists. Remember that McKay did not release these lists in his published paper, only on his website. I think it is asking a little to much to expect Haralick, who is a busy man, to have to surf the net in order to find out about this information. Furthermore, what if Haralick were to have performed his analysis with these lists and the experiment were successful? Then McKay could have easily taken the lists down from his website and then people might accuse Haralick of tuning his lists. It sounds like you are moving the goalposts. In any case, if these other lists are reasonable, then there is no reason why Haralick should fear using them. But to accuse him of not having used them because he knows that they wont work is completely unfounded. > Further, even if Haralick insists on using lists 1 and 2, why did > Haralick choose 6 as his third list? This seems quite arbitrary, as > Haralick could have used any of the four other lists or a new list. > This certainly leaves much wiggle room as Barry Simon calls it. See above. > This only addresses some of the problems with the data. There may be > similar problems with the improved protocol. For example, why did > Haralick develop an improved protocol rather than the protocol > recommended to Witztum et al by Diaconis, or the protocol actually > used in Witztum et al? This again leaves wiggle room. protocal. The new protocal addresses these problems and is more descriptive of the Torah Code hypothesis. And if you read carefully wiggle room involved with the selection of the new metric. Craig === Subject: Re: Bible Codes Resurrected? > After thinking about Haralicks paper I have a few more comments to > make. The objectivity of the data used by Witztum et al (1994) has been > seriously criticized for the reasons I specified in a previous post to > this thread. > If Haralick wanted to avoid the critcism that his data is > biased, he should not be including this data in his experiment at all. > In fact, Haralick had many choices about where he derived his data > from: 1. The first list of rabbis, dates, and appellations found in Witztum > et al (1994) [1]. > 2. The second list of rabbis, dates, and appellations in Witztum et al > (1994) [1]. > 3. The list created by specialist Simcha Emanuel using the rabbis from > Witztum et als first list but his own judgement for the dates and > appellations [1]. > 4. The list created by Emanuel using a new list of rabbis given by > McKay et al (1999) but still using his own judgement for the dates and > appellations [1]. > 5. The list created by Emanuel using the rabbis from Witztum et als > second list, but the rules and styles of the appellations and dates > from Witztum et als first list [1]. > 6. The War and Peace list of rabbis and dates found by Bar-Natan et al > (1999) [2]. This does not include the numerous other lists created from the rabbis > cities experiment and its replications. Clearly Haralick had many choices when selecting which lists to use. > He could have used one or more of any of the above lists, or he could > have created his own list. Lists 1 and 2 have been severely > criticized, and list 3, 5, and 6 are probably questionable. List 4 or > a new list created properly would have been the two ideal lists to > use. Yet we find that Haralick is using list 2 and 3 (both of which have > been severely critcized) combined with list 6. Why would Haralick use > a list 1 and 2 as part of his data? Perhaps because he realizes he has > no chance of achieving remarkable results unless he uses list 1 or 2. > Or more likely he didnt have access to those lists, as he said in his > paper that he knew of no other publicly released lists. Remember that > McKay did not release these lists in his published paper, only on his > website. I think it is asking a little to much to expect Haralick, who > is a busy man, to have to surf the net in order to find out about this > information. Furthermore, what if Haralick were to have performed his > analysis with these lists and the experiment were successful? Then > McKay could have easily taken the lists down from his website and then > people might accuse Haralick of tuning his lists. > It sounds like you are moving the goalposts. In any case, if these > other lists are reasonable, then there is no reason why Haralick > should fear using them. But to accuse him of not having used them > because he knows that they wont work is completely unfounded. As a follow up, I notified Art Levitt, the author of the website that I pointed to, of your objection. He contacted Haralick and it appears that Haralick indeed was unaware of the other lists that you mentioned. He said, I will take a look to see if there are any additional web site. Craig === Subject: Re: Bible Codes Resurrected? > Clearly Haralick had many choices when selecting which lists to use. > He could have used one or more of any of the above lists, or he could > have created his own list. Lists 1 and 2 have been severely > criticized, and list 3, 5, and 6 are probably questionable. List 4 or > a new list created properly would have been the two ideal lists to > use. > Yet we find that Haralick is using list 2 and 3 (both of which have > been severely critcized) combined with list 6. Why would Haralick use > a list 1 and 2 as part of his data? Perhaps because he realizes he has > no chance of achieving remarkable results unless he uses list 1 or 2. Or more likely he didnt have access to those lists, as he said in his > paper that he knew of no other publicly released lists. Remember that > McKay did not release these lists in his published paper, only on his > website. I think it is asking a little to much to expect Haralick, who > is a busy man, to have to surf the net in order to find out about this > information. Furthermore, what if Haralick were to have performed his > analysis with these lists and the experiment were successful? Then > McKay could have easily taken the lists down from his website > and then people might accuse Haralick of tuning his lists. It sounds like you are moving the goalposts. In any case, if these > other lists are reasonable, then there is no reason why Haralick > should fear using them. But to accuse him of not having used them > because he knows that they wont work is completely unfounded. > As a follow up, I notified Art Levitt, the author of the website that > I pointed to, of your objection. He contacted Haralick and it appears > that Haralick indeed was unaware of the other lists that you > mentioned. > He said, I will take a look to see if there are any additional > web site. This is a good example of the quality of information that gets around on this subject. Of course Haralick is aware of the other lists because they are described in my paper published in Statistical Science. He also http://cs.anu.edu.au/~bdm/dilugim/StatSci/emanuel_rep.html So what you report is nonsense. More interestingly, Haralick has even collected appellations himself that are not in the two lists he used. The idea that one can take a set of data which is the one whose objectivity is being tested (WRRs data), combine it with some more data that was openly cooked (War and Peace data), then suddenly have an objective list, is breathtaking. And thats only the start of the problems with this appallingly bad paper of Haralick. Brendan McKay. === Subject: Re: Bible Codes Resurrected? As a follow up, I notified Art Levitt, the author of the website that > I pointed to, of your objection. He contacted Haralick and it appears > that Haralick indeed was unaware of the other lists that you > mentioned. He said, I will take a look to see if there are any additional > web site. > This is a good example of the quality of information that gets around > on this subject. > Of course Haralick is aware of the other lists because they are > described in my paper published in Statistical Science. He also > http://cs.anu.edu.au/~bdm/dilugim/StatSci/emanuel_rep.html > So what you report is nonsense. I directly quoted an email that Haralick cced me. It appears to me that he only made a mistake by forgetting about those extra lists he already used. I wouldnt infer from this that he deliberately ignored these lists because he knew that they would produce bad results - after all, what purpose would that serve him, as it would only be a matter of time when you or someone else would try it out and disprove him. And maybe they produce good results? I too would like to see him perform the experiment with the lists on your website. > More interestingly, Haralick has even collected appellations himself > that are not in the two lists he used. ones? The idea that one can take a > set of data which is the one whose objectivity is being tested > (WRRs data), combine it with some more data that was openly > cooked (War and Peace data), then suddenly have an objective > list, is breathtaking. He never claimed that he had an objective list. However, the fact that the experiment with the combined lists worked on Genesis and not War and Peace is something that one would not expect if there were no codes effect in Genesis and is consistent with the Torah codes hypothesis. In fact, it kind of reminds me of the Biblical passage in Exodus, 7:10 And Moses and Aaron went in unto Pharaoh, and they did so, as the Lord had commanded; and Aaron cast down his rod before Pharaoh and before his servants, and it became a serpent. 7:11 Then Pharaoh also called for the wise men and the sorcerers; and they also, the magicians of Egypt, did in like manner with their secret arts. 7:12 For they cast down every man his rod, and they became serpents; but Aarons rod swallowed up their rods. - that is of course assuming that everything is as Haralick describes. > And thats only the start of the problems with this appallingly bad > paper of Haralick. What are some other problems? I appreciate the work that you have done the subjectivity of the lists. If there are ßaws in the Haralick Craig > Brendan McKay. === Subject: Re: Bible Codes Resurrected? > As a follow up, I notified Art Levitt, the author of the website that > I pointed to, of your objection. He contacted Haralick and it appears > that Haralick indeed was unaware of the other lists that you > mentioned. > He said, I will take a look to see if there are any additional > web site. This is a good example of the quality of information that gets around > on this subject. Of course Haralick is aware of the other lists because they are > described in my paper published in Statistical Science. He also > http://cs.anu.edu.au/~bdm/dilugim/StatSci/emanuel_rep.html > So what you report is nonsense. > I directly quoted an email that Haralick cced me. It appears to me > that he only made a mistake by forgetting about those extra lists > he already used. I wouldnt infer from this that he deliberately > ignored these lists because he knew that they would produce bad > results - after all, what purpose would that serve him, as it would > only be a matter of time when you or someone else would try it out and > disprove him. And maybe they produce good results? I too would like to > see him perform the experiment with the lists on your website. They will only provide a few extra appellations. Anyway, note that I was responding to a specific claim and did not say that Haralick should have used or not used any particular data. Rather, the whole idea of his experiment is broken. A little on this below. > More interestingly, Haralick has even collected appellations himself > that are not in the two lists he used. > ones? Other way around. Haralick knows lots of valid appellations that are not used in his experiment. These include appellations he has collected himself for his own (other) experiments. They also include many that everyone knows. For example, the original experiment used appellations of the form Rabbi Yakov, but not Rav Yakov. As you know, the latter is an extremely common expression; why is it not used? There are many more examples. Why is the much smaller and more irregular set of appellations that work in War and Peace the correct set of additional appellations? And why is it correct to only add appellations when (according to our hypothesis) a major problem with the original data was the selective inclusion of doubtful appellations? (There are even two that nobody ever found a single example of in the literature.) > And thats only the start of the problems with this appallingly bad > paper of Haralick. > What are some other problems? I appreciate the work that you have done > the subjectivity of the lists. If there are ßaws in the Haralick Ill summarise what Haralick did. There are two sets of data and a third constructed from them. D1: data used by WRR for Genesis D2: data used by BMMK (McKay & al.) for War and Peace D3. the union of D1 and D2 Note that D1 and D2 have a very large overlap. D1 works well in Genesis and very poorly in War and Peace. D2 works well in War and Peace and fairly poorly in Genesis The question is: how does D3 behave? Using the analysis method of WRR, D3 works worse in Genesis than D1 did, and worse in War and Peace than D2 did. Somehow or other, Haralick found a different method of analysis for which D3 works about the same or slightly better in Genesis than D1 did, whereas D3 still works worse in War and Peace than D2 did. (Actually he found 4 new methods of analysis, some of which behave this way and some of which do not.) Haralick claims this proves something. I think it only proves that wishful thinking is strong medicine. The fact is that the result is extremely sensitive to both the data and the method of analysis. Seemingly tiny changes (like adding or deleting a single word, or replacing a mathematical expression by another with the same properties) can make the result jump up or down dramatically. Factors of 10 or more are nothing. I know of tiny changes to the analysis method (far far more minor than the changes between WRR and Haralick) that make the result for D2 in War and Peace 100 times better than the result for D1 in Genesis. What does this prove? Nothing. What does it prove if Haralick can come up with a method showing some other behaviour? Nothing. Besides this, Haralick has not established a significance level for his results. How likely is it for his observations to occur by chance? He doesnt even ask the question. (I have reason to believe that they are not very unlikely.) And lets not get started on the errors in his new methods. Brendan. === Subject: Re: Bible Codes Resurrected? Then I suppose I was incorrect, but if this is Haralicks only justification for neglecting to use these lists then this certainly not look good for Haralick or his experiment. The McKay et al (1999) paper uses two pages (pp. 24-25) to describe their independent scientific experiments and then concludes with The data for the above three experiments can be found at McKays web site (1999b). > As a follow up, I notified Art Levitt, the author of the website that > I pointed to, of your objection. He contacted Haralick and it appears > that Haralick indeed was unaware of the other lists that you > mentioned. > He said, I will take a look to see if there are any additional > web site. > Craig === Subject: Re: Bible Codes Resurrected? > Yet we find that Haralick is using list 2 and 3 (both of which have > been severely critcized) combined with list 6. That should have been Yet we find that Haralick is using list 1 and 2 (both of which have been severely critcized) combined with list 6. === Subject: Re: Bible Codes Resurrected? I am aware that the Bible Code topic is a controversial subject and that as a result, there are people on both sides of the issue, pro and con, who hold very strong opinions that are based on emotions and not on reason. If you are one of those people, then I recommend not wasting your time responding to me as I will not answer. I only posted my original letter in order to inform the curious and/or to receive For example, I just read paper 3 here: http://www.torahcodes.net/papers.html. The paper is only four pages long and discusses a 29 letter ELS (equidistant letter sequence code) in the Torah found in equidistant letter sequence which translates into I will name you ÔDestruction. Cursed is bin Laden and revenge belongs to the Messiah. encoded in (at least) a 29-letter ELS which contains the name bin Laden being found in the Torah are 1 in 83,000. Since this particular the capabilities of the codes author far exceed those of human beings. The experiment which led to the odds 1 in 83,000 is described fully in described therein; I am curious as to other reactions. Craig === Subject: Re: Bible Codes Resurrected? > I am aware that the Bible Code topic is a controversial subject and > that as a result, there are people on both sides of the issue, pro and > con, who hold very strong opinions that are based on emotions and not > on reason. If you are one of those people, then I recommend not > wasting your time responding to me as I will not answer. I only posted > my original letter in order to inform the curious and/or to receive > For example, I just read paper 3 here: > http://www.torahcodes.net/papers.html. > The paper is only four pages long and discusses a 29 letter ELS > (equidistant letter sequence code) in the Torah found in equidistant > letter sequence which translates into > I will name you ÔDestruction. Cursed is bin Laden and revenge > belongs to the Messiah. The grammar of this phrase seems quite poor. I can hardly translate Hebrew, but I imagine the grammar is even worse before it is translated. Since you can translate Hebrew perhaps you can provide your opinion. The point is this: If God encoded phrases in the Torah, would we expect the grammar of the phrases to be this poor? > encoded in (at least) a 29-letter ELS which contains the name bin > Laden being found in the Torah are 1 in 83,000. Since this particular > the capabilities of the codes author far exceed those of human > beings. > The experiment which led to the odds 1 in 83,000 is described fully in > described therein; I am curious as to other reactions. Perhaps you were not looking hard enough. Unless I am misunderstanding the details of the experiment, I see at least one major ßaw that makes it completely worthless. I will begin by brießy summarizing the procedure the authors used, based on my understanding. 1. An ELS was found by a Art Levitt in advance in the Torah that they translate to Destruction I will named you, Cursed [is] bin Laden and revenge [belongs] to the Messiah. The authors consider this ELS to be intelligible. (Huh?) The authors decide to test the hypothesis that this ELS is more intelligible than would be expected by chance. 2. The authors generate numerous random phrases of 29 characters (the length of the bin Laden ELS) or more and find 13,430 of these ELSs in their 614,400 control texts. They also manually find 8 phrases that are somewhat intelligible in these control texts. They present these ELSs to many subjects with the bin Laden ELS mixed in. 3. They present these ELSs to many control subjects with the bin Laden ELS mixed in. The subjects tended to consider the bin Laden ELS intelligible considerably more often (compared to the randomly generated phrases -- not the manually found ones) than would be expected by chance. After some calculations they arrive at a probability of 1.2e-05. The problem with this experiment seems obvious to me. They are measuring the intelligibility of an ELS found by a motivated person in a book the person was motivated to find an intelligible ELS in. They attempt to accomplish this by using human subjects to compare it to randomly generated phrases of the same length. Is it really that improbable that people would find the intelligible ELS more intelligible than the randomly generated ones? > Craig === Subject: Re: Bible Codes Resurrected? > I am aware that the Bible Code topic is a controversial subject and > that as a result, there are people on both sides of the issue, pro and > con, who hold very strong opinions that are based on emotions and not > on reason. If you are one of those people, then I recommend not > wasting your time responding to me as I will not answer. I only posted > my original letter in order to inform the curious and/or to receive For example, I just read paper 3 here: > http://www.torahcodes.net/papers.html. > The paper is only four pages long and discusses a 29 letter ELS > (equidistant letter sequence code) in the Torah found in equidistant > letter sequence which translates into I will name you ÔDestruction. Cursed is bin Laden and revenge > belongs to the Messiah. > The grammar of this phrase seems quite poor. I can hardly translate > Hebrew, but I imagine the grammar is even worse before it is > translated. Since you can translate Hebrew perhaps you can provide > your opinion. I agree that the first sentence is a little strange. However, the grammar in Hebrew is reasonable. The fact that the first sentence is strange was reßected in their experimental protocal, as this sentence did not get the highest marks as an intelligent sentence in the group of non-control sentences. > The point is this: If God encoded phrases in the Torah, would we > expect the grammar of the phrases to be this poor? This is not the issue. The issue is what are the odds of sentence being encoded in (at least) a 29-letter ELS which contains the name bin Laden being found in the Torah. Leave the theological issues to the theologians. > encoded in (at least) a 29-letter ELS which contains the name bin > Laden being found in the Torah are 1 in 83,000. Since this particular > the capabilities of the codes author far exceed those of human > beings. The experiment which led to the odds 1 in 83,000 is described fully in > described therein; I am curious as to other reactions. > Perhaps you were not looking hard enough. Unless I am misunderstanding > the details of the experiment, I see at least one major ßaw that > makes it completely worthless. I will begin by brießy summarizing the > procedure the authors used, based on my understanding. > 1. An ELS was found by a Art Levitt in advance in the Torah that they > translate to Destruction I will named you, Cursed [is] bin Laden and > revenge [belongs] to the Messiah. The authors consider this ELS to be > intelligible. (Huh?) The authors decide to test the hypothesis that > this ELS is more intelligible than would be expected by chance. > 2. The authors generate numerous random phrases of 29 characters (the > length of the bin Laden ELS) or more and find 13,430 of these ELSs in > their 614,400 control texts. They also manually find 8 phrases that > are somewhat intelligible in these control texts. They present these > ELSs to many subjects with the bin Laden ELS mixed in. > 3. They present these ELSs to many control subjects with the bin > Laden ELS mixed in. The subjects tended to consider the bin Laden ELS > intelligible considerably more often (compared to the randomly > generated phrases -- not the manually found ones) than would be > expected by chance. After some calculations they arrive at a > probability of 1.2e-05. > The problem with this experiment seems obvious to me. They are > measuring the intelligibility of an ELS found by a motivated person in > a book the person was motivated to find an intelligible ELS in. They > attempt to accomplish this by using human subjects to compare it to > randomly generated phrases of the same length. Is it really that > improbable that people would find the intelligible ELS more > intelligible than the randomly generated ones? accomplish this by using human subjects to compare it to randomly generated phrases of the same length. is not at all descriptive of their experiment. Craig === Subject: Re: Bible Codes Resurrected? > The problem with this experiment seems obvious to me. They are > measuring the intelligibility of an ELS found by a motivated person in > a book the person was motivated to find an intelligible ELS in. They > attempt to accomplish this by using human subjects to compare it to > randomly generated phrases of the same length. Is it really that > improbable that people would find the intelligible ELS more > intelligible than the randomly generated ones? > accomplish this by using human subjects to compare it to randomly > generated phrases of the same length. is not at all descriptive of > their experiment. Why is it not descriptive? Which part of that statement (or my description in general) do you find to be incorrect? I do think the description in the paper supports that statement; for example: Our method of significance estimation for an ELS phrase string found in a particular text is to compare its intelligibility to that of a large set of competitors. We do so by means of a large set of human reviewers who are asked to classify each string as to whether it is intelligible or not. A string - from any of these [comparison] texts - is accepted for human review only if all of its words come from a lexicon of the language of interest [Hebrew]. To find ELS phrase strings in a comparison text, we exhaustively search all possible spacings of words, requiring only that they form a continuous ELS that includes the chosen anchor. Certainly I could be incorrect, but if you wish to argue this then please do point out my error. === Subject: Re: Bible Codes Resurrected? > The problem with this experiment seems obvious to me. They are > measuring the intelligibility of an ELS found by a motivated person in > a book the person was motivated to find an intelligible ELS in. They > attempt to accomplish this by using human subjects to compare it to > randomly generated phrases of the same length. Is it really that > improbable that people would find the intelligible ELS more > intelligible than the randomly generated ones? accomplish this by using human subjects to compare it to randomly > generated phrases of the same length. is not at all descriptive of > their experiment. > Why is it not descriptive? Which part of that statement (or my > description in general) do you find to be incorrect? I do think the > description in the paper supports that statement; for example: > Our method of significance estimation for an ELS phrase string found > in a particular text is to compare its intelligibility to that of a > large set of competitors. We do so by means of a large set of human > reviewers who are asked to classify each string as to whether it is > intelligible or not. > A string - from any of these [comparison] texts - is accepted for > human review only if all of its words come from a lexicon of the > language of interest [Hebrew]. > To find ELS phrase strings in a comparison text, we exhaustively > search all possible spacings of words, requiring only that they form a > continuous ELS that includes the chosen anchor. > Certainly I could be incorrect, but if you wish to argue this then > please do point out my error. The part that says randomly generated phrases is not correct. They are phrases in virtual texts with specific characteristics. === Subject: Re: Bible Codes Resurrected? > Equidistant Letter Sequences in the Book of Genesis which claimed to > find evidence for hidden codes in the Hebrew text of Genesis. This > number of debates in the scientific community as to whether the > methodology was legitimate, then the implications would be that > something supernatural is going on in the text of Genesis. And if not, > debunked by a few enlightened scientists. > evidence that the methodology of the experiment described in the 1994 > 1994 experiment was the fact that the experimenters did not use all > possible Hebrew appellations of the names of the rabbis listed in the > experiment and theoretically could have selected appellations which > optimize the results of the experiment in favor of the claim that > there are hidden codes in the Hebrew text of Genesis. It is true that the choice of appellations is regarded by McKay et al (1999) to be the most serious problem with the data [1]. However, nowhere in the paper is it argued that Witztum et al should have used have used all possible appellations. > In fact, the > authors of the 1999 paper did just that by selecting different > appellations of the names of the same rabbis, forcing a proof that > there are hidden codes in the novel, War and Peace. This is certainly not the only evidence McKay et al (1999) found to support their argument that Witztum et al (1994) is ßawed. Aside from the demonstration by McKay et al that the phenomenon can be replicated in War and Peace, below is a brief summary of the evidence presented in McKay et al (1999) and in subsequent papers: 1. Witztum et al tended to choose options more favorable to their results when a choice was available [1]. The same was found in numerous other experiments by Witztum et al [2], and the bias is most apparent in the 70 nations experiment [3]. 2. The P2 value, a measurement used by Witztum et al., was closer to each other for the two lists of rabbis than what would be expected by chance. Having them close together makes it appear that the results are consistent. However, McKay et al. found that when shufßing the two lists of rabbis together and splitting them in half, the results were only equal around 1% of the time. The same study was performed on the rabbis in Gans cities experiment and found similar results [1]. 3. The several independent studies conducted by qualified mathematicians using data directly from encyclopedias and from independent experts have found no trace of the codes [1][4][5][6]. > And thus, the > verdict from the scientific community was that the methodology in the > 1994 experiment was ßawed and that there was no evidence for a hidden > code phenomenon in Genesis. > there were hidden codes in Genesis; it only showed that the original > 1994 experiment methodology was ßawed. Is there any evidence that could potentially be found that would refute the *possibility* that there are hidden codes in Genesis? What about hidden codes War and Peace? > Furthermore, to their > discredit, the journal Statistical Science did not allow the authors In fact, the editors of Statistical Science did invite Rips to submit a reply to McKay et als paper. However, the editors did not agree to allow Rips to bypass the peer-review process and have his reply published regardless of its quality [7]. This is nothing new. Witztum and others have posted numerous rebuttals since McKay et al (1999) was published [8][9], and McKay has replied to many of them [1][2]. Unfortunately it seems that many of the researchers who have spent countless hours in the past 10 years finding ßaw after ßaw in Torah Codes experiments are becoming tired of the subject [11]. > The major > finding, discovered by Robert Haralick a professor of Computer Science > at CUNY, can be described as follows: When all of the appellations > experiment when performed on Genesis favors the codes phenomenon, and > the result of the experiment when performed on War and Peace rejects a > codes phenomenon. This finding is a major challenge to the authors of > possible appellations been used in the experiment, no codes phenomenon > would have been detected in Genesis. In other words, even though the > methodology of the 1994 experiment, their War and Peace counterexample > would now be rendered irrelevant, assuming that Haralicks findings > are technically correct. Unfortunately I do not have the expertise to fully evaluate Haralicks paper. However, I think one sentence in their abstract is certainly worth commenting on: We designed an improved protocol for the experiment using statistically more powerful compactness measures and an ELS Random Placement control text population. [1] If I had to guess, it is primarily this improved protocol that is behind the remarkable results of this experiment. > You can download Haralicks paper here http://www.torahcodes.net as > well as other papers in the section marked new. Note that I am not > claiming that Haralicks findings are correct, but only that his > claims should be taken seriously. I am interested to hear how the > anti-codes crowd would intelligently dispute this finding. Torah Codes claims have been taken seriously by its critics for over 10 years. Like you I hope that someone qualified will intelligently dispute Haralicks paper. Unless it is published in peer-reviewed journal, however, I do not not expect a thorough analysis of it. > Also, I recommend anyone who is skeptical about the general codes > phenomenon and knows some basic Hebrew to go here: > http://www.meru.org/Lettermaps/B%27rePole.html > Then combine the picture on that site with the explanation: When the > aleph-beis is counted in base 3 starting at zero, we get the following > relationships: (beis,yud)=(001,100), (vav,taf)=(012,210), > (heh,mem)=(011,110), (lamed,reish)=(1,0,2)=(2,0,1). Notice that every > letter in the picture (except for the first and last) horizontally > pairs with itself or its mirror image. Whether or not you think that > this is all a coincidence, youll have to agree that there is a very > interesting pattern in the first verse of Genesis. Yes, it is quite amusing. [1] http://cs.anu.edu.au/~bdm/dilugim/StatSci/ [2] http://cs.anu.edu.au/~bdm/dilugim/torah.html [3] http://cs.anu.edu.au/~bdm/dilugim/Nations/ [4] http://cs.anu.edu.au/~bdm/dilugim/gans_exp.html [5] http://www.ratio.huji.ac.il/show-dp-abstract.asp?dpNumber=364 [6] http://www.wopr.com/biblecodes/Cities_Overview.htm [7] http://cs.anu.edu.au/~bdm/dilugim/StatSci/gans_rep.html [8] http://www.torahcodes.co.il/debate1.htm [9] http://www.aish.com/seminars/discovery/Codes/Primer/primer1. htm [10] http://www.torahcodes.net/hypoth.pdf [11] http://www.math.toronto.edu/~drorbn/Codes/NationsExtract.html === Subject: Re: Bible Codes Resurrected? > It is true that the choice of appellations is regarded by McKay et al > (1999) to be the most serious problem with the data [1]. However, > nowhere in the paper is it argued that Witztum et al should have used > have used all possible appellations. Maybe not explicitly but it certainly was implied. > In fact, the > authors of the 1999 paper did just that by selecting different > appellations of the names of the same rabbis, forcing a proof that > there are hidden codes in the novel, War and Peace. > This is certainly not the only evidence McKay et al (1999) found to > support their argument that Witztum et al (1994) is ßawed. Aside from > the demonstration by McKay et al that the phenomenon can be replicated > in War and Peace, below is a brief summary of the evidence presented > in McKay et al (1999) and in subsequent papers: > 1. Witztum et al tended to choose options more favorable to their > results when a choice was available [1]. The same was found in > numerous other experiments by Witztum et al [2], and the bias is most > apparent in the 70 nations experiment [3]. This is basically the same argument as I described before. > 2. The P2 value, a measurement used by Witztum et al., was closer to > each other for the two lists of rabbis than what would be expected by > chance. Having them close together makes it appear that the results > are consistent. However, McKay et al. found that when shufßing the > two lists of rabbis together and splitting them in half, the results > were only equal around 1% of the time. The same study was performed on > the rabbis in Gans cities experiment and found similar results [1]. I talked in person with Gans about this a few years ago because I had questions about this. He said that when he did his cities experiment, he did not split the lists up as was done in the WRR paper. In any case, Haralicks paper renders this argument obsolete, assuming that it is correct. > 3. The several independent studies conducted by qualified > mathematicians using data directly from encyclopedias and from > independent experts have found no trace of the codes [1][4][5][6]. Failure in other experiments does not negate the alleged success of this experiment. > And thus, the > verdict from the scientific community was that the methodology in the > 1994 experiment was ßawed and that there was no evidence for a hidden > code phenomenon in Genesis. there were hidden codes in Genesis; it only showed that the original > 1994 experiment methodology was ßawed. > Is there any evidence that could potentially be found that would > refute the *possibility* that there are hidden codes in Genesis? What > about hidden codes War and Peace? That is pretty difficult to do. Sort of like trying to define randomness. Its relatively easy to show that a sequence is not random by finding a pattern. However, showing that there is no conceivable pattern is much more difficult. So there is no real proof that there are no hidden codes in War and Peace although it is pretty safe to assume such. > Furthermore, to their > discredit, the journal Statistical Science did not allow the authors > In fact, the editors of Statistical Science did invite Rips to submit > a reply to McKay et als paper. However, the editors did not agree to > allow Rips to bypass the peer-review process and have his reply > published regardless of its quality [7]. That is unfortunate. However, at that point in time I doubt Rips would > This is nothing new. Witztum and others have posted numerous > rebuttals since McKay et al (1999) was published [8][9], and McKay > has replied to many of them [1][2]. Unfortunately it seems that many > of the researchers who have spent countless hours in the past 10 years > finding ßaw after ßaw in Torah Codes experiments are becoming tired > of the subject [11]. I agree with you on this point. Witztums critiques come down to why his spellings are more legitimate than McKays monkey list. This is very weak since it is subject to so much subjectivity. > The major > finding, discovered by Robert Haralick a professor of Computer Science > at CUNY, can be described as follows: When all of the appellations > experiment when performed on Genesis favors the codes phenomenon, and > the result of the experiment when performed on War and Peace rejects a > codes phenomenon. This finding is a major challenge to the authors of > possible appellations been used in the experiment, no codes phenomenon > would have been detected in Genesis. In other words, even though the > methodology of the 1994 experiment, their War and Peace counterexample > would now be rendered irrelevant, assuming that Haralicks findings > are technically correct. > Unfortunately I do not have the expertise to fully evaluate Haralicks > paper. However, I think one sentence in their abstract is certainly > worth commenting on: > We designed an improved protocol for the experiment using > statistically more powerful compactness measures and an ELS Random > Placement control text population. [1] > If I had to guess, it is primarily this improved protocol that is > behind the remarkable results of this experiment. The improved protocal is described fully in the paper and was motivated at least partially by the critisms in McKays paper. I just read it yesterday and could not find obvious fault with the reasoning. > You can download Haralicks paper here http://www.torahcodes.net as > well as other papers in the section marked new. Note that I am not > claiming that Haralicks findings are correct, but only that his > claims should be taken seriously. I am interested to hear how the > anti-codes crowd would intelligently dispute this finding. > Torah Codes claims have been taken seriously by its critics for over > 10 years. Like you I hope that someone qualified will intelligently > dispute Haralicks paper. Unless it is published in peer-reviewed > journal, however, I do not not expect a thorough analysis of it. I have a feeling that McKay and Simon will take Haralicks claims seriously and try to dispute them regardless of whether it is published in a peer-reviewed journal or not. The fact that it is up on the internet and presents a serious challenge to their claims by someone as distinguished as Prof. Haralick (you can find his resume here: http://prl.cs.gc.cuny.edu/web/LabWebsite/Haralick/main.htm) is enough for them to intelligently try to dispute it. Up until now, McKay and Simon have been winning the codes debate. > Also, I recommend anyone who is skeptical about the general codes > phenomenon and knows some basic Hebrew to go here: > http://www.meru.org/Lettermaps/B%27rePole.html Then combine the picture on that site with the explanation: When the > aleph-beis is counted in base 3 starting at zero, we get the following > relationships: (beis,yud)=(001,100), (vav,taf)=(012,210), > (heh,mem)=(011,110), (lamed,reish)=(1,0,2)=(2,0,1). Notice that every > letter in the picture (except for the first and last) horizontally > pairs with itself or its mirror image. Whether or not you think that > this is all a coincidence, youll have to agree that there is a very > interesting pattern in the first verse of Genesis. > Yes, it is quite amusing. The reason I pointed it out was not to try to convince anyone that Genesis was written by God but to show that there are some patterns in the text which appear not to be by chance. > [1] http://cs.anu.edu.au/~bdm/dilugim/StatSci/ > [2] http://cs.anu.edu.au/~bdm/dilugim/torah.html > [3] http://cs.anu.edu.au/~bdm/dilugim/Nations/ > [4] http://cs.anu.edu.au/~bdm/dilugim/gans_exp.html > [5] http://www.ratio.huji.ac.il/show-dp-abstract.asp?dpNumber=364 > [6] http://www.wopr.com/biblecodes/Cities_Overview.htm > [7] http://cs.anu.edu.au/~bdm/dilugim/StatSci/gans_rep.html > [8] http://www.torahcodes.co.il/debate1.htm > [9] http://www.aish.com/seminars/discovery/Codes/Primer/primer1. htm > [10] http://www.torahcodes.net/hypoth.pdf > [11] http://www.math.toronto.edu/~drorbn/Codes/NationsExtract.html === Subject: Re: Bible Codes Resurrected? > It is true that the choice of appellations is regarded by McKay et al > (1999) to be the most serious problem with the data [1]. However, > nowhere in the paper is it argued that Witztum et al should have used > have used all possible appellations. > Maybe not explicitly but it certainly was implied. Perhaps the following sentences can be interpreted in that way: Since WRR used far less than half of the appellations by which their rabbis were known, the issue of how the selection was made is central to the interpretation of their experiment ... This has led to the widely held misconception that the list was comprehensive or that the selection was rigorous and mechanical. Not so. In any case, the paper does not at any time state that an appropriate list for an experiment attempting to provide evidence of Torah Codes is a combination of the two lists from Witztum et al (1994) and the War and Peace list of Bar-Natan et al (1999). The reason this is inappropriate is because, as McKay et al have shown, Witztum et als lists seem to be tuned to acheive remarkable results in Genesis. Nobody has claimed that combining the War and the effect. > 1. Witztum et al tended to choose options more favorable to their > results when a choice was available [1]. The same was found in > numerous other experiments by Witztum et al [2], and the bias is most > apparent in the 70 nations experiment [3]. > This is basically the same argument as I described before. No, this is a different argument. Please see the section of the paper titled The study of variations (pages 14-20). http://cs.anu.edu.au/~bdm/dilugim/StatSci/StatSci.pdf > 2. The P2 value, a measurement used by Witztum et al., was closer to > each other for the two lists of rabbis than what would be expected by > chance. Having them close together makes it appear that the results > are consistent. However, McKay et al. found that when shufßing the > two lists of rabbis together and splitting them in half, the results > were only equal around 1% of the time. The same study was performed on > the rabbis in Gans cities experiment and found similar results [1]. > I talked in person with Gans about this a few years ago because I had > questions about this. He said that when he did his cities experiment, > he did not split the lists up as was done in the WRR paper. Yes, but Gans didnt compile the appellations and cities on his own. Rather, he obtained the data from Zvi Inbal, a lecturer on the Torah Codes and a friend of Doron Witztum. (As far as I know Inbal has not made any public statement about the origins of the data.) The hypothesis (which is not explicitly stated) seems to be that Witztum compiled the lists expecting them to be used in two seperate experiments, adjusted them to demonstrate remarkable but consistent results (as he did with his previous lists), and gave them to Inbal to give to Gans. This hypothesis seems to be the most consistent with the data. Please see the section titled Traces of naive statistical expectation (pages 20-22) for more information. > Is there any evidence that could potentially be found that would > refute the *possibility* that there are hidden codes in Genesis? What > about hidden codes War and Peace? > That is pretty difficult to do. Sort of like trying to define > randomness. Its relatively easy to show that a sequence is not random > by finding a pattern. However, showing that there is no conceivable > pattern is much more difficult. So there is no real proof that there > are no hidden codes in War and Peace although it is pretty safe to > assume such. I agree. However, after considering the evidence for and against the Torah Codes, I also believe that it is pretty safe to assume that there are no codes in the Torah. > I have a feeling that McKay and Simon will take Haralicks claims > seriously and try to dispute them regardless of whether it is > published in a peer-reviewed journal or not. The fact that it is up on > the internet and presents a serious challenge to their claims by > someone as distinguished as Prof. Haralick (you can find his resume > here: http://prl.cs.gc.cuny.edu/web/LabWebsite/Haralick/main.htm) is > enough for them to intelligently try to dispute it. Up until now, > McKay and Simon have been winning the codes debate. Fortunately they will still be winning even if none of the experts respond to Haralicks paper, since the reliability of any experiment using data from Witztum et als lists must automatically be questioned. > Yes, it is quite amusing. > The reason I pointed it out was not to try to convince anyone that > Genesis was written by God but to show that there are some patterns in > the text which appear not to be by chance. Before it was demonstrated that hidden codes can be found in any book, Bible Codes appeared to not exist by chance (and Im sure you would agree that *some* of the impressive looking codes exist by chance). Before it was demonstrated that hidden patterns of 7 can be found in any book, Panins patterns in the Old Testament and New Testament appeared to not exist by chance: http://cs.anu.edu.au/~bdm/dilugim/panin.html It has not yet been demonstrated that similar patterns to the pattern you pointed out can be found in any book. However, when this pattern becomes the subject of a bestseller or a paper in a peer-reviewed journal I suspect someone knowledgable will be motivated enough demonstrate this. http://www.polesoft.com/refer.html === Subject: Re: Bible Codes Resurrected? > Yes, but Gans didnt compile the appellations and cities on his own. Rather, > he obtained the data from Zvi Inbal, a lecturer on the Torah Codes and a > friend of Doron Witztum. (As far as I know Inbal has not made any public > statement about the origins of the data.) Inbal and Witztum both say that Inbal compiled the date on his own and gave it to Gans. Brendan. === Subject: Re: Bible Codes Resurrected? > Fortunately they will still be winning even if none of the experts respond > to Haralicks paper, since the reliability of any experiment using data from > Witztum et als lists must automatically be questioned. This contradicts what you said before. Before you suggested that Haralick use the appellations from all six lists that you gave. But the six lists that you gave include Witztums lists. Craig === Subject: Re: Bible Codes Resurrected? Fortunately they will still be winning even if none of the experts respond > to Haralicks paper, since the reliability of any experiment using data from > Witztum et als lists must automatically be questioned. > This contradicts what you said before. Before you suggested that > Haralick use the appellations from all six lists that you gave. But > the six lists that you gave include Witztums lists. When, in particular, did I say this? This is what I have said on the subject: The objectivity of the data used by Witztum et al (1994) has been seriously criticized for the reasons I specified in a previous post to this thread. If Haralick wanted to avoid the critcism that his data is biased, he should not be including this data in his experiment at all. In fact, Haralick had many choices about where he derived his data from ... === Subject: Re: Bible Codes Resurrected? ----- Original Message ----- === Subject: Re: Bible Codes Resurrected? > Yet we find that Haralick is using list 2 and 3 (both of which have > been severely critcized) combined with list 6. Why would Haralick use > a list 1 and 2 as part of his data? Perhaps because he realizes he has > no chance of achieving remarkable results unless he uses list 1 or 2. > Or more likely he didnt have access to those lists, as he said in his > paper that he knew of no other publicly released lists. Remember that > McKay did not release these lists in his published paper, only on his > website. I think it is asking a little to much to expect Haralick, who > is a busy man, to have to surf the net in order to find out about this > information. If McKay had published the lists in the journal then it would have been quite time consuming to retype them one character at a time. By publishing the lists on the Internet McKay made them about as easy to obtain as possible. According to the biography you linked, Haralick is a Computer Science professor. Are you really arguing that a Computer Science professor who has spent numerous hours analyzing Torah Codes would not be able to find such easily obtainable data? Even if we assume that Haralick was unaware that the data was publically available or unable to locate it, could he not have send McKay an e-mail asking for the data? I am certain Haralick was aware that this data existed, but nevertheless chose not to use it. > Furthermore, what if Haralick were to have performed his > analysis with these lists and the experiment were successful? Then > McKay could have easily taken the lists down from his website and then > people might accuse Haralick of tuning his lists. Do you really believe that McKay is the only one who has this data after it has been publically available on his website for 4 years? Do you realize that there are about 21 snapshots between October 1999 and any of these snapshots? http://web.archive.org/web/*/http://cs.anu.edu.au/~bdm/ dilugim/StatSci/data. html > It sounds like you are moving the goalposts. In any case, if these > other lists are reasonable, then there is no reason why Haralick > should fear using them. But to accuse him of not having used them > because he knows that they wont work is completely unfounded. It is possible but I consider it very unlikely. Haralick probably considers these lists unreasonable for some reason or another, and will probably cite Witztums numerous objections to these lists. http://www.torahcodes.co.il/emanuel/eman_hb.htm http://www.torahcodes.co.il/emanuel/ema1_eng.htm Responses are available to Witztums claims: http://cs.anu.edu.au/~bdm/dilugim/StatSci/emanuel_rep.html http://cs.anu.edu.au/~bdm/dilugim/StatSci/var_rep.html > This only addresses some of the problems with the data. There may be > similar problems with the improved protocol. For example, why did > Haralick develop an improved protocol rather than the protocol > recommended to Witztum et al by Diaconis, or the protocol actually > used in Witztum et al? This again leaves wiggle room. > protocal. The new protocal addresses these problems and is more > descriptive of the Torah Code hypothesis. And if you read carefully > wiggle room involved with the selection of the new metric. Okay. I have no expertise in mathematics so right now I wont make any additional comments on the protocol, but I do hope that McKay or someone else with expertise takes the time to analyze it. http://www.polesoft.com/refer.html === Subject: Re: Bible Codes Resurrected? > ----- Original Message ----- === > Subject: Re: Bible Codes Resurrected? > Yet we find that Haralick is using list 2 and 3 (both of which have > been severely critcized) combined with list 6. Why would Haralick use > a list 1 and 2 as part of his data? Perhaps because he realizes he has > no chance of achieving remarkable results unless he uses list 1 or 2. > Or more likely he didnt have access to those lists, as he said in his > paper that he knew of no other publicly released lists. Remember that > McKay did not release these lists in his published paper, only on his > website. I think it is asking a little to much to expect Haralick, who > is a busy man, to have to surf the net in order to find out about this > information. > If McKay had published the lists in the journal then it would have been > quite time consuming to retype them one character at a time. By publishing > the lists on the Internet McKay made them about as easy to obtain as > possible. According to the biography you linked, Haralick is a Computer > Science professor. Are you really arguing that a Computer Science professor > who has spent numerous hours analyzing Torah Codes would not be able to find > such easily obtainable data? > Even if we assume that Haralick was unaware that the data was publically > available or unable to locate it, could he not have send McKay an e-mail > asking for the data? > I am certain Haralick was aware that this data existed, but nevertheless > chose not to use it. I think it is safe to say that we both have no idea why Haralick did not use the list on McKays website. The only way to know is to ask him. Regardless of what Haralick is thinking, I think his experiment on its own (assuming that it is as he described it and is correct technically) does give evidence that there is a codes phenomenon in the Torah. The results are consistent with what one would expect if there is a codes phenomenon and inconsistent with the null hypothesis. I eagerly await the response from the McKay and Simon team. I agree that they were successful in their attack of the WRR paper. However, given this new result, Im not certain they will be successful. I hope they will be successful if indeed there is a ßaw in Haralicks work. I saw that you helped McKay write his response to Gans primer on Codes. Perhaps you can make him aware of this new result of Haralick, if he is not already aware? > Furthermore, what if Haralick were to have performed his > analysis with these lists and the experiment were successful? Then > McKay could have easily taken the lists down from his website and then > people might accuse Haralick of tuning his lists. > Do you really believe that McKay is the only one who has this data after it > has been publically available on his website for 4 years? > Do you realize that there are about 21 snapshots between October 1999 and > any of these snapshots? I never knew this. Thats a good idea, as historians will go through this looking at the early days of the internet. > http://web.archive.org/web/*/http://cs.anu.edu.au/~bdm/ dilugim/StatSci/data.h tml > It sounds like you are moving the goalposts. In any case, if these > other lists are reasonable, then there is no reason why Haralick > should fear using them. But to accuse him of not having used them > because he knows that they wont work is completely unfounded. > It is possible but I consider it very unlikely. Haralick probably considers > these lists unreasonable for some reason or another, and will probably cite > Witztums numerous objections to these lists. > http://www.torahcodes.co.il/emanuel/eman_hb.htm > http://www.torahcodes.co.il/emanuel/ema1_eng.htm > Responses are available to Witztums claims: > http://cs.anu.edu.au/~bdm/dilugim/StatSci/emanuel_rep.html > http://cs.anu.edu.au/~bdm/dilugim/StatSci/var_rep.html I doubt that. Thats not Haralicks style. > This only addresses some of the problems with the data. There may be > similar problems with the improved protocol. For example, why did > Haralick develop an improved protocol rather than the protocol > recommended to Witztum et al by Diaconis, or the protocol actually > used in Witztum et al? This again leaves wiggle room. > protocal. The new protocal addresses these problems and is more > descriptive of the Torah Code hypothesis. And if you read carefully > wiggle room involved with the selection of the new metric. > Okay. I have no expertise in mathematics so right now I wont make any > additional comments on the protocol, but I do hope that McKay or someone > else with expertise takes the time to analyze it. > http://www.polesoft.com/refer.html === Subject: Re: Bible Codes Resurrected? When you mix salt crystals and red or black crystals together and really shake them up in a glass container -- you do not end up with an evenly mixed pinkish or grayish mixture -- instead there are striations of colour. Similarly, for any sufficiently long text. You will be able to do word wrap of various lengths and it would be very surprising if some words and/or phrases did not show up at least a few times. -- Casey === Subject: Re: Bible Codes Resurrected? > Then combine the picture on that site with the explanation: When the > aleph-beis is counted in base 3 starting at zero, we get the following > relationships: (beis,yud)=(001,100), (vav,taf)=(012,210), > (heh,mem)=(011,110), (lamed,reish)=(1,0,2)=(2,0,1). Notice that every > letter in the picture (except for the first and last) horizontally > pairs with itself or its mirror image. Whether or not you think that > this is all a coincidence, youll have to agree that there is a very > interesting pattern in the first verse of Genesis. Well, you sound like a perfect crackpot. I think you might want to think about your post once more. Bible Codes? What are you talking about? -- Eray Ozkural === Subject: Re: Bible Codes Resurrected? >> Whether or not you think that >> this is all a coincidence, youll have to agree that there is a very >> interesting pattern in the first verse of Genesis. > Well, you sound like a perfect crackpot. I think you might want to > think about your post once more. > Bible Codes? What are you talking about? Since hes not putting forth a theory, but asking a question, he hardly sounds like a crackpot. The responses to his question have been only comments about how coincidences happen. The Bible Codes assertions are deeper than that. Everyone acknowledges that coincidences happen. The assertion here is that in Torah, the coincidences happen way too often to be just random. Specifically, it appears that the new paper shows that the frequency of coincidences is much higher in the Torah than in War and Peace. So Craig asks whether this is a legitimate observation. No one addresses this, but instead gives the pat rebuttal to the 1994 paper. It makes me wonder if anyone read Craigs post. Bart === Subject: Re: Bible Codes Resurrected? >Specifically, it appears that the new paper shows that >the frequency of coincidences is much higher in the Torah >than in War and Peace. > It may appear so; however, where does it say that? > Since this is a math group -- is there a quantitative comparison? > How many letters in War and Peace? Torah? > What Id be more interested in, is if there is a pattern in the number > of recognizable words/phrases for different letter wrappings -- from > 2, 3, 4, columns etc. up to 1/3 the length of the book. > I wonder if the number of patterns follows a normal curve. > Have other works been analyzed? > Doby-Mick by Mervin Helville http://www.crank.net/bible.html has lots of links to crank sites based on this idea, and also an anti crank site showing codes in Moby Dick: http://cs.anu.edu.au/~bdm/dilugim/moby.html Of course, I suspect that the Rev. Spooner could find many many more. > Jord Lim by Coseph Jonrad > Letham by Shilliam Wakespeare > The Flord of the Lies by Gilliam Wolding Gill Bolding to her friends. === Subject: Re: Bible Codes Resurrected? >Specifically, it appears that the new paper shows that >the frequency of coincidences is much higher in the Torah >than in War and Peace. > It may appear so; however, where does it say that? > Since this is a math group -- is there a quantitative comparison? > How many letters in War and Peace? Torah? A brief introduction of the scientific Torah Codes dispute can be http://cs.anu.edu.au/~bdm/dilugim/Chance.pdf The actual paper Craig referred to can be found at this URL: http://www.torahcodes.net/hypoth.pdf === Subject: Re: Bible Codes Resurrected? >>Specifically, it appears that the new paper shows that >>the frequency of coincidences is much higher in the Torah >>than in War and Peace. > It may appear so; however, where does it say that? > Since this is a math group -- is there a quantitative comparison? According to the OP, thats exactly the experiment performed in the paper. I sure dont care one way or the other. My point was that the responses to the OP were as if the OPs question was much more shallow than it really was. Bart === Subject: Re: Bible Codes Resurrected? >Specifically, it appears that the new paper shows that >the frequency of coincidences is much higher in the Torah >than in War and Peace. Thats hardly surprising, since the Torah allows you o fill in any vowels you like to create meaningful words, whereas with War and Peace the spelling is fixed for vowels and consonants. -- Stan Brown, Oak Road Systems, Tompkins County, New York, USA http://OakRoadSystems.com/ And if youre afraid of butter, which many people are nowa- days, (long pause) you just put in cream. --Julia Child === Subject: Re: Bible Codes Resurrected? >>Specifically, it appears that the new paper shows that >>the frequency of coincidences is much higher in the Torah >>than in War and Peace. > Thats hardly surprising, since the Torah allows you o fill in any > vowels you like to create meaningful words, whereas with War and > Peace the spelling is fixed for vowels and consonants. Recall that the original rebuttal paper DID find the high frequency of coincidences in War and Peace. The OPs question was, In this new investigation, supposedly done with more statistical sense, the Torah beat War and Peace. Is this significant? Bart === Subject: Re: Bible Codes Resurrected? > The Bible Codes assertions are deeper than that. Everyone > acknowledges that coincidences happen. The assertion here > is that in Torah, the coincidences happen way too often > to be just random. Rubbish. > Specifically, it appears that the new paper shows that > the frequency of coincidences is much higher in the Torah > than in War and Peace. Did you remove the vowels from the W&P text? Should have some consequence on probability, me thinks. (Hebrew is written without vowels) === Subject: Re: Bible Codes Resurrected? === >Subject: Re: Bible Codes Resurrected? >Message-id: <58Pnd.30702$b%6.1484858@phobos.telenet-ops.be> The Bible Codes assertions are deeper than that. Everyone >> acknowledges that coincidences happen. The assertion here >> is that in Torah, the coincidences happen way too often >> to be just random. >Rubbish. >> Specifically, it appears that the new paper shows that >> the frequency of coincidences is much higher in the Torah >> than in War and Peace. >Did you remove the vowels from the W&P text? Should have some consequence on >probability, me thinks. >(Hebrew is written without vowels) Except when it isnt. I just picked up a copy of the U.S. News and World Reports bible codes and in Cracking the Bible Code it says: Some of the oldest Hebrew texts, in fact, omitted vowels altogether, scholars say, while later writings used them sporadically. Virtually all versions of the Hebrew Bible known to us today employ a complex mixture of full and defective spelling that is not even consistent for the same words. Incidentally, I really liked the quote at the beginning of this Isiaiah 45:18-19 I am the Lord, and there is no other. I did not speak in secret, in a land of darkness; I did not say to the offspring of Jacob, Seek me in chaos. I the Lord speak the truth, I declare what is right. That passage seems most appropriate since it seems to imply that God does not use secret codes. But it differs from the KJV translation: Isiaiah 45:18-19 I am the Lord, and there is none else. I have not spoken in secret, in a dark place of the earth:; I said not unto the seed of Jacob, Seek ye me in vain: I the Lord speak righteousness, I declare things that are right. Seek me in chaos and Seek me in vain is _not_ a subtle difference in translation. It completely changes the whole passage. -- Mensanator Ace of Clubs === Subject: Re: Bible Codes Resurrected? >> The Bible Codes assertions are deeper than that. Everyone >> acknowledges that coincidences happen. The assertion here >> is that in Torah, the coincidences happen way too often >> to be just random. >Rubbish. Its not rubbish. I reported exactly correctly what the Bible Codes folks are asserting. > Did you remove the vowels from the W&P text? ME? I didnt write the paper and Im not going to read it either. All I did was to point out that the responders didnt understand the OPs question. Just like you didnt understand my post. Bart === Subject: Re: Bible Codes Resurrected? >Did you remove the vowels from the W&P text? Should have some consequence on >probability, me thinks. >(Hebrew is written without vowels) IIRC this was done using a Hebrew translation of War and Peace. It would be silly to make this kind of comparison using texts in different languages. There still might be problems due to the difference between biblical Hebrew and modern Hebrew. Robert Israel israel@math.ubc.ca Department of Mathematics http://www.math.ubc.ca/~israel University of British Columbia Vancouver, BC, Canada === Subject: Re: Bible Codes Resurrected? [Bible code stuff] >Well, you sound like a perfect crackpot. A _perfect_ crackpot? Surely that titles reserved for JSH! :-) -- Stan Brown, Oak Road Systems, Tompkins County, New York, USA http://OakRoadSystems.com/ And if youre afraid of butter, which many people are nowa- days, (long pause) you just put in cream. --Julia Child === Subject: Re: Bible Codes Resurrected? >Equidistant Letter Sequences in the Book of Genesis which claimed to >find evidence for hidden codes in the Hebrew text of Genesis. http://www.math.temple.edu/~paulos/bibcodes.html -- Stan Brown, Oak Road Systems, Tompkins County, New York, USA http://OakRoadSystems.com/ And if youre afraid of butter, which many people are nowa- days, (long pause) you just put in cream. --Julia Child === Subject: Re: Bible Codes Resurrected? >Equidistant Letter Sequences in the Book of Genesis which claimed to >find evidence for hidden codes in the Hebrew text of Genesis. > http://www.math.temple.edu/~paulos/bibcodes.html As do other mathematicians: http://www.math.caltech.edu/code/petition.html === Subject: Re: Bible Codes Resurrected? >> Uh-huh. John Allen Paulos disposed of that idea >As do other mathematicians: http://www.math.caltech.edu/code/petition.html I was unaware of that page, but I have to confess Im a little disappointed. They state that there are problems with the 1994 paper but dont state what the problems are. -- Stan Brown, Oak Road Systems, Tompkins County, New York, USA http://OakRoadSystems.com/ And if youre afraid of butter, which many people are nowa- days, (long pause) you just put in cream. --Julia Child === Subject: Re: Bible Codes Resurrected? >> Uh-huh. John Allen Paulos disposed of that idea >As do other mathematicians: http://www.math.caltech.edu/code/petition.html > I was unaware of that page, but I have to confess Im a little > disappointed. They state that there are problems with the 1994 paper > but dont state what the problems are. The problems can be found in the paper below: http://cs.anu.edu.au/~bdm/dilugim/StatSci/ === Subject: Re: Bible Codes Resurrected? >>As do other mathematicians: http://www.math.caltech.edu/code/petition.html >> I was unaware of that page, but I have to confess Im a little >> disappointed. They state that there are problems with the 1994 paper >> but dont state what the problems are. >The problems can be found in the paper below: >http://cs.anu.edu.au/~bdm/dilugim/StatSci/ educated! -- Stan Brown, Oak Road Systems, Tompkins County, New York, USA http://OakRoadSystems.com/ And if youre afraid of butter, which many people are nowa- days, (long pause) you just put in cream. --Julia Child === Subject: Re: Bible Codes Resurrected? funny; they did an ELS of Kaczynskis Manifesto, getting b mail o m b s, or like that, and readers are welcome to find Free Ted! in it, as well. >http://cs.anu.edu.au/~bdm/dilugim/StatSci/ --Harry Potter wants you, in Sudan! http://larouchepub.com === Subject: Re: Bible Codes Resurrected? posting-account=UtgH7gwAAACpBhTelVPOXNP7RAfbtQrK Do you have any concept of how easy it is to find hidden words in _any_ sufficiently large piece of text? To demonstrate how silly this is, I created The Shakespeare Code Start with a well known passage (Hamlets Soliloquy) and remove all spaces and punctuation. Now wrap the text in a spiral: (this requires a monospaced font to view correctly) yeltgnseptyltuovednoitaMmuslwaeskiir inaursssootehtdnaehcatRaeseaelkierse htnrutotfbhidotmehtdnEgnhnrtheadwpyv usdnnhrhdeoemraekatoTroieoertdmntrmi mttstaseewutsasgnilseheshchorssuaell buhpatwraisoanbonsitrtnotatmawuehtle lruunpretsasgdlhtsiterupdsyseathtnad ynszdaoshhnlaaeenroahetpniaibletseee tatzsTnpwddeirrqotehtfroetmhdeihrdbr hwhlWigehtnenriutobtefoyeoatlhutenso areEeetcaoapsonetobehufbwtefutqahant nyNsanhttdtntwtstionwssdyrrfoesettog kaatttetdiuoaShemindtounaidowvidohsn ynthumphrermSofoutrageoaseodoohrogio odieneraetaOeaoftroublesohtehlteturl ulvwdrotaoLreandbyasleeptselwdhtyood Now, all one has to do is play word search to find hidden messages. But only use diagonals so as not to pick up actual words from the quotation. Ive capitalized three words: NEWT TERM LOSS which leads to the conclusion that Shakespeare predicted Gingrichs defeat in the 1998 Congressional election! Spooky, eh? === Subject: Re: Bible Codes Resurrected? I dont get how you wrapped the text in a spiral, but thats a great spoof of the whole BC sophistry. the question is, of course, did you search for those terms via an increasing modulo, or did you construct it in some other way? > Start with a well known passage (Hamlets Soliloquy) and remove > all spaces and punctuation. Now wrap the text in a spiral: > (this requires a monospaced font to view correctly) > yeltgnseptyltuovednoitaMmuslwaeskiir > inaursssootehtdnaehcatRaeseaelkierse > htnrutotfbhidotmehtdnEgnhnrtheadwpyv > usdnnhrhdeoemraekatoTroieoertdmntrmi > mttstaseewutsasgnilseheshchorssuaell > buhpatwraisoanbonsitrtnotatmawuehtle > lruunpretsasgdlhtsiterupdsyseathtnad > ynszdaoshhnlaaeenroahetpniaibletseee > tatzsTnpwddeirrqotehtfroetmhdeihrdbr > hwhlWigehtnenriutobtefoyeoatlhutenso > areEeetcaoapsonetobehufbwtefutqahant > nyNsanhttdtntwtstionwssdyrrfoesettog > kaatttetdiuoaShemindtounaidowvidohsn > ynthumphrermSofoutrageoaseodoohrogio > odieneraetaOeaoftroublesohtehlteturl > ulvwdrotaoLreandbyasleeptselwdhtyood > Now, all one has to do is play word search to find hidden messages. > But only use diagonals so as not to pick up actual words from the > quotation. > Ive capitalized three words: > NEWT TERM LOSS --Give Earth a Trickier Dick Cheeny -- out of office, after gigayears! http://tarpley.net/bush12.htm http://www.benfranklinbooks.com/ http://members.tripod.com/~american_almanac http://www.wlym.com/pdf/iclc/howthenation.pdf http://www.rand.org/publications/randreview/issues/rr.12.00/ http://www.rwgrayprojects.com/synergetics/plates/figs/plate02. html === Subject: Re: Bible Codes Resurrected? === >Subject: Re: Bible Codes Resurrected? >I dont get how you wrapped the text >in a spiral, Are you familiar with Ulams Spiral, where integers are placed in a spiral pattern? 765 814 923 Extending that out to a 100x100 grid, the primes seem to be aligned in straight lines. For my spiral I used letters instead of numbers. To be or not to be becomes Tobeornottobe wrapped in a counter-clockwise spiral nro oTe tob tobe >but thats a great spoof >of the whole BC sophistry. the question is, of course, >did you search for those terms via an increasing modulo, >or did you construct it in some other way? I didnt use any sort of modulo, I only looked at letter patterns that were in contiguous diagonal lines. When I first built the spiral, I had a program generate every possible word of 3, 4, 5, 6, 7 and 8 letters. I ended up with something like a half million words, most of which were garbage, of course. But I didnt have any way of spell-checking the list to discard the chaff. So I put the word list aside for 9 months until I got a Linux system and figured out how to write a shell script to process the entire list. I managed to sift out a couple thousand legitimate words. Then I simply looked through the list for something interesting. Curiously, it was during that 9 month delay that Gingrich lost his re-election. Had I done the spell-check at the time I created the word list, the three words NEWT TERM LOSS would not have struck me as being interesting. Its easy to predict the past. >> Start with a well known passage (Hamlets Soliloquy) and remove >> all spaces and punctuation. Now wrap the text in a spiral: >> (this requires a monospaced font to view correctly) >> yeltgnseptyltuovednoitaMmuslwaeskiir >> inaursssootehtdnaehcatRaeseaelkierse >> htnrutotfbhidotmehtdnEgnhnrtheadwpyv >> usdnnhrhdeoemraekatoTroieoertdmntrmi >> mttstaseewutsasgnilseheshchorssuaell >> buhpatwraisoanbonsitrtnotatmawuehtle >> lruunpretsasgdlhtsiterupdsyseathtnad >> ynszdaoshhnlaaeenroahetpniaibletseee >> tatzsTnpwddeirrqotehtfroetmhdeihrdbr >> hwhlWigehtnenriutobtefoyeoatlhutenso >> areEeetcaoapsonetobehufbwtefutqahant >> nyNsanhttdtntwtstionwssdyrrfoesettog >> kaatttetdiuoaShemindtounaidowvidohsn >> ynthumphrermSofoutrageoaseodoohrogio >> odieneraetaOeaoftroublesohtehlteturl >> ulvwdrotaoLreandbyasleeptselwdhtyood >> Now, all one has to do is play word search to find hidden messages. >> But only use diagonals so as not to pick up actual words from the >> quotation. >> Ive capitalized three words: >> NEWT TERM LOSS >--Give Earth a Trickier Dick Cheeny -- out of office, after gigayears! >http://tarpley.net/bush12.htm >http://www.benfranklinbooks.com/ >http://members.tripod.com/~american_almanac >http://www.wlym.com/pdf/iclc/howthenation.pdf >http://www.rand.org/publications/randreview/issues/rr.12.00/ >http://www.rwgrayprojects.com/synergetics/plates/figs/plate02 .html -- Mensanator Ace of Clubs === Subject: Re: Bible Codes Resurrected? I see; I had seend Ulams spiral, before. its pretty obvious, though, from the context of skip codes, as used by scribes as a check on their copying, that they just assembled a program, into which was input what ever words were wished to be found, and skipped throught the ring of text, with an increasing modulus until the **** was found. of course, all of it was ex post facto, except for the one that the evil orthodox clowns had Drosnin review, that Rabin would be assassinated. > wrapped in a counter-clockwise spiral > nro > oTe > tob > tobe > I didnt use any sort of modulo, I only looked at letter patterns > that were in contiguous diagonal lines. When I first built the spiral, > I had a program generate every possible word of 3, 4, 5, 6, 7 and 8 > letters. I ended up with something like a half million words, most > of which were garbage, of course. But I didnt have any way of > spell-checking the list to discard the chaff. > the word list, the three words NEWT TERM LOSS would not > have struck me as being interesting. Its easy to predict the past. --ils duces dEnron! http://larouchepub.com === Subject: tessellations by support1.mathforum.org (8.11.6/8.11.6/The Math Forum, $Revision: 1.9 primary) id iAJL0VF16807; A few years ago I worked with a math PhD who had a poster on the wall called the 13 semi-perfect tessellations or something along those lines. An example is Octagons and Squares. Im trying to find out where I can buy this poster. Can anyone help? Its for an elementary school. === Subject: Re: tessellations > A few years ago I worked with a math PhD who had a poster on the wall called the 13 semi-perfect tessellations or something along those lines. An example is Octagons and Squares. > Im trying to find out where I can buy this poster. Can anyone help? > Its for an elementary school. http://members.cox.net/tessellations/Posters.html Something like this...? Pawel Gladki === Subject: Re: NEAT PRODUCTS OF TRIG FUNCTIONS by support1.mathforum.org (8.11.6/8.11.6/The Math Forum, $Revision: 1.9 primary) id iAJL0Vj16794; I can see now that this string should have been entitled Neat but please do not stop now! There are a couple I have not been able to verify, and I see no general method to my solution madness that suggests a constructive approach. I even wonder how some of these were generated or discovered! So, if you would let me know your solutions or methods I would be very grateful! Also, if anybody has others, why not post them here? Most of my verifications involve identities and minimal polynomials found for these (necessarily algebraic) values of trig functions of angles rationally commensurate with pi. Some are brief, while others are somewhat tedious; perhaps, unnecessarily so. I would love to exchange any notes or ideas on this genre of interesting and >I am seeking examples of complicated combinations of trig functions >that have simple values (e. g., rational ones), even though the >functions themselves may not. One such example is the product > P = cos(20)cos(40)cos(80) >(where angles are measured in degrees), whose value equals 1/8. I >would appreciate knowing about any similar relationships. >You might be interested in a surprising direct calculation of this >value, which uses the fact that > cos(60) = 1/2, >and which is outlined below. >The proof I had found in high school was done by multiplying both >sides by 8sin(20) and using the sine double angle identity to obtain > 8Psin(20) = sin(160), >from which the result follows (since 20 and 160 are supplementary). >This admits generalizations (none so nice found) and modifications, >such as the more obfuscatory product of the same three numbers: > P = sin(10)sin(50)sin(70). >My new one uses the identities > cos(2A) = 2[cos(A)]^2 - 1 > cos(3A) = 4[cos(A)]^3 - 3[cos(A)] > cos(4A) = 8[cos(A)]^4 - 8[Cos(A)]^2 + 1. >We let > u = cos(20). >The second of these implies > 4u^3 - 3u = 1/2, >and our product becomes > P = u[2u^2 - 1][8u^4 - 8u^2 + 1]. >Some rearrangement and serpendipitous recognitions lead to the result: > P = [2u^3 - u][8u^4 - 6u^2 - 2u^2 + 1] > = (1/2)[4u^3 - 3u + u][2u(4u^3 - 3u)- 2u^2 + 1] > = (1/2)[1/2 + u][u - 2u^2 + 1] > = (1/4)[-4u^3 + 3u +1] > = (1/4)[-1/2 + 1] > = 1/8. >Ta-DA!!! >I note in passing that this is a clever variant of a purely >mechanical technique which may be used to collapse any polynomial in > u = cos(20) >to at worst a quadratic one. Here, the process terminates with the >constant 1/8. === Subject: Fourier Series and sum (-1)^p/(2p+1)^2 by support1.mathforum.org (8.11.6/8.11.6/The Math Forum, $Revision: 1.9 primary) id iAJL0Wh16833; Does someone know a function whose Fourier series can compute the following sum : sum from p=0 to infinite of (-1)^p/(2p+1)^2 ? === Subject: Re: Fourier Series and sum (-1)^p/(2p+1)^2 > Does someone know a function whose Fourier series can compute the following > sum : > sum from p=0 to infinite of (-1)^p/(2p+1)^2 ? I dont, but it might be of interest to know the above sum equals the integral of (arctan(x))/x over [0,1]. === Subject: Re: Fourier Series and sum (-1)^p/(2p+1)^2 by support1.mathforum.org (8.11.6/8.11.6/The Math Forum, $Revision: 1.9 primary) id iAJLF5q18673; >Does someone know a function whose Fourier series can compute the following sum : >sum from p=0 to infinite of (-1)^p/(2p+1)^2 ? Try looking here. http://mathworld.wolfram.com/CatalansConstant.html Nick === Subject: Re: Fourier Series and sum (-1)^p/(2p+1)^2 by support1.mathforum.org (8.11.6/8.11.6/The Math Forum, $Revision: 1.9 primary) id iAJLV9T20209; OK. === Subject: Has the world gone mad? Isnt it true that R (the real line) and R/{0} (the real line with the origin removed) *are not* isomorphic to each other (under the usual ordering of the real numbers)? I ask because a certain very helpful Mr. Liou answered a question of by pointing me to a paper (by a certain Baumgartner) which says that, assuming the continuum hypothesis, all aleph-one-dense sets of reals could be isomorphic. I havent found a copy of the actual paper, but all references Ive found to it define an aleph-one-dense set of reals the obvious way, as a set that has aleph-one-many members in any interval of reals you care to name. Both R and R/{0} would appear to qualify, no? And if so, why does the following proof fail to contradict Baumgartners statement trivially? Let f : R/{0} -> R be a purported order-isomorphism. Call fs image on the negative reals N, and fs image on the positive reals P. N and P are then a partition of the reals into a left and a right subset. N has a least upper bound in R, and P has a greatest lower bound, and clearly they are the same. Call their shared bound b. b must be in N or in P. Assume without loss of generality that b is in N. Then its pre-image under f is some negative real number x. But then there is a negative real closer to the origin (x/2, for example) which has to be mapped to a point in N that is (because f preserves order) greater than b. There is no such point, so R/{0} and R have no isomorphism. === Subject: Re: Has the world gone mad? |I havent found a copy of the actual paper, but |all references Ive found to it define an aleph-one-dense set of reals |the obvious way, as a set that has has _exactly_ | aleph-one-many members in any |interval of reals you care to name. Both R and R/{0} would appear to |qualify, no? Not unless the continuum hypothesis is true. Evidently the Baumgartner statement, that all aleph-1-dense sets of reals are order-isomorphic, contradict the continuum hypothesis. This is a natural generalization of Cantors theorem that all Keith Ramsay === Subject: Re: Has the world gone mad? Keith is exactly right -- my misunderstanding was to assume aleph-one dense meant having *at least* aleph-one-many points in any interval, when Baumgartner wants it to mean *exactly* aleph-one-many points. Apologies to anyone whose time was wasted on this; Ill try to post only substantive questions in the future. On the other hand, someone was nice enough to mail me the link the Baumgartners paper, which I couldnt find myself. http://matwbn.icm.edu.pl/ksiazki/fm/fm79/fm7911.pdf Its amazing how much complicated structure might be hiding in so innocuous-sounding a thing as the real line. Theres a good overview paper on different properties the real line might have under different set-theoretic hypotheses, by K. Kunen and F. Tall, here: http://www.math.toronto.edu/tall/publications/48.pdf === Subject: Re: Has the world gone mad? > Isnt it true that R (the real line) and R/{0} (the real line with the > origin removed) *are not* isomorphic to each other (under the usual > ordering of the real numbers)? They arent order-isomorphic: R has the least-upper-bound property but R{0} doesnt. -- Robin Chapman, www.maths.ex.ac.uk/~rjc/rjc.html Lacan, Jacques, 79, 91-92; mistakes his penis for a square root, 88-9 Francis Wheen, _How Mumbo-Jumbo Conquered the World_ === Subject: Re: Has the world gone mad? origin removed) *are not* isomorphic to each other (under the usual > ordering of the real numbers)? > They arent order-isomorphic: R has the least-upper-bound property > but R{0} doesnt. Indeed. In contrast, Q is order isomorphic to Q0. Z is order isomorphic to Z0. === Subject: Re: Has the world gone mad? > Isnt it true that R (the real line) and R/{0} (the real line with the > origin removed) *are not* isomorphic to each other (under the usual > ordering of the real numbers)? > They arent order-isomorphic: R has the least-upper-bound property > but R{0} doesnt. > Indeed. In contrast, > Q is order isomorphic to Q0. > Z is order isomorphic to Z0. The statement about Z is easily seen to be true. I doubt the statement about Q - assuming that the conventional order is being used for both Q and Q {0}. -- Chris Henrich The total lack of evidence is the surest sign that the conspiracy is working. === Subject: Re: Has the world gone mad? >> Isnt it true that R (the real line) and R/{0} (the real line with >> the origin removed) *are not* isomorphic to each other (under the >> usual ordering of the real numbers)? >> They arent order-isomorphic: R has the least-upper-bound property >> but R{0} doesnt. >> Indeed. In contrast, >> Q is order isomorphic to Q0. >> Z is order isomorphic to Z0. > The statement about Z is easily seen to be true. I doubt the statement > about Q - assuming that the conventional order is being used for both > Q and Q {0}. Its true. All countably infinite totally ordered sets with no maximum and minimum and with a element strictly between any two given distinct elements are order-isomorphic. -- Robin Chapman, www.maths.ex.ac.uk/~rjc/rjc.html Lacan, Jacques, 79, 91-92; mistakes his penis for a square root, 88-9 Francis Wheen, _How Mumbo-Jumbo Conquered the World_ === Subject: Re: Has the world gone mad? >> Q is order isomorphic to Q0. >> Z is order isomorphic to Z0. > The statement about Z is easily seen to be true. I doubt the statement > about Q - assuming that the conventional order is being used for both > Q and Q {0}. > Its true. All countably infinite totally ordered sets with no maximum > and minimum and with a element strictly between any two given distinct > elements are order-isomorphic. Its a bear, or at least a bob cat to prove. List the elements and one by one order isomorphically fit them into the diatic rationals Z[1/2]. Then showing that the mapping is surjective, conclude the so described linear order is order isomorphic to Z[1/2]. Thus as Q and Q0 both have the described property, theyre both order isomorphic to Z[1/2], hence to each other. Now you see how removal of finite many elements from Q or Z, produces any order isomorphic set. === Subject: Re: Has the world gone mad? > Q is order isomorphic to Q0. > Z is order isomorphic to Z0. >> The statement about Z is easily seen to be true. I doubt the statement >> about Q - assuming that the conventional order is being used for both >> Q and Q {0}. >> Its true. All countably infinite totally ordered sets with no maximum >> and minimum and with a element strictly between any two given distinct >> elements are order-isomorphic. >Its a bear, or at least a bob cat to prove. >List the elements and one by one order isomorphically fit them into the >diatic rationals Z[1/2]. Then showing that the mapping is surjective, >conclude the so described linear order is order isomorphic to Z[1/2]. It is much easier than that to prove. Let A and B be the two sets, and denote the orderings of them by <_A and <_B respectively, and the enumerations of them by q_A and q_B respectively. Let A_j and B_j be the subsets chosen at time j, and let f_j be the 1-1 order-preserving mapping from A_j into B_j. A_0 and B_0 are the empty set, and as A_j and B_j will have j elements, AA_j and BB_j will be divided into j+1 countable subsets in their orderings <_A and <_B. If j=2k, let a_j be the q_A first element of AA_j and let b_j be the first element of BB_j in the corresponding countable subset of BB_j. If j=2k+1, reverse the roles of A and B. Let f_{j+1} = f_j u {}. It is now easy to prove by induction that the relevant properties of A_j and B_j are preserved, and that all of A and B are used. -- This address is for information only. I do not claim that these views are those of the Statistics Department or of Purdue University. Herman Rubin, Department of Statistics, Purdue University hrubin@stat.purdue.edu Phone: (765)494-6054 FAX: (765)494-0558 === Subject: Re: Has the world gone mad? >> Q is order isomorphic to Q0. >> Z is order isomorphic to Z0. > The statement about Z is easily seen to be true. I doubt the statement > about Q - assuming that the conventional order is being used for both > Q and Q {0}. > Its true. All countably infinite totally ordered sets with no maximum > and minimum and with a element strictly between any two given distinct > elements are order-isomorphic. > Its a bear, or at least a bob cat to prove. > List the elements and one by one order isomorphically fit them into the > diatic rationals Z[1/2]. Then showing that the mapping is surjective, > conclude the so described linear order is order isomorphic to Z[1/2]. > Thus as Q and Q0 both have the described property, theyre both > order isomorphic to Z[1/2], hence to each other. > Now you see how removal of finite many elements from Q or Z, produces > any order isomorphic set. I think it is important to choose the next dyadic rational at each step with some care. If it is to be less than all previously chosen numbers, or greater than all, it should be the integer with the smallest absolute value consitent with this requirement. If it is to be between two previously chosen numbers, it should be the dyadic rational with the smallest possible denominator. Whats really a bear, and a bear with a toothache, is trying to draw the graph of that mapping. -- Chris Henrich God just doesnt fit inside a single religion. === Subject: Re: Has the world gone mad? === Subject: Re: Has the world gone mad? >> Q is order isomorphic to Q0. > Its true. All countably infinite totally ordered sets with no > maximum and minimum and with a element strictly between any two > given distinct elements are order-isomorphic. >> Its a bear, or at least a bob cat to prove. >> List the elements and one by one order isomorphically fit them into >> the diatic rationals Z[1/2]. Then showing that the mapping is >> surjective, conclude the so described linear order is order >> isomorphic to Z[1/2]. >> Thus as Q and Q0 both have the described property, theyre both >> order isomorphic to Z[1/2], hence to each other. > I think it is important to choose the next dyadic rational at each > step with some care. If it is to be less than all previously chosen > numbers, or greater than all, it should be the integer with the > smallest absolute value consitent with this requirement. If it is > to be between two previously chosen numbers, it should be the dyadic > rational with the smallest possible denominator. For wherever theyre worth or not worth, heres my brief outline notes or chronicals of the bob cat fight I had. Do note the first part was showing any countable linear order embeds in the dyadic rationals. In particular, any countable ordinal embedds in the dyadic rationals. Ordermorphic is short for order isomorphic. -- eta, order type rationals countable linear order S ==> S embeds in dyadic rationals bounded countable dense linear order S ==> S ordermorphic Z[1/2] / [0,1] unbounded countable dense linear order S ==> S ordermorphic Z[1/2], Q Add top, bottom to S as needed, remove afterwards Let D = dyadic rationals = Z[1/2] / [0,1] Enumerate S: s0 = bottom, s1 = top, s2, s3,... Let f(s0) = 0, bn = max { si | i < n, si < sn } f(s1) = 1, tn = min { si | i < n, sn < si } f(sn) = (f(bn) + f(tn))/2 for n > 1 For all j,k, sj < sk ==> f(sj) < f(sk). (induction) s0 = bottom < top = s1; f(s0) = 0 < 1 = f(s1). (case n = 2) If for all j,k < n, sj < sk ==> f(sj) < f(sk) then for all j,k < n+1, sj < sk ==> f(sj) < f(sk) For i < n < n+1: f(sn) = (f(bn)+f(tn))/2 (case n = n+1) some j,k < n with sj = bn < sn < tn = sk; f(bn) < f(tn) f(bn) = 2f(bn)/2 < (f(bn)+f(tn))/2 = f(sn) f(sn) = (f(bn)+f(tn))/2 < 2f(tn)/2 = f(tn) if si < sn: si <= bn; f(si) <= f(bn) < f(sn) if sn < si: tn <= si; f(sn) < f(tn) <= f(si) f increasing injection into D dense linear order S ==> f surjection. If f(S) /= D: let m be smallest m for which n/2^m in Df(S) some b,t with f(b) = (n-1)/2^m, f(t) = (n+1)/2^m let n be smallest n with sn in (b,t); by construction: f(sn) = (f(b) + f(t))/2 = n/2^m which cannot be -- > Whats really a bear, and a bear with a toothache, > is trying to draw the graph of that mapping. Dont smell like a shaggy dog if youre out to out fox a bob cat. ;-) ---- === Subject: Re: Has the world gone mad? days. My association with the Department is that of an alumnus. >Isnt it true that R (the real line) and R/{0} (the real line with the >origin removed) *are not* isomorphic to each other (under the usual >ordering of the real numbers)? Order isomorphic? >I ask because a certain very helpful Mr. Liou answered a question of >by pointing me to a paper (by a certain Baumgartner) which says that, >assuming the continuum hypothesis, all aleph-one-dense sets of reals >could be isomorphic. I havent found a copy of the actual paper, but >all references Ive found to it define an aleph-one-dense set of reals >the obvious way, as a set that has aleph-one-many members in any >interval of reals you care to name. Both R and R/{0} would appear to >qualify, no? Dont you think that a precise knowledge of what Baumgartner calls aleph-one-dense and what Baumgartner calls isomorphic are *incredibly* important in trying to figure this out? > And if so, why does the following proof fail to >contradict Baumgartners statement trivially? Because we dont know what Baumgartners actual statement is, because we dont know what it is he calls aleph-one-dense or what it is he calls isomorphic? Note in particular the use of the conditional could in your paraphrase. What does two sets could be isomorphic mean, as opposed to are isomorphic? -- Its not denial. Im just very selective about what I accept as reality. --- Calvin (Calvin and Hobbes) Arturo Magidin magidin@math.berkeley.edu === Subject: quaternions what is the point of quaternions? they are all the square root of -1. the only thing of interest about them is their relationships among each other... completely arbitrary to me. === Subject: Re: quaternions at 02:00 PM, SharpNova@gmail.com (David Bandel) said: >what is the point of quaternions? Which point? The historical origins? The applications? The place in theory? >they are all the square root of -1. No. 1+I+j, for example, is not a square root of -1. >the only thing of interest about them is their relationships among >each other No, thats not the only thing of intereset, but if you believe that you know the answer then why are you asking? >completely arbitrary to me. I can live with that, but heres a free clue: if you want to ask a question, then dont presuppose that you know the answer. More people will be willing to help you if they believe that youre willing to listen. -- Shmuel (Seymour J.) Metz, SysProg and JOAT Unsolicited bulk E-mail subject to legal action. I reserve the right to publicly post or ridicule any abusive E-mail. Reply to domain Patriot dot net user shmuel+news to contact me. Do not === Subject: Re: quaternions > what is the point of quaternions? > they are all the square root of -1. the only thing of interest about > them is their relationships among each other... completely arbitrary > to me. There are more things in heaven and earth, Horatio, than are dreamt of in your philosophy. === Subject: Re: quaternions >what is the point of quaternions? >they are all the square root of -1. the only thing of interest about >them is their relationships among each other... completely arbitrary >to me. There was a thread last year, quaternions-- whats the point?, that might be helpful. I saved the following therefrom: >Did you try a Google search on quaternions? The fourth entry I found was >how to use them for representing rotations - including a explanation of one >advantage quaternions have over other representations. If you look at >http://www.j3d.org/faq/manipulating.html#quaternions youll get an idea of >why quaternions are part of Java 3D. === Subject: Re: quaternions >>what is the point of quaternions? >>they are all the square root of -1. the only thing of interest about >>them is their relationships among each other... completely arbitrary >>to me. ... > There was a thread last year, quaternions-- whats the point?, that > might be helpful. I saved the following therefrom: >>Did you try a Google search on quaternions? The fourth entry I found was >>you how to use them for representing rotations - including a explanation >>of one >>advantage quaternions have over other representations. While the use of quaternions in representing rotations is no doubt a valuable tool, I wouldnt say it is the most important application. The quaternions H form the only non-commutative division algebra (or skew-field) of finite dimension over the reals R. As such they are likely to arise in any context where R or the complex numbers C arise. For example, every simple group representation of finite degree over C is associated to R, C or H, with those associated to H corresponding to symplectic structures. This is a basic theme in the classification of simple Lie groups. -- Timothy Murphy e-mail (<80k only): tim /at/ birdsnest.maths.tcd.ie tel: +353-86-2336090, +353-1-2842366 s-mail: School of Mathematics, Trinity College, Dublin 2, Ireland === Subject: Re: quaternions >what is the point of quaternions? >they are all the square root of -1. the only thing of interest about >them is their relationships among each other... completely arbitrary >to me. What is the point of your question? Just a bunch of letters in the english alphabet... completely arbitrary to me. G. Rodrigues === Subject: Re: quaternions >what is the point of quaternions? >they are all the square root of -1. the only thing of interest about >them is their relationships among each other... completely arbitrary >to me. > What is the point of your question? Just a bunch of letters in the > english alphabet... completely arbitrary to me. > G. Rodrigues point of my question was that i didnt know much about quaternions and was curious what they are used for.. all i knew was the basic relations. comments about algebras and rotations of spaces lead me in just the right directions to do the research i was looking to do. what was the point of your statement? just to look like an idiot? it seems as though both our points were well taken. yours by me and mine by everyone but you. stuff that one up your stocking till christmas 2008 buddy :) === Subject: Re: quaternions >>what is the point of quaternions? >>they are all the square root of -1. the only thing of interest about >>them is their relationships among each other... completely arbitrary >>to me. >> What is the point of your question? Just a bunch of letters in the >> english alphabet... completely arbitrary to me. >> G. Rodrigues >point of my question was that i didnt know much about quaternions and >was curious what they are used for.. all i knew was the basic >relations. comments about algebras and rotations of spaces lead me in >just the right directions to do the research i was looking to do. >what was the point of your statement? just to look like an idiot? it >seems as though both our points were well taken. yours by me and mine >by everyone but you. It is always sad when one has to point out the meaning of his own words, but the point of my irony was that you framed your question in a trollish manner and as such you deserved a trollish answer. But probably its just me getting hyper-sensitive. G. Rodrigues === Subject: Re: quaternions >> >>what is the point of quaternions? >>they are all the square root of -1. the only thing of interest about >>them is their relationships among each other... completely arbitrary >>to me. >> >> What is the point of your question? Just a bunch of letters in the >> english alphabet... completely arbitrary to me. >> >> G. Rodrigues >point of my question was that i didnt know much about quaternions and >was curious what they are used for.. all i knew was the basic >relations. comments about algebras and rotations of spaces lead me in >just the right directions to do the research i was looking to do. >what was the point of your statement? just to look like an idiot? it >seems as though both our points were well taken. yours by me and mine >by everyone but you. > It is always sad when one has to point out the meaning of his own > words, but the point of my irony was that you framed your question in > a trollish manner and as such you deserved a trollish answer. > But probably its just me getting hyper-sensitive. > G. Rodrigues i didnt need to point out the meaning of my words. i got good answers before i ever pointed out the meaning to you. it is always sad when someone is such an old grouch that hes set in his obnoxious ways and cant find a way out of them (like taking any legitimate question to be a trolling) get a grip man. besides, who cares if you ARE hyper sensitive? grouch around these groups for awhile longer and maybe youll be able to discern between trolls and nontrolls. judging from your comments.. that would rate as a worthwhile expenditure of your time.. to you. === Subject: Re: quaternions days. My association with the Department is that of an alumnus. >what is the point of quaternions? Just like complex numbers can be used to model the rotations/contractions of the plane about the origin, the quaternions give the rotations and contractions of 3-dimensional space. >they are all the square root of -1. the only thing of interest about >them is their relationships among each other... completely arbitrary >to me. No; as Hamilton explained when he introduced them, the relation ij=-ji, (ij)^2=-1 has to do with their geometric interpretation. -- Its not denial. Im just very selective about what I accept as reality. --- Calvin (Calvin and Hobbes) Arturo Magidin magidin@math.berkeley.edu === Subject: Re: Proof of the Full Beal Conjecture posting-account=i3V6Cw0AAADtbYn3XKL9H7v2PfvxgaVa doh! Old post on beal conjecture. Sorry, but if anyone knows about the beal conjecture status any news would be helpful. > Did you ever get any feed back on the Beal Conjecture thing? > The beal conjecture website (www.bealconjecture.com) still shows the > prize money as available. I just wonder if you have heard from Beal > about his Conjecture. Has anyone solved the beal conjecture? > Or has anyone disproved the beal conjecture. > Is fermats last theorem and the Beal conjecture the same thing? > I have recently uploaded my proof of the Beal Conjecture. It may be > downloaded from its listing under the Fermats Last Theorem > category > on the Open Directory Project. > It is also available directly at- geocities.com/kerrymerry2000. === Subject: Re: Proof of the Full Beal Conjecture conjecture award is still not paid out. If you didnt notice the date, I doubt you have much chance of proving or disproving the beal conjecture. Try something easier like the lottery. > doh! > Old post on beal conjecture. > Sorry, but if anyone knows about the beal conjecture status any news > would be helpful. >> Did you ever get any feed back on the Beal Conjecture thing? >> The beal conjecture website (www.bealconjecture.com) still shows the >> prize money as available. I just wonder if you have heard from Beal >> about his Conjecture. Has anyone solved the beal conjecture? >> Or has anyone disproved the beal conjecture. >> Is fermats last theorem and the Beal conjecture the same thing? >> I have recently uploaded my proof of the Beal Conjecture. It may > be >> downloaded from its listing under the Fermats Last Theorem >> category >> on the Open Directory Project. >> It is also available directly at- geocities.com/kerrymerry2000. === Subject: Re: =?ISO-8859-1?Q?Automatic_generation_of_G=F6del_sentence?= > |It sounds as though Emanuel has been reading _Goedel,_Escher,_Bach_. > |Hofstatders exposition of this point is at best confusing; while > |I cant put my hands on my copy to check what he actually said, I > |think its probably fair to say that Hofstatder just got it wrong. > My copy is not too deeply buried in boxes, but from what I remember, > he talks vaguely about our ability to Goedelize. This makes it sound > like it might be a question of generating Goedel sentences for systems. > But really hes talking about generating a sequence of theories like > PA, PA+con(PA), PA+con(PA+con(PA)),.... Call PA T, and call > PA+con(PA) T2, and so on. This sequence can be extended to > ordinal numbers given by suitable ordinal notations. The union > of T, T2, T3, T4,... can be axiomatized and we could call it > T_omega where omega is the first infinite ordinal. (I think > Hofstadter mentions this.) And we can keep going, letting > T_{omega+1} be T_omega+con(T_omega) and so on. > The problem with our ability to carry this on out is not with our > ability to generate con(T) for a theory T, but with our ability to > name ordinals (using ordinal notations). I think he just fails to > make this explicit. > Keith Ramsay > P.S. The original poster should be aware that the time has not > yet come to include ISO-8859 characters in subject lines. For > me this still displays the o as =F6. Patience, patience.... Well, Hofstadters exposition is a little dated, and as you can tell from the prizes it got, too literary for a mathematicians liking. Anyhow, there ought to be more interesting statements than consistency statements. There are a lot of undecidable statements for any given FAS. (And really I dont think the logical POV doesnt matter as much as many people think it does...) -- Eray Ozkural === Subject: Re: =?ISO-8859-1?Q?Automatic_generation_of_G=F6del_sentence?= |Well, Hofstadters exposition is a little dated, and as you can tell |from the prizes it got, too literary for a mathematicians liking. I disagree. Not all mathematicians like literariness but some do. I also wouldnt call it highly literary, Pulitzer prize or no Pulitzer prize. Its not what I would choose as a textbook for teaching Goedels theorem, but it is an entertaining popularization. It came out when I was at just the right age to appreciate it. |Anyhow, there ought to be more interesting statements than consistency |statements. There certainly should, but the diagonal argument is one of the easiest methods of proving independence, and it tends to exhibit similar-looking examples of independent statements. Its also somewhat adaptable. Given a property of sentences U(S) definable in the system, it describes how to cook up a sentence G such that G<->~U(G). So if you think that U(S) is sufficient to guarantee the truth of S, then you think G is true, but you dont think so because you think U(G) holds! When philosophers of mathematics get started talking about criteria for acceptance of axioms, I sometimes start to get this disturbing sense that they are on their way to providing a notion that could be arithmetized, and then turned into a conjecture: the consequences of the axioms that satisfy their criteria for axiom-acceptability should be true. But if it is so, it is not possible to prove from axioms satisfying their criteria. The criteria for acceptability of axioms can include such uncomputable things as their consistency with other axioms, being simpler than any other axioms having the same theorems and so on, having a lot of consequences by some criterion of a lot, and this situation still remains. Keith Ramsay === Subject: Limits in topologies, limits of topologies (categories anyone?) Im sure I came across this somewhere on the net sometime, but I cant for the life of me find it (not that Im lazy, I have tried (both to find it on the internet, and to figure it out myself)). Or perhaps this is just an exercise in (my) ignorance. In any event, heres a question I would like to understand the answer to: Simply put, is there any particularly nice way that anyone knows of to make (direct) limits in categories like limits in analysis/topology? Or more concretely, Im asking about the following: You have the notion of the direct limit in categories, which gives the direct limit of topologies in the category of topologies. And the direct limit of topologies is very similar in definition to the limit of nets - but is there any way of building a category around a particular topology so that the limit of a net *is* some direct limit in the category? (in this sense either a topological clarification (linking direct limits of topologies to direct limits in topologies) or a categorical clarification (just giving a topology the appropriate categorical structure) would completely answer my question) === Subject: Triple Coincidence With help from I.M. Davidson, Keith A. Lewis, Phil Carmody, Daniel W. Johnson, Gerry Myerson, Brian Quincy Hutchings, Stan Liu, Saint Cad, Jose Carlos Santos, and Richard Miller, I have been exploring the triple coincidence associated with FLT in threads Perky People Prefer Pseudorandom Periodicity, A fairly simple proposition, Counterexample to t((c^n - a^n) mod b) | phi(b), and On the Euler phi values of pairwise coprimer a,b, and c. The triple co-incidence derivable from a^n + b^n = c^n is (a^n + b^n) == 0 mod c & (c^n - a^n) == 0 mod b & (c^n - b^n) == 0 mod a. These three conditions are necessary but not sufficient for a^n + b^n = c^n. I call (a^n + b^n) mod c a dual additive exponential congruential generator, and (c^n - a^n) mod b a dual subtractive exponential congruential generator, and (c^n - b^n) mod a the same. Each generator has an associated congruential sequence ordered by n and these sequences are purely periodic with period dividing the phi of their corresponding bases, c, b, and a. For all a, b, and c, and n=0 the values of the three generators are 2, 0, and 0. At n = 1 the values are (mod c) unknown (can be 2), (mod b) nonzero, and (mod a) nonzero. At n = 2 the values are unknown (symbolically, so far). What is of interest in searches is that the only time the locations of the individual coincidences are all three the same is when they occur all at n = 2. Larger values for the coincidence are associated with at least one sequence having a period that differs from the other two. This implies that it might be possible to prove that for the triple coincidence to occur, it must happen either at 2 or at composite n. And we know from relatively elementary argument that n is prime, or at least that if there is a solution for composite n, there will be an associated solution for a prime n. 2 is the only prime that fits. So I am looking for any knowledge any of you readers may have, or references to knowledge of the periods of dual exponential congruential sequences. I thank you for your time. This is going to be all I have, I think, until after we close our apartment deal. Its rather stressful. On the other hand, its pretty much in the bag now. On the other other hand, the anticipation is just driving me up the wall. Closing is Wednesday, 24 Nov at 12:00. I tolerance everything and tolerate everyone. I love: Dona, Jeff, Kim, Kimmie, Mom, Neelix, Tasha, and Teri, alphabetically. I drive: A double-step Thunderbolt with 657% range. I fight terrorism by: Using less gasoline. === Subject: Re: meta-proof that p is not np Hi Torkel, It sounds as if you have not read the referenced theorems in Prof. Caludes paper, which is only a click away from you. If you would please read that, we can discuss the relevance of the referenced theorem. I have a complaint about your posting behavior. You ask a question. I give you an answer. You dont like the answer, or you do not read it. You rephrase exactly the same question and ask it. After you do this four times, people like me become demotivated, because this looks like an attempt to indoctrinate your ideas about indefinite things: philosophical questions like What on earth is reasoning?. Please read and respond to my answers, if you are asking questions. Otherwise, do not ask them. Here _we_ give a specific answer to your query from the viewpoint of digital philosophy. If you dont like digital philosophy. Fine. Then say, I dont accept this, because I think X. But do explain your position as we do. The question you have asked the second time is answered in response to your question once more. Please take the time to think about it. > Take any bit of Omega, there is no way to know _in general_ this > single bit of information from something else, in the sense of > computing it from something, or more mathematically speaking > proving it from some axioms (which are not distinct things, of > course). > There is indeed no computational procedure which proves all true > statements of the form the n-th bit of Omega is i. The same is true > of any undecidable set of true statements - nothing special about > Omega here. What I am asking about is the claim that statements > of the form the n-th bit of Omega is i are true for no reason > and can only be postulated, not proved. > That is, we are basing our argument on Chaitins version of Godelian > incompleteness. We say that no (finite) formal axiomatic system can > ever settle arbitrarily many bits of Omega. > And how does this fact imply that the truth of a statement of the > form the n-th bit of Omega is i can only be postulated, not arrived > at by reasoning? If COMPUTATIONAL=REASONING, then the answer is clear, Torkel. Chaitin implicitly assumes that MIND=COMPUTATION, but I doubt he is aware of his own assumption. So, you are right in a sense. Hes making certain metaphysical assumptions. And he does not make the effort to make these clear. Its not top-notch philosophy at all. Now, here is the question to you. In your opinion, is the mind a discrete computation? Or is it something over and above discrete computation? Let all the other discussion suspend until you answer this. If you will answer, I will be more than glad to discuss this matter with you, a prominent scholar who is humble enough to write on sci.math Looking forward to hearing from you. -- Eray Ozkural miserable phd student === Subject: Re: meta-proof that p is not np > You rephrase exactly the same question and ask it. After you do this > four times, people like me become demotivated, Well done Torkel! I was wondering how to do that :-) -- Robin Chapman, www.maths.ex.ac.uk/~rjc/rjc.html Lacan, Jacques, 79, 91-92; mistakes his penis for a square root, 88-9 Francis Wheen, _How Mumbo-Jumbo Conquered the World_ === Subject: Re: meta-proof that p is not np > I have a complaint about your posting behavior. You ask a question. I > give you an answer. Nothing in your answer is anything to the point. === Subject: Re: meta-proof that p is not np > I have a complaint about your posting behavior. You ask a question. I > give you an answer. > Nothing in your answer is anything to the point. Well, you seem to have reading comprehension problem. I said. If mind is a computation, the philosophical conclusions follow easily. Do you agree that mind is a computation or not? Please answer this simple question. -- Eray === Subject: Ozkural solves mind-body problem was Re: meta-proof that p is not np > I said. If mind is a computation, the philosophical conclusions follow > easily. > Do you agree that mind is a computation or not? Ônuff said! -- Robin Chapman, www.maths.ex.ac.uk/~rjc/rjc.html Lacan, Jacques, 79, 91-92; mistakes his penis for a square root, 88-9 Francis Wheen, _How Mumbo-Jumbo Conquered the World_ === Subject: Re: Ozkural solves mind-body problem was Re: meta-proof that p is not np > I said. If mind is a computation, the philosophical conclusions follow > easily. Do you agree that mind is a computation or not? > Ônuff said! You better attribute that to Stan Lee - you copyright violator! === Subject: Re: Ozkural solves mind-body problem was Re: meta-proof that p is not np > I said. If mind is a computation, the philosophical conclusions follow > easily. Do you agree that mind is a computation or not? Well, I am not even the last to suggest that the mind may be a computation. However, in the above quote, I am not asserting that the computational view of the mind is correct. (Although I think so) Again, you are misrepresenting my quotes. Try to read my sentences more carefully. The claim is this: Chaitin seems to be implicitly presupposing the correctness of computationalism. On such a premise, the other philosophical claims about no reason trivially follow. Torkel might not be able to see that. So, here is a challenge for Torkel. If the mind is a computation, then no reason has a very precise mental meaning, and indeed Omega is not amenable to any reason in such a possible world. You have to accept its bits as brute facts about the world if youre unfortunate enough to occupy such a world. Regardless of whether our world is like that, do you agree with this answer? -- Eray Ozkural === Subject: Re: Ozkural solves mind-body problem was Re: meta-proof that p is not np >> Eray are there integers with an infinite number of digits? Ozkural >> I said. If mind is a computation, the philosophical conclusions follow >> easily. >> >> Do you agree that mind is a computation or not? > Well, I am not even the last to suggest that the mind may be a > computation. > However, in the above quote, I am not asserting that the computational > view of the mind is correct. (Although I think so) Again, you are > misrepresenting my quotes. Try to read my sentences more carefully. What would be the point in that? Is there any reason to read your sentences at all? -- Robin Chapman, www.maths.ex.ac.uk/~rjc/rjc.html Lacan, Jacques, 79, 91-92; mistakes his penis for a square root, 88-9 Francis Wheen, _How Mumbo-Jumbo Conquered the World_ === Subject: Re: meta-proof that p is not np > I said. If mind is a computation, the philosophical conclusions > follow easily. Nothing in what you have said is anything to the point. === Subject: Re: meta-proof that p is not np > I said. If mind is a computation, the philosophical conclusions > follow easily. > Nothing in what you have said is anything to the point. You seem to have a reading problem. 1. If mind is computation, then reasoning too is mere computation 2. Hence any truth that cannot be ascertained by mere computation, as is the case with the problem of determining an arbitrary number of bits of Omega, is impenetrable to reason. 3. Hence, we say they are true for no reason. There is no deeper reason to why they are what they are. The individual bits are brute facts of the world, which must be accepted without reasoning. Cannot you understand such a simple argument? Here is the complete answer to your question, and you cannot understand it. True for no reason if reason is computation. Chaitin seems to assume this. You probably do not agree with it, because you sound like some sort of vitalist, or religious person. You probably believe mind is not computational, but has some kind of logical existence distinct from the physical. I wouldnt be surprised if you believed in such a silly thing. Prove me wrong. -- Eray === Subject: Re: meta-proof that p is not np > 1. If mind is computation, then reasoning too is mere computation > 2. Hence any truth that cannot be ascertained by mere computation, > as is the case with the problem of determining an arbitrary number of > bits of Omega, is impenetrable to reason. Whats supposed to be special about Omega in this argument? === Subject: Re: meta-proof that p is not np > Do you agree that mind is a computation or not? What is a mind? People have been slicing a dicing other people for 10,000 years and no one has ever found a mind in a body he didnt own. There are brains, glands and other gooey and s Please answer this simple question. Bob Kolker === Subject: Re: meta-proof that p is not np Do you agree that mind is a computation or not? > What is a mind? People have been slicing a dicing other people for > 10,000 years and no one has ever found a mind in a body he didnt own. That may be because minds are not things to be found in a body you do not own. Or perhaps because we dont have the proper technology to find minds. I dont know the answer. You are basically asking the problem of other minds. Are you familiar with philosophy of mind? This is a question with no definite answer. There are *answers*, none of which is conclusive. But the best answer seems to be computational, for what its worth. Its easy to work out one. To see another mind, you would have to become part of the same computation, which only occurs to a small extent using language. So the answer of computationalism is that you do *see* other minds every day, only in a very limited fashion due to architectural limits. You see them through computation, not by opening up their brains and looking at them! There are some versions of computationalism, the most famous is Putnams machine functionalism which he abandoned later to retreat into some ancient myst. (claiming that we need a theory of direct perception, yes...) (Note that I dont favor Putnams brand of computationalism. His theories do not seem physically plausible) > There are brains, glands and other gooey and s Nobody claimed that there are no brains. But claiming that there are NO MINDS is quite naive. Consider the problem of qualia. You can try to get rid of qualia by denying that it exists. But that is seen as a poor way of argumentation. (Worse if you say minds do not exist. That is actually the claim of David Longleys brand of radical behaviorism. Beware!) Because its similar to this imaginery tale. There is an obvious phenomenon called light. Suppose that we didnt have a good theory of light, we couldnt really explain how all the rainbows, refractions, etc. occured, but these things, however magical looking, occured, it is certain that there is a physical phenomenon. Now, philosophers in this world of poor science may try this route: light does not exist. How realistic is that? The challenge of contemporary philosophy of mind is the challenge of explaining the mind-body problem and other fundamental issues (like the problem of qualia) satisfactorily well from the point of view of physicalism. These things exist, and they are physical (like light), what is their nature? Is there a universal theory of mind, etc.? (Or for instance, is mind always a particular type of thing, like the minds realized by biological brains, etc.) We cannot really accept any form of substance dualism, and that is definitely not what Im suggesting. However, you just *cant* turn your back to the harsh reality of subjective experience. We cant yet explain what it is, but we think it is worth explaining. We might even lack the necessary conceptual framework entirely. My suggestion is that we should try an alternative metaphysics, lets forget Platonism. I think if we can explain computation, we can explain subjective experience, too. But I dont think we can explain computation well enough. A basic problem is this. There is something to being you. But most philosophers think there is nothing to being a glass. Why this difference? Ive worked on the above problems of subjective experience and qualia, and I think I have come to an interesting answer through modern theory of computation and information theory that does not seem to be limited to narrow content. A more metaphysical version of this theory is called Multism, and you can find its synopsis on comp.ai.philosophy and elsewhere. (There is also the Multism of Plamen Petrov, which is similar but not the same) It seems substance monism inherent in my Multism theory and mechanical irreducibility can easily answer what qualia is. In particular, there is digital multism, which tries to give more specific answers under the digital postulate. It goes like this, there is an irreducible essence to the computation that occurs in your brain. This irreducible essence defines the extent of your subjective experience, and with every bit you take out of this essence you would become less you, until when we reduced your essence to nothing, there would be nothing left to being you. This is quite physicalist, as you can imagine. However, it says the *quality* of a mental state is best explained by the information theoretic properties of the computation. And it suggests that the solution should be somewhere between radical reductionism (basically any idea that wants to reduce us to nothing) and radical nonreductionism (Quine). I have not yet made my mind about supporting multiple realizability, but I think at one level, we will have to accept a form of multiple realizability. Obviously, I can transfer one idea from this bubble of subjective experience to another by tapping on keys. So, thats quite remarkable. It means ideas can be multiply realized. Why not for greater constructs like complete mental states then? Maybe, subjective experience changes, but other properties remain the same, which is sufficient for multiple realizability (So here again, I think we need to make some compromises to arrive at a solution) -- Eray Ozkural === Subject: Fermat 420 Fermats Last Theorem Ben Ito 11-19-04 I will show that Fermats n=4 and Wiles proofs are invalid then prove Fermats last theorem. l. Introduction Fermats last theorem states that A^n + B^n = C^n, (equ 1) when n>2 does not form integer solutions of A, B and C. 2. Fermats n=4 Proof Fermats n=4 proof is described. Fermat uses the integer solution equations of n=2, A = 2uv, B = u^2 - v^2, and C = u^2 + v^2 (equ 2), to derive, A^2 = 2uv, B^2 = u^2 - v^2, and C = u^2 + v^2 (equ 3a,b,c), (Shanks, p.141). Equations 3a,b,c are used to prove that n=4 does not form integer solutions. Fermats proof is only proving equations 3a,b,c do not form integer solutions. Equations 3a,b,c are derived from n=2 integer solution equations (equ 2a,b,c); therefore, Fermats proof violates logic. 3. Wiles Proof Wiles proof of FLT uses Fermats elliptic curve. The elliptic curve equation is derived using the integer solution equations of n=2 (Osserman, p.21), a = (m^2 - n^2), b = 2mn, c = (m^2 + n^2). (equ 3) The elliptic curve is only valid for n=2; therefore, Wiles proof of FLT is invalid since Wiles proof is using Fermats elliptic curve. 4. Proof of FLT. I will prove Fermats last equation using the pattern formed by the solutions formed by n=1 and n=2. Using n=1 in equation 1, X + Y = Z (equ 4) All integers of equation 4 form solutions. An integer solution set occurs at (1,2,3). The integer solutions of n=2 are described with the following equations, X = 2uv, Y = u^2 - v^2 and Z = u^2 + v^2 (equ 5) Not all integers form integer solutions for n=2. An integer solution set occurs at (3,4,5). The n=1 and n=2 solutions show a pattern where solutions are formed when a solution set is forms close to the origin, n=1 --> (1,2,3) and n=2 --> (3,4,5). In addition, when n=1, the strength of the solution set formation is maximum since all integers form solutions. When n=2, not all integers form solutions; therefore, the strength of the solution formation is weakening. When n=3, the solution set is weakening as n increases and the solution set is not formed close to the origin; consequently, the integer sequence ends at n = 3. Therefore, only n=1 and n=2 form integer solutions. 5. Conclusion Fermats n=4 proof uses equations derived from the integer solutions equation of n=2 to prove that n=4 does not form integers; therefore, Fermats n=4 proof violates logic. Fermats elliptic curves are derived using the integer solution equations of n=2; therefore, an elliptic curve can not be used to prove FLT when n>2. I will prove FLT by showing a pattern forms from the n=1 and n=2 solution sets which indicates that only n=1 and n=2 form integer solution sets. 6. References Robert Osserman. Fermats Last Theorem (a supplement to the video). MSRI. 1994 Daniel Shanks. Solved and Unsolved Problems in Number Theory. Chelsea Pub. 1985. *-----------------------* www.GroupSrv.com *-----------------------* === Subject: (probably stupid) question on Fermat decidability I was reading Simon Singhs book on Fermats last theorem, and got a big confused by one passage - he mentions the possibility that the theorem was undecidable (although obviously it turned out not to be). What confused me was this: The theorem couldnt be false but undecidable, since falsehood implies the existance of a definite counter-example. So if its undecidable then it must be true, which contradicts it being undecidable. So you get a contradiction, therefore it cannot be undecidable. Would anyone care to point out where Im going wrong here? === Subject: Re: (probably stupid) question on Fermat decidability . So if its undecidable then it must be true, which > contradicts it being undecidable. So you get a contradiction, > therefore it cannot be undecidable. > Would anyone care to point out where Im going wrong here? The word undecidable is a translation of unentscheidbare, thus the undecidability must be Goedels undecidability that is, formal undemonstrability within a system of axioms. A counterexample is not a formal demosntration. If Goldbachs conjecture is shown undecidable within accepted arthmetic, a counterexample will not take off its Goedels undecidability. === Subject: Re: (probably stupid) question on Fermat decidability > . So if its undecidable then it must be true, which >> contradicts it being undecidable. So you get a contradiction, >> therefore it cannot be undecidable. >> Would anyone care to point out where Im going wrong here? > The word undecidable is a translation of unentscheidbare, thus the > undecidability must be Goedels undecidability that is, formal > undemonstrability > within a system of axioms. A counterexample is not a formal > demosntration. Huh? A counter example is most definitely a formal demonstration that something is false. If somebody shows me that 15^235 + 126^235 = 127^235 That establishes that FLT is untrue. Nothing informal about that. > If Goldbachs conjecture is shown undecidable within accepted > arthmetic, a counterexample will not take off its Goedels > undecidability. Oh yes it will. If you can find a counter example, it is definitely decidable (in the negative, as it turns out). And if you have shown that it is undecidable within accepted arithmetic, and you can use accepted arithmetic to show it is false, then you proved accepted arithmetic is inconsistent, at which point most of mathematics as we know it disaapears in a puff of smoke ... === Subject: Re: (probably stupid) question on Fermat decidability In sci.math, Peter Webb <41a17fea$0$20521$afc38c87@news.optusnet.com.au>: >> . So if its undecidable then it must be true, which > contradicts it being undecidable. So you get a contradiction, > therefore it cannot be undecidable. > Would anyone care to point out where Im going wrong here? >> The word undecidable is a translation of unentscheidbare, thus the >> undecidability must be Goedels undecidability that is, formal >> undemonstrability >> within a system of axioms. A counterexample is not a formal >> demosntration. > Huh? > A counter example is most definitely a formal demonstration that something > is false. > If somebody shows me that > 15^235 + 126^235 = 127^235 > That establishes that FLT is untrue. Sorry, cant oblige. 15^235 + 126^235 - 127^235 = -2090269352984120073921722601405239849756 98701156813977808530086497347643268855835153351409895379215712 70545556 96047113642907266161896490603848988223386752695909209616202863 73126245 79003191791437569316475219065598456749706850464082308913917438 62001266 14584142281680681711860394371540275476446763248337752289071905 08149387 62305958339298913102809397702883908437833507352734231665434920 08228388 76298259266359220806875535614140466167947509312461332307198356 85424633 75358215282629964552579522143894992 :-) [rest snipped] -- #191, ewill3@earthlink.net Its still legal to go .sigless. === Subject: Re: (probably stupid) question on Fermat decidability === Subject: Re: (probably stupid) question on Fermat decidability >The theorem couldnt be false but >undecidable, since falsehood implies the existance of a definite >counter-example. Yes, it couldnt be false but undecidable. In logic, but means and. The theorem could be false, undecidable *or* true. It is true. I tolerance everything and tolerate everyone. I love: Dona, Jeff, Kim, Kimmie, Mom, Neelix, Tasha, and Teri, alphabetically. I drive: A double-step Thunderbolt with 657% range. I fight terrorism by: Using less gasoline. === Subject: Re: (probably stupid) question on Fermat decidability > Yes, it couldnt be false but undecidable. What do you mean by undecidable? === Subject: Re: (probably stupid) question on Fermat decidability > Yes, it couldnt be false but undecidable. > What do you mean by undecidable? Undecidable means there cannot exist a formal proof of a theorems true/false status. How to prove undecidability is beyond me. But I know you cant, in general, prove a negative, that is, that nobody had proven FLT until Wiles et al proved it certainly did not establish the undecidability of FLT. That no proof of something exists isnt proof no proof can exist. Exhaustive search of possible proofs is as futile as exhaustive search of quadruples n,a,b,c, looking for a counterexample to FLT. You never run out. Wiles proof reached beyond the axioms of number theory, didnt it? Number theory is what Goedel (spelling?) undecidability is about, isnt it? Anybody? Doug === Subject: Re: (probably stupid) question on Fermat decidability > How to prove undecidability is beyond me. The consensus seems to be that you cant (in this case at least); if you did prove FLT to be unprovable then youd generate a contradiction (because that would in turn prove it true). Is this generally true of all theorems? === Subject: Re: (probably stupid) question on Fermat decidability days. My association with the Department is that of an alumnus. >> How to prove undecidability is beyond me. >The consensus seems to be that you cant (in this case at least); if >you did prove FLT to be unprovable then youd generate a contradiction >(because that would in turn prove it true). You are mistaken. There would be no contradiction. If something like, say, Goldbachs Conjecture (a better example than FLT since FLT is know proven) were shown to be formally undecidable in, say, Peano Arithmetic, this would not generate any contradiction, but it would be possible to state that Goldbachs Conjecture will necessarily be true in the standard model (because a counterexample would be verifiable). >Is this generally true of all theorems? The same conclusion (undecidable in the system -> true in the standard model) holds for statements of the specific kind like FLT or Goldbach, where if they were false, then there would be a verifiable counterexample. -- Its not denial. Im just very selective about what I accept as reality. --- Calvin (Calvin and Hobbes) Arturo Magidin magidin@math.berkeley.edu === Subject: Re: (probably stupid) question on Fermat decidability > The same conclusion (undecidable in the system -> true in the > standard model) holds for statements of the specific kind like FLT or > Goldbach, where if they were false, then there would be a verifiable > counterexample. No!! Either one of A or ~A, where A is a formally undecidable statement within a model, can be added as an axiom to that model to form a new and larger model which remains consistent. If, for example, A is the Goldbach conjecture, then adding ~A to the model for arithmetic as it is generally understood does not lead to a contradiction. All it says is that a counterexample can not be found by any finite number of steps within the model which omits the axiom. Lets see if a simpler example would help. Within the natural numbers, consider the statement there is no natural number x such that x*x=2. Lets pretend for the sake of illustration that it is formally undecidable and then add it as an axiom that there exists an x such that x*x=2. A completely consistent theory is the result. The new theory includes the theory of natural numbers as a sub-theory (and all true derivable theorems within that model would remain derivable in the larger model), but there is still no *natural* number x such that x*x=2 which can be found by any finite number of deductions from the Peano axioms. Its a subtle point, perhaps, but a formal system and an interpretation of a formal system are very different things. In the example given, one can no longer interpret a variable x as a natural number but is forced to interpret it as an irrational number, which contains the interpretation as a natural number as merely a special case. Also as the example shows, adding underivable statements as axioms can lead to interesting mathematics. Paul -- Hanging on in quiet desperation is the English way. The time is gone, the song is over. Thought Id something more to say. === Subject: Re: (probably stupid) question on Fermat decidability >> The same conclusion (undecidable in the system -> true in the >> standard model) holds for statements of the specific kind like FLT or >> Goldbach, where if they were false, then there would be a verifiable >> counterexample. >No!! >Either one of A or ~A, where A is a formally undecidable statement >within a model, can be added as an axiom to that model to form a new >and larger model which remains consistent. Yes. > If, for example, A is the >Goldbach conjecture, then adding ~A to the model for arithmetic as it >is generally understood does not lead to a contradiction. You did notice the point where I said standard model? The model we would get by adjoining ~A would contain non-standard integers. >All it says >is that a counterexample can not be found by any finite number of >steps within the model which omits the axiom. You did notice I explicitly said standard model, right? IF Goldbachs conjecture were undecidable in Peano Arithmetic, then the fact you mention (that a counterexample cannot be found by any finite number of steps within the model which omits the axioms) would establish that, in the ->standard model<-, Goldbachs conjecture would be true. When we adjoing the negation to obtain a larger axiom system, the standard model is no longer a model for this enriched system. The rest of what you said seemed right to me. Yes, I am aware that if you have a formally undecidable proposition relative to an axiom system, you may add either the sentence or its negation to the axiom system and obtain a new consistent system. [.rest deleted.] -- Its not denial. Im just very selective about what I accept as reality. --- Calvin (Calvin and Hobbes) Arturo Magidin magidin@math.berkeley.edu === Subject: Re: (probably stupid) question on Fermat decidability > Undecidable means there cannot exist a formal proof of a theorems > true/false status. There is no such concept in logic. === Subject: Re: (probably stupid) question on Fermat decidability : I was reading Simon Singhs book on Fermats last theorem, and got a : big confused by one passage - he mentions the possibility that the : theorem was undecidable (although obviously it turned out not to be). : What confused me was this: The theorem couldnt be false but : undecidable, since falsehood implies the existance of a definite : counter-example. So if its undecidable then it must be true, which : contradicts it being undecidable. So you get a contradiction, : therefore it cannot be undecidable. : Would anyone care to point out where Im going wrong here? There is a difference between truth in an absolute system, and decidability (synonymous with provability in this context) in a first-order axiom system. See an old post of mine http://www.math.niu.edu/~rusin/known-math/97/goedel for a more detailed discussion. Usually decidability refers to a first-order axiom system, where as truth in the Ôabsolute natural numbers is defined by a second-order set of axioms. So a given statement could be true in the natural numbres (provable by second-order axioms that define the natural numbers) but not decidable (provable by the first-order axioms we are working with). Ted === Subject: Re: (probably stupid) question on Fermat decidability >I was reading Simon Singhs book on Fermats last theorem, and got a >big confused by one passage - he mentions the possibility that the >theorem was undecidable (although obviously it turned out not to be). >What confused me was this: The theorem couldnt be false but >undecidable, since falsehood implies the existance of a definite >counter-example. So if its undecidable then it must be true, which >contradicts it being undecidable. So you get a contradiction, >therefore it cannot be undecidable. >Would anyone care to point out where Im going wrong here? If you could prove that FLT was undecidable, that would prove it true, which would actually be a contradiction. But saying it might be undecideable and proving that it definitely is are 2 different things. Finding a counterexample would have proven it false. But not finding a counterexample doesnt prove it non-false unless you have checked all possibilities, which for FLT are infinite. --Keith Lewis klewis {at} mitre.org The above may not (yet) represent the opinions of my employer. === Subject: Re: (probably stupid) question on Fermat decidability days. My association with the Department is that of an alumnus. >>I was reading Simon Singhs book on Fermats last theorem, and got a >>big confused by one passage - he mentions the possibility that the >>theorem was undecidable (although obviously it turned out not to be). >>What confused me was this: The theorem couldnt be false but >>undecidable, since falsehood implies the existance of a definite >>counter-example. So if its undecidable then it must be true, which >>contradicts it being undecidable. So you get a contradiction, >>therefore it cannot be undecidable. >>Would anyone care to point out where Im going wrong here? >If you could prove that FLT was undecidable, that would prove it true, which >would actually be a contradiction. No. Because undecidable should really be formally undecidable; the proof that it is true (in the standard model based on the fact that it is formally undecidable) is not formalizable within the model, so there is no contradiction. -- Its not denial. Im just very selective about what I accept as reality. --- Calvin (Calvin and Hobbes) Arturo Magidin magidin@math.berkeley.edu === Subject: Re: (probably stupid) question on Fermat decidability > If you could prove that FLT was undecidable, What do you mean by undecidable? === Subject: Re: (probably stupid) question on Fermat decidability > I was reading Simon Singhs book on Fermats last theorem, and got a > big confused by one passage - he mentions the possibility that the > theorem was undecidable (although obviously it turned out not to be). > What confused me was this: The theorem couldnt be false but > undecidable, since falsehood implies the existance of a definite > counter-example. So if its undecidable then it must be true, which > contradicts it being undecidable. So you get a contradiction, > therefore it cannot be undecidable. In what way does that contradict it being undecidable? > Would anyone care to point out where Im going wrong here? The Goedel sentence is an example of a statement that is true but unproveable (hence undecidable) within the system under consideration. -- Dave Seaman Judge Yohns mistakes revealed in Mumia Abu-Jamal ruling. === Subject: Re: Is this question fair for statistics class? by support1.mathforum.org (8.11.6/8.11.6/The Math Forum, $Revision: 1.9 primary) id iAJNXxR30254; You pose an interesting question and raise others implicitly. Regarding the one you pose, it is of course unfair to ask a question requiring knowledge not given or pointed to in class or homework assignments; but is that indeed what happened? I sure see a difference between no correlation and curvilinear correlation; and given that choice and the data points shown I must agree with your instructors evaluation of your response - totally incorrect. I find some correlation so strongly evident that I probably would have queried the instructor before saying the data were so chaotic that no correlation existed. Look, think; maybe ask if unsure. What did the instructor say about the deduction after the test was returned to you? Did you consult her in a private office visit, in a confrontational manner in class, or not at all? I would surely suggest diplomacy as a first response rather than the somewhat emotional outburst revealed in your post. Why are you so concerned that she offers advantages not on the syllabus? I would see such surprises (dropping lowest score) as pleasant developments rather than opportunities to criticize the syllabus! If she said it in class, she couldnt be lying - not with all those witnesses! Finally, if you KNEW she has done the same thing in years past, why hadnt THE WORD gotten out? You can bet that where I went to college, everyones answer would be tailored in advance to be exactly what she wanted to see, down to the last semicolon!! These comments are offered, not to stand up for another college math teacher, but rather to suggest that cooling off and learning what you can (statistics and otherwise) from the experience will serve you well in the long run. I simply do not know both sides of the story, but sense that nurturing your displeasure will only escalate a conßict best forgotten. >i got -20 from a test http://www.johncho.us/ stat.jpg , because i put zero >correlation instead of curvilinear correlation, we did not study >curvilinear correlations and such. >I think it is unfair to put it on the test. Nearly every student got it >wrong. >Furthermore, every year that she has put it on the test students have >gotten it wrong; that just tells me that she is not telling students the >truth about things and rather going around the truth hoping that students >find it. >she said she drops the lowest test, but it does not say that on her syllbus >i cannot believe she did this === Subject: Re: Why Do Americans Call It Math? by support1.mathforum.org (8.11.6/8.11.6/The Math Forum, $Revision: 1.9 primary) id iAJNY0e30265; >If an American pronouce it like British people, >do you think hes snobbish? > If an American pronounced schedule like the BritÇs he would be speaking correct English! If a Brit pronounced it like an American he would be considered uneducated. === Subject: Re: Why Do Americans Call It Math? at 11:34 PM, jm.drew@ntlworld.com (John Drew) said: >If an American pronounced schedule like the Brit s he would be >speaking correct English! If a Brit pronounced it like an American he >would be considered uneducated. I find the statement ironic, considering the context. I might consider you uneducated for not knowing that Usenet is an ASCII medium and that header indicates an appropriate character set and encoding, e.g., Presumably you meant to write Brits. -- Shmuel (Seymour J.) Metz, SysProg and JOAT Unsolicited bulk E-mail subject to legal action. I reserve the right to publicly post or ridicule any abusive E-mail. Reply to domain Patriot dot net user shmuel+news to contact me. Do not === Subject: Re: Why Do Americans Call It Math? I used to say Maths, as a Brit, I still do sometimes in the UK, but I gave putting the s on the end makes it awkward to lisp out. Math avoids the horrible triple consonant Ôths Math or Mathematics is easier to say... one has to bow to simplicity Richard Miller >If an American pronouce it like British people, >do you think hes snobbish? > If an American pronounced schedule like the BritÇs he would be speaking correct English! If a Brit pronounced it like an American he would be considered uneducated. === Subject: Re: Why Do Americans Call It Math? >>
How do you pronounce schedule?
>>If an American pronouce it like British people,
>>do you think hes snobbish?
>>
If an American pronounced schedule like the BritÇs he would be speaking correct English! If a Brit pronounced it like an American he would be considered uneducated. There is a story of how Dorothy Parker was at a party, and an American there who had just returned from London was talking airily about his experience, dropping names and Brittishisms, including go on and on about the tube schedule, pronouncing the second word as the British do. Ms. Parker found this unbearably pretentious, and finally leaned over to him and said in a loud whisper, I think youre full of skit. -- Mark Thornquist === Subject: Schwartzneleaticus Paradox The Schwartzneleaticus Paradox presented here of course constitutes a proof by reduction to the absurd that SR is nonsense, but SR undoubtedly has a way of Ôcooking the books to convince themselves the absurd is a fact of nature. It is named in part for Melvin Schwarts because of something really stupid he said in his excellent (as far as I can tell) book, Principles of Electrodynamics, available from those horrible promulgators of historical foundations, Dover Publications. In the book he argued that there could be no contraction transverse to the line of movement because if identical twins collided upright at high speed John could see Jims head plow into his belly, and Jim could see Johns head plow into his belly. The argument was fine as is but ignored the obvious, which perhaps I posted here sometime or other: let two identical boxers pass each other at high velocity, Ôeast and Ôwest, both with their heads to the Ôeast and feet to the Ôwest and each facing a direction that would allow them to throw a straight punch at the other when their feet are coincident. John would see his fist pass over Jims head and Jims fist plow into his belly, but Jim would see his fist pass over Johns head and Johns fist plow into his belly. Schwartz was absolutely correct that his gedanken experiment disproved transverse contraction, and the obvious extention has proved parallel contraction absurd. There is a way to remove the necessity of punch throwing in the paradox (reduction to the absurd of SR). Let identical twins approach each other at high speed, gamma = 2.1 or so, each with their heads in the Ôeast and feet in the Ôwest along the direction of movement, and both tilted somewhat to the Ônorth side of the direction of movement. Let their feet collide. John feels Jims head crash into his testicles and Jim feels Johns head crash into his testicles. Ouch! Not just for John and Jim but for SR, which is thus shown to be nonsense and proved invalid by reduction to the absurd. SR is consistent? You betcha! Consistent idioocy! eleaticus === Subject: Re: Schwartzneleaticus Paradox > The Schwartzneleaticus Paradox presented here of course constitutes a > proof by reduction to the absurd that SR is nonsense, but SR undoubtedly has > a way of Ôcooking the books to convince themselves the absurd is a fact of > nature. > It is named in part for Melvin Schwarts because of something really stupid > he said in his excellent (as far as I can tell) book, Principles of > Electrodynamics, available from those horrible promulgators of historical > foundations, Dover Publications. > In the book he argued that there could be no contraction transverse to the > line of movement because if identical twins collided upright at high speed > John could see Jims head plow into his belly, and Jim could see Johns head > plow into his belly. > The argument was fine as is but ignored the obvious, which perhaps I posted > here sometime or other: let two identical boxers pass each other at high > velocity, Ôeast and Ôwest, both with their heads to the Ôeast and feet to > the Ôwest and each facing a direction that would allow them to throw a > straight punch at the other when their feet are coincident. John would see > his fist pass over Jims head and Jims fist plow into his belly, but Jim > would see his fist pass over Johns head and Johns fist plow into his > belly. > Schwartz was absolutely correct that his gedanken experiment disproved > transverse contraction, and the obvious extention has proved parallel > contraction absurd. > There is a way to remove the necessity of punch throwing in the paradox > (reduction to the absurd of SR). > Let identical twins approach each other at high speed, gamma = 2.1 or so, > each with their heads in the Ôeast and feet in the Ôwest along the > direction of movement, and both tilted somewhat to the Ônorth side of the > direction of movement. Let their feet collide. John feels Jims head crash > into his testicles and Jim feels Johns head crash into his testicles. > Ouch! Not just for John and Jim but for SR, which is thus shown to be > nonsense and proved invalid by reduction to the absurd. > SR is consistent? Yes, it is consistent. Your example assumes that simultaneity is absolute; which is inconsistent with SR. You have assumed your conclusion, which is falacious. One other thing that is consistent is your intense stupidity. ROS has been pointed out to you many times before, but your pathetic little mind is incapable of learning. Paul Cardinale === Subject: Re: Schwartzneleaticus Paradox SR is consistent? > Yes, it is consistent. > Your example assumes that simultaneity is absolute; which is > inconsistent with SR. You have assumed your conclusion, which is > falacious. Why go so far out of your way to prove your corrupt cretinism? Non-absolute simultaneity has no utility when discussing human sized objects in impact. If you think it does, then make it ant sized objects. What a cretin you are! eleaticus > One other thing that is consistent is your intense stupidity. ROS has > been pointed out to you many times before, but your pathetic little > mind is incapable of learning. > Paul Cardinale === Subject: Re: Schwartzneleaticus Paradox >> SR is consistent? >> Yes, it is consistent. >> Your example assumes that simultaneity is absolute; which is >> inconsistent with SR. You have assumed your conclusion, which is >> falacious. >Why go so far out of your way to prove your corrupt cretinism? >Non-absolute simultaneity has no utility when discussing human sized objects >in impact. If you think it does, then make it ant sized objects. >What a cretin you are! Non-absolute simultaniety applies to any object, however small, provided the impact is sufficiently rapid that the time scale is comparable to the time it takes for light to travel along the object. John Savard http://home.ecn.ab.ca/~jsavard/index.html === Subject: Re: Schwartzneleaticus Paradox SR is consistent? > Yes, it is consistent. > Your example assumes that simultaneity is absolute; which is > inconsistent with SR. You have assumed your conclusion, which is > falacious. > Why go so far out of your way to prove your corrupt cretinism? > Non-absolute simultaneity has no utility when discussing human sized objects > in impact. If you think it does, then make it ant sized objects. > What a cretin you are! Jeezzuss! Non absolute simultaneity doesnt have to have utility to explain SR for any size objects. Can you even define utility in the context that you introduced the term into this discussion. SR predicts non absolute simultaneity and predicts how to relate measurements made in different frames of reference using relativity of simultaneity. If you think that you can disprove this, then show us an experiment that does so. And dont just claim that it hasnt been done at some particular scale. John Anderson === Subject: Viewpoint and Schwartzneleaticus Paradox > Non-absolute simultaneity has no utility when discussing human sized objects > in impact. If you think it does, then make it ant sized objects. > What a cretin you are! > Jeezzuss! Non absolute simultaneity doesnt have to have utility > to explain SR for any size objects. Can you even define utility > in the context that you introduced the term into this discussion. > SR predicts non absolute simultaneity and predicts how to relate > measurements made in different frames of reference using relativity > of simultaneity. Both are hoizontal Ôheight .0000000000000000000000000000000000000866 approx. A feet start at time t=t=0 by convention and at x=-.866 approx, x=--1.732 approx. A feet start at time t=t=0 by convention and at x=0. Their relative velocity is .866c approx and gamma = 2.. Their feet become adjacent at t=1, at which time the A head is at .0000000000000000000000000000000000000866 , the lower abdomen of A, gamma being 2. So far there is unmistakable simultaneity, being strictly from viewpoint A. location zero and the A head is at .0000000000000000000000000000000000000433, the location of the A belly. That being from an unmistakable simultaneity viewpoint, being strictly from viewpoint A. Hence, boxer A fist misses the A head but he sees the A fist plow into his belly. And hence, boxer A fist misses the A head but he sees the A first plow into his belly. QED If you are half my height, our feet are adjacent, and our heads extend in the same direction, your head is just above my crotch, no matter what time it is. And SR says that is the situation in the given setup at my time t=1. If I am half your height, our feet are adjacent, and our heads extend in the same direction, my head is just at the lower parta of your belly no matter what time it is. And SR says that is the situation in the given setup at your time t=1. Wait a minute! That is direct application of SR. But dont you know that SR is so ed up that the direct application of its basic equations is tacitly outlawed by the SR-cult? You are not allowed to use those basic equations directly. To do so shows them to be complete nonsense, invalid by reduction to the absurd, as above. So, lets play the True Believer SR-cult cretin game and pretend SR isnt crap, and that the non-simulataneity isnt the most vomitous version of the crap. No, lets dont. Why practice their idiocy? The given resolution being absolutely irrefutable given SR-contraction, any further SR-idiocy that says otherwise is proof by reduction to the absurd that SR is crap. Whats the problem, over and above the basic problem that SR is crap? Screwed up viewpoint. We know that the contraction result of x=gx-gvt is not the moving system viewpoint, it is supposedly what A will see, not what A will see for itself. A does not see himself contracted according to SR-dogma. Too bad, because if he saw himself as contracted the .866 distance would be 1.732 for him and at v=.866 the feet would become adjacent at t=2, the same figure the SR-idiot A would calculate for t. We also know that A doesnt see A as contracted: let a rail run from adjacent to the A feet to adjacent to the A feet, to mark the distance with something physical. The rail would be only .433 long and at v=.866 it would be at time t=.5 that the feet were adjacent, not the t=2 the SR-idiot A calculated using SR, not the t=1 an actual A would see it taking. We know that the dilation result of (the corrupt) t=gt-gxt/cc is not the moving system viewpoint, it is supposdedly what A will see, not what A will see for itself. A does not see himself slowed down. No Ôtoo bad here because there is no way the (mis)info can be used. With t=d/v, what in hell would it mean to say time has slowed? Nothing! No consequence. That is, not just x and t but also x and t are stationary system viewpoints, one pair sane, and the other pair pure psychotic idiocy. In our setup, the moving system also see that it takes t=1 elapsed time unit to become feet-adjacent. The moving system sees at that time that - given contraction - the A head is at the A belly. Period. The idiocy of the BEER (Basic Equations of Einsteins Relativity) has nothing to do with the moving system measures, it is nonsense, crap, and ... well, SR. eleaticus === Subject: Re: Schwartzneleaticus Paradox > The Schwartzneleaticus Paradox presented here of course constitutes a > proof by reduction to the absurd that SR is nonsense, [snip crap] eleaticus, Oren Webster, is a despised and stooopid troll, http://users.pandora.be/vdmoortel/dirk/Physics/Fumbles/ Crimes.html Several crimes against logic and science Ha ha ha! Originally trolled across sci.physics sci.physics.relativity alt.physics sci.math sci.answers alt.answers news.answers Psychotic ineducable boring troll Eleaticus, Were there to be internal inconsistencies in SR (meaning inconsistencies of a purely mathematical logical nature) that would automatically lead to contradictions in number theory, itself, and arithmetic, since the mathematics of Minkowski geometry is equiconsistent with the theory of real numbers and with arithmetic. Eleaticus explicitly demonstrates that he is completely ignorant of multivariable calculus. He has no concept of the Chain Rule in multivariable calculus. Consider his Galilean Transformation goo and dribble: t = t, x = x - vt, y = y, z = z. His refusal to accept that t must be introduced as a separate variable springs from a massive emprical stupidity re space and time are described as a four-dimensional manifold, with four coordinates instead of a time evolution of a three-dimensional manifold, and that the change of coordinate system should be a change of four coordinates, and not a time-dependent change of three coordinates. This is particularly vital when it comes to fields over space and time (electric and magnetic fields for example). The transformation law for the differential operators under the Galilean transformation is given by: d/dt = d/dt + v d/dx, d/dx = d/dx, d/dy = d/dy, d/dz = d/dz. This shows the necessity of introducing a new variable t, since partial differentiation with respect to t (constant x, y, z) is a different operation to partial differentiation with respect to t (constant x, y, z). The above transformation law is determined by the Chain Rule: d/dt = dt/dt d/dt + dx/dt d/dx + dy/dt d/dy + dz/dt d/dz, d/dx = dt/dx d/dt + dx/dx d/dx + dy/dx d/dy + dz/dx d/dz, d/dy = dt/dy d/dt + dx/dy d/dx + dy/dy d/dy + dz/dy d/dz, d/dz = dt/dz d/dt + dx/dz d/dx + dy/dz d/dy + dz/dz d/dz. The presence of the term involving d/dx in the expression for d/dt is indicative of the fact that x depends on t (x, y, z, being held constant), as can be seen from the fact that the coefficient of d/dx in the expression for d/dt is dx/dt. Because of the now demonstrated fact that Eleaticus has no formal education in multivariable calculus, he has managed, somehow, to get it into his head that the presence of the term involving d/dx in the expression for d/dt is indicative of t depending on x (t, y, z, being held constant). Because of his stupidty Eleaticus cannot get the correct transformation law for the differential operators under the Galilean Transformation, and he cannot determine the invariance or otherwise of Maxwells Equations under the Galilean Transformation. The first advice to Eleaticus is to learn multivariable calculus. Eleaticus should not pretend that he can understand how to determine invariance or otherwise of Maxwells Equations under the Galilean Transformation, or under the Lorentz Transformation, until he understands the multivariable calculus which underlies such considerations. Eleaticus is a loud idiot. The homogeneous Maxwell equations are invariant under the Galilean Transformation, with transformation laws: E_x = E_x, E_y = E_y - v B_z, E_z = E_z + v B_y, B_x = B_x, B_y = B_y, B_z = B_z. The derivation of these transformation laws was determined using the transformation laws for the differential operators given above. These transformation laws have the additional advantage that they determine the correct transformation for the force law, thus providing further evidence in favour of the transformation law for the differential operators, as above. The inhomogeneous Maxwell equations are also invariant under the Galilean transformation, with transformation laws: E_x = E_x, E_y = E_y, E_z = E_z, B_x = B_x, B_y = B_y + v/c^2 E_z, B_z = B_z - v/c^2 E_y, rho = rho, J_x = J_x - v rho, J_y = J_y, J_z = J_z. Note the the transformation laws for the charge density and current density are as they should be under the Galilean transformation. Homogeneous equations are invariant under the Galilean Transformation, and inhomogeneous equations are invariant under the Galilean Transformation, but Maxwells Equations as a whole are NOT invariant under the Galilean Transformation, since the transformation laws required for the EM field for the two cases are inconsistent with each other. The transformation law for the EM field which makes the homogeneous equations invariant will not also make the inhomogeneous equations invariant. The transformation law for the EM field which makes the inhomogeneous equations invariant will not also make the homogeneous equations invariant. On the other hand, all of Maxwells equations are invariant under the Lorentz Transformation, with transformation laws: E_x = E_x, E_y = gamma (E_y - v B_z), E_z = gamma (E_z + v B_y), B_x = B_x, B_y = gamma (B_y + v/c^2 E_z), B_z = gamma (B_z - v/c^2 E_y), rho = gamma (rho - v/c^2 J_x), J_x = gamma (J_x - v rho), J_y = J_y, J_z = J_z, where gamma = 1/sqrt(1 - v^2/c^2). Idiot Oren Webster sees himself this way, http://www.mazepath.com/uncleal/effete6.jpg The entire remainder of the planet sees him this way, http://www.mazepath.com/uncleal/effete3.png http://www.mazepath.com/uncleal/sunshine.jpg http://www.apa.org/journals/psp/psp7761121.html http://insti.physics.sunysb.edu/~siegel/quack.html Hey, stooopid troll Eleaticus - Do you want EVIDENCE? Each of the 24 GPS satellites carries either four cesium atomic clocks or three rubidum atomic clocks in orbit, with full relativistic corrections being applied. Mathematics of gravitation Equivalence Principle testing http://arXiv.org/abs/hep-th/0111236 Geometric structure of reality http://arxiv.org/abs/gr-qc/0103044 http://arXiv.org/abs/hep-th/0307140 GR structure, especially Part 4/p. 7 http://arXiv.org/abs/gr-qc/0311039 Experimental constraints on General Relativity http://www.eftaylor.com/pub/projecta.pdf Relativity in the GPS system http://arXiv.org/abs/gr-qc/9909014 falling light Hafele-Keating Experiment http://www.hawaii.edu/suremath/SRtwinParadox.html Twin Paradox http://arXiv.org/abs/astro-ph/0401086 http://arxiv.org/abs/astro-ph/0312071 Deeply relativistic neutron star binaries http://arxiv.org/abs/hep-th/0405160 Black hole evaporation No aether http://fsweb.berry.edu/academic/mans/clane/ No Lorentz violation http://arXiv.org/abs/gr-qc/0409089 Spin-2 gravitons have problems (so does the proposal) http://arXiv.org/abs/gr-qc/0301024 Nordtvedt Effect NIM A 355 537 (1995) Physics Letters B 328 103 (1994) Physical Review Letters 64 1697 (1990) Physical Review Letters 39 1051 (1977) Physical Review 135 B1071 (1964) Physics Letters 12 260 (1964) Europhysics Letters 56(2) 170-174 (2001) General Relativity and Gravitation 34(9) 1371 (2002) http://fourmilab.to/etexts/einstein/specrel/specrel.pdf http://users.powernet.co.uk/bearsoft/Paper6.pdf http://users.powernet.co.uk/bearsoft/LPHrel.html Longitudinal and transverse mass http://www.navcen.uscg.gov/pubs/gps/gpsuser/gpsuser.pdf http://www.navcen.uscg.gov/pubs/gps/sigspec/default.htm http://www.navcen.uscg.gov/pubs/gps/icd200/default.htm http://www.trimble.com/gps/index.html http://sirius.chinalake.navy.mil/satpred/ http://www.phys.lsu.edu/mog/mog9/node9.html http://egtphysics.net/GPS/RelGPS.htm http://www.schriever.af.mil/gps/Current/current.oa1 http://edu-observatory.org/gps/gps_books.html -- Uncle Al http://www.mazepath.com/uncleal/ (Toxic URL! Unsafe for children and most mammals) http://www.mazepath.com/uncleal/qz.pdf === Subject: Uncle assAl: Troll House Kookie > eleaticus, Oren Webster, is a despised and stooopid troll, > Psychotic ineducable boring troll Eleaticus, You can buy your very own Uncle assAl (yuck!) at the bakery. Just ask for a TrollHouse Kookie. eleaticus === Subject: Re: Uncle assAl: Troll House Kookie > eleaticus, Oren Webster, is a despised and stooopid troll, > Psychotic ineducable boring troll Eleaticus, > You can buy your very own Uncle assAl (yuck!) at the bakery. > Just ask for a TrollHouse Kookie. > eleaticus I have added an appropriate little cartoon to that page: http://users.pandora.be/vdmoortel/dirk/Physics/Fumbles/ Crimes.html Hey Oren Coward Webster, how come you dont reply to ? Dirk Vdm === Subject: Fermat 420 Optica! Ben Ito 10-19-04 I will prove that the wave theory of light is invalid then prove that 1. Introduction which conßicts with Maxwells EM plane wave structure of light. The wave theory of light is justified with Huygens principle, Fresnels T&R equations, Maxwells structure of light, Plancks blackbox, Einsteins quanta, quantum mechanics, and QED. I will prove that the the wave effects of light. 2. Huygens Principle Huygens principle describes wave theories propagation, and aperture diffraction mechanisms of light. According to Huygens principle the energy of the source is re-create at interval of a wavelength, away from the source, which violate the law of conservation of energy. 3. Fresnels T&R Equations Fresnels T&R equations are derived using non-propagating plane waves. A propagating plane wave forms an average field effect of zero, at the glass surface; therefore, Fresnels derivation of the T&R equations uses non-propagating plane waves conßicts with the experimental propagation of light. 4. Maxwells Structure of Light Maxwells structure of light is derived from Maxwells (radio wave) equations. A continuous and dispersive field structure of an EM spherical wave is approximated with Maxwells plane wave. Therefore, conßicts with the photoelectric effect experiment. 5. Plancks Blackbox Emission Derivation Plancks blackbox emission derivation (1900) uses the standing waves of Maxwells structure of light (Eisberg, p. 15). However, light cannot physically form standing waves since the propagation of the plane wave cannot maintain the standing waves nodes at both surfaces. Standing waves are used to derive Plancks discrete energy equation. 6. Einsteins Quanta Einsteins photoelectric quanta equation derivation (1905) uses the work-dependent entropy equation (Nye, p. 470). However, the volume of Einstein system is constant; therefore, the change in entropy of Einsteins system is zero. Einstein derives the energy quanta equation using entropy equation. 7. Quantum Mechanics and QED Maxwells plane wave structure of light. However, a plane wave has an aperture, to the intensity areas of the diffraction pattern and does when the light contact the aperture edge does not aperture diffraction effect occur. 9. Conclusion Huygens principle describes a wave structure. A wave structure is then used by Fresnel to derive the T&R equations. Maxwells equations are used to derive an EM plane wave structure of light; which conßict with the experimental results of the photoelectric effect of light. Wave theory uses Plancks blackbox emission derivation, quantum structure; however, all these derivations use Maxwells structure of Einsteins photoelectric quanta equation derivation (1905) uses a gas however, Einsteins gas molecule analogy is inappropriate. The wave theory of light is a defense of Huygens principle. the intensity areas of the diffraction pattern, and does not allow 10. Books Robert Eisberg and Robert Resnick. Quantum Physics of Atoms, 1974. Dietrich Marcuse. Engineering Quantum Electrodynamics. Harcourt, Brace & World, Inc. 1970. Mary Jo Nye. The Question of the Atom. Tomash. 1984. *-----------------------* www.GroupSrv.com *-----------------------* === Subject: Finding unique sums. Im trying to find a series where the sum of a subset of that is unique. Or in other words, I can find the numbers from sum. An example would be f(n)=2^n, you add any number of elements in this set, youll get a number with all those bits set. But Im looking for a series that does not grow geometrically.. Pradeep === Subject: Re: Finding unique sums. > Im trying to find a series where the sum of a subset of that > is unique. Or in other words, I can find the numbers from sum. > An example would be f(n)=2^n, you add any number of elements > in this set, youll get a number with all those bits set. > But Im looking for a series that does not grow geometrically.. > Pradeep Something a bit different (not better) from the other answers given... How about the sequence 0.4142135623730950488016887242... 0.8284271247461900976033774484... 0.6568542494923801952067548968... 0.3137084989847603904135097936... 0.6274169979695207808270195873... 0.2548339959390415616540391747... 0.5096679918780831233080783494... .... (Puzzle - is the sequence dense in [0,1]? (The sequence is 2^(n + 1/2) mod 1).) Mike. === Subject: Re: Finding unique sums. > Im trying to find a series where the sum of a subset of that > is unique. Or in other words, I can find the numbers from sum. > An example would be f(n)=2^n, you add any number of elements > in this set, youll get a number with all those bits set. > But Im looking for a series that does not grow geometrically.. I was looking for a series which consists of positive integers which has this property. Is it helpful if the size of the subset is known? For example, the sum of random 10 elements of a series is given, is it possible to get the individual elements(I mean is there such a series of positive integers other that 2^n and doesnt grow exponentially)? === Subject: Re: Finding unique sums. >> Im trying to find a series where the sum of a subset of that >> is unique. Or in other words, I can find the numbers from sum. >> An example would be f(n)=2^n, you add any number of elements >> in this set, youll get a number with all those bits set. >> But Im looking for a series that does not grow geometrically.. >I was looking for a series which consists of positive integers >which has this property. This has already been answered. Since the 2^n series is the Ômost efficient such series, all other series must grow faster. >Is it helpful if the size of the subset is known? >For example, the sum of random 10 elements of a series is given, >is it possible to get the individual elements(I mean is there >such a series of positive integers other that 2^n and doesnt >grow exponentially)? I believe this doesnt really change the outcome. All size-10 subsets must produce a unique sum implies (with handwave) that all subsets must produce a unique sum, so your sequence is going to grow exponentially. You can probably do away with the handwave above, by showing that assuming the existence of two size-N+1 subsets with identical sum but no size-N subsets leasds to a contradiction. -- Patrick Hamlyn posting from Perth, Western Australia Windsurfing capital of the Southern Hemisphere Moderator: polyforms group (polyforms-subscribe@egroups.com) === Subject: Re: Finding unique sums. >> Im trying to find a series where the sum of a subset of that >> is unique. Or in other words, I can find the numbers from sum. >> An example would be f(n)=2^n, you add any number of elements >> in this set, youll get a number with all those bits set. >> But Im looking for a series that does not grow geometrically.. >I was looking for a series which consists of positive integers >which has this property. >Is it helpful if the size of the subset is known? >For example, the sum of random 10 elements of a series is given, >is it possible to get the individual elements(I mean is there >such a series of positive integers other that 2^n and doesnt >grow exponentially)? Knowing the number of elements as well as their sum adds some possibilities. For example, f(n)=1000000+2^(n-1). But the core problem is that for every number you add, the number of possible subsets doubles. In order for each combination of numbers to produce a sum different from all other combinations, there need to be 2^N possible sums, where N is the number of values which might be part of the sum. Is this for a magic trick? --Keith Lewis klewis {at} mitre.org The above may not (yet) represent the opinions of my employer. === Subject: Re: Finding unique sums. > Im trying to find a series where the sum of a subset of that > is unique. Or in other words, I can find the numbers from sum. > An example would be f(n)=2^n, you add any number of elements > in this set, youll get a number with all those bits set. > But Im looking for a series that does not grow geometrically.. What about f(n) = 1/2^n (or 1/a^n, where a >= 2)? Does that count? -- Christopher Heckman === Subject: Re: Finding unique sums. - Super-increasing sequences and knapsack problems A super-increasing sequence is a sequence of integers >= 1 in which each element is larger than the sum of all the preceding elements. Starting with 1 and aiming at the slowest growing rate you get 1, 2, 4, 8, ... . This is the only super-increasing sequence that allows any integer >= 1 to be represented as the sum of some of its elements. No proof given here; must be not too difficult. Because of the super-increasing property these representations are unique. One could ask: given a sheath (one-dimensional knapsack) of integer length N >= 1; given a set S of rods of integer lengths, their total length being >= N; determine what subsets of S exactly fit into the sheath, if any such subsets exist. This problem is known as the knapsack problem. In general it is an NP-hard problem, reason why it plays an important role in cryptography. If the lengths of the rods in S form a super-increasing sequence, then the knapsack problem can be solved at once; for cryptographic applications you need sequences that are much slower increasing than 2^n. The farther below 2^n, the better. The 2^n sequence is at the borderline between (A) representing all integers but not uniquely, and (B) representing not all integers, but uniquely if possible. Literature: Denning: Cryptography and Data Security. Addison-Wesley, 1982. ISBN 0-201-10150-5 >> Im trying to find a series where the sum of a subset of that >> is unique. Or in other words, I can find the numbers from sum. >> An example would be f(n)=2^n, you add any number of elements >> in this set, youll get a number with all those bits set. >> But Im looking for a series that does not grow geometrically.. >> >What about f(n) = 1/2^n (or 1/a^n, where a >= 2)? Does that count? > -- Christopher Heckman === Subject: Re: Finding unique sums. > Im trying to find a series where the sum of a subset of that > is unique. Or in other words, I can find the numbers from sum. > An example would be f(n)=2^n, you add any number of elements > in this set, youll get a number with all those bits set. > But Im looking for a series that does not grow geometrically.. > Pradeep How about ANY series of positive numbers where each term is greater than the sum of all those preceding it? Would that work? (Still grows fast, but not necessarily geometrically.) === Subject: Re: Finding unique sums. >> Im trying to find a series where the sum of a subset of that is unique. Or >> in other words, I can find the numbers from sum. >> An example would be f(n)=2^n, you add any number of elements in this set, >> youll get a number with all those bits set. But Im looking for a series >> that does not grow geometrically.. > How about ANY series of positive numbers where each term is greater than the > sum of all those preceding it? Would that work? (Still grows fast, but not > necessarily geometrically.) Actually, that is geometric. Say the first term is a_0. Then the second term is a_1 > a_0, the third term is a_2 > a_1 + a_0 > 2a_0, the fourth is a_3 > a_2 + a_1 + a_0 > 2a_0 + a_0 + a_0 = 4a_0, etc. Apply induction if you wish; the answer is a sequence bounded below by a constant multiple of a geometric sequence. -- Ryan Reich ryanr@uchicago.edu === Subject: Re: Finding unique sums. > >> >> Im trying to find a series where the sum of a subset of that is unique. Or >> in other words, I can find the numbers from sum. >> >> An example would be f(n)=2^n, you add any number of elements in this set, >> youll get a number with all those bits set. But Im looking for a series >> that does not grow geometrically.. > How about ANY series of positive numbers where each term is greater than the > sum of all those preceding it? Would that work? (Still grows fast, but not > necessarily geometrically.) > Actually, that is geometric. Say the first term is a_0. Then the second term > is a_1 > a_0, the third term is a_2 > a_1 + a_0 > 2a_0, the fourth is a_3 > a_2 > + a_1 + a_0 > 2a_0 + a_0 + a_0 = 4a_0, etc. Apply induction if you wish; the > answer is a sequence bounded below by a constant multiple of a geometric sequence. Oh ... I understood grow geometrically to mean than a[i+1]/a[i] was constant. Is that not right? === Subject: Re: Finding unique sums. > How about ANY series of positive numbers where each term is greater than the > sum of all those preceding it? Would that work? (Still grows fast, but not > necessarily geometrically.) Actually, that is geometric. Say the first term is a_0. Then the second term > is a_1 > a_0, the third term is a_2 > a_1 + a_0 > 2a_0, the fourth is a_3 > a_2 > + a_1 + a_0 > 2a_0 + a_0 + a_0 = 4a_0, etc. Apply induction if you wish; the > answer is a sequence bounded below by a constant multiple of a geometric sequence. > Oh ... I understood grow geometrically to mean than a[i+1]/a[i] was > constant. Is that not right? Youre right. Ryan appears to think that n!, 2^2^n and 2^n! grow geometrically. This is either a gross abuse of terminology, or just plain wrong. Phil -- ... one Marine noticed one of the prisoners was still breathing. A Marine can be heard saying on the pool footage provided to Reuters Television: Hes ing faking hes dead. He faking hes ing dead. The Marine then raises his riße and fires into the mans head. The pictures are too graphic for us to broadcast, Sites said. === Subject: Re: Finding unique sums. > >> How about ANY series of positive numbers where each term is greater >> than the sum of all those preceding it? Would that work? (Still grows >> fast, but not necessarily geometrically.) Actually, that is geometric. Say the first term is a_0. Then the second > term is a_1 > a_0, the third term is a_2 > a_1 + a_0 > 2a_0, the fourth > is a_3 > a_2 + a_1 + a_0 > 2a_0 + a_0 + a_0 = 4a_0, etc. Apply induction > if you wish; the answer is a sequence bounded below by a constant > multiple of a geometric sequence. >> Oh ... I understood grow geometrically to mean than a[i+1]/a[i] was >> constant. Is that not right? > Youre right. > Ryan appears to think that n!, 2^2^n and 2^n! grow geometrically. This is > either a gross abuse of terminology, or just plain wrong. > Phil Well, if you are trying to avoid geometric growth it is reasonable for me to expect you to be trying to avoid greater-than-geometric growth as well. I was thinking of this from an efficiency perspective. The original question seemed to me to desire such an answer, which is impossible, of course. Totally off-topic for the thread, but pertinent to the terminology: has anyone else read Orson Scott Cards Memory of Earth series (I think its called) and winced at the Overminds description of its memory layout? It says something like This made my memory grow geometrically, but that is not enough; it needed to be exponential. -- Ryan Reich ryanr@uchicago.edu === Subject: Re: Finding unique sums. > Im trying to find a series where the sum of a subset of that > is unique. Or in other words, I can find the numbers from sum. > An example would be f(n)=2^n, you add any number of elements > in this set, youll get a number with all those bits set. > But Im looking for a series that does not grow geometrically.. How about sqrt{p_n} where p_n is the n-th prime? -- Robin Chapman, www.maths.ex.ac.uk/~rjc/rjc.html Lacan, Jacques, 79, 91-92; mistakes his penis for a square root, 88-9 Francis Wheen, _How Mumbo-Jumbo Conquered the World_ === Subject: Re: Finding unique sums. > Im trying to find a series where the sum of a subset of that > is unique. Or in other words, I can find the numbers from sum. > An example would be f(n)=2^n, you add any number of elements > in this set, youll get a number with all those bits set. > But Im looking for a series that does not grow geometrically.. The series f(n)=2^n grows exponentially. And it is clearly the most efficient series with your desired property, since all sums can be made with the minimum of terms. Any other such series would therefore be less efficiently Ôpacked, and would grow at a greater rate. Allowing negative numbers would be one way to Ôbreak this argument. -- Patrick Hamlyn posting from Perth, Western Australia Windsurfing capital of the Southern Hemisphere Moderator: polyforms group (polyforms-subscribe@egroups.com) === Subject: Re: Finding unique sums. > Im trying to find a series where the sum of a subset of that > is unique. Or in other words, I can find the numbers from sum. > An example would be f(n)=2^n, you add any number of elements > in this set, youll get a number with all those bits set. > But Im looking for a series that does not grow geometrically.. 2^n should be the smallest such series, at least if you are dealing with non-negative integers. === Subject: Re: Finding unique sums. <419e97d2$1_1@news.unc.edu> Im trying to find a series where the sum of a subset of that >> is unique. Or in other words, I can find the numbers from sum. >> An example would be f(n)=2^n, you add any number of elements >> in this set, youll get a number with all those bits set. >> But Im looking for a series that does not grow geometrically.. >2^n should be the smallest such series, at least if you are dealing with >non-negative integers. If you remove that restriction, you could go the opposite way, f(n)=2^(-n). Then youd have a fraction between 0 and 1. In fact, x^(+-n) will work for any x >= 2. --Keith Lewis klewis {at} mitre.org The above may not (yet) represent the opinions of my employer. === Subject: Computability: Recovering Delta_0 from Sigma_1? > This question is necessarily vague, but is there a known way to > Ôrecover the set of all -primitive- recursive relations (Delta_0) > from the set of recursively enumerable relations (Sigma_1)? Going up > the arithmetical hierarchy is easy, going down not so. > Note: I use the convention that Delta_0 is the set of primitive > recursive relations, not the set of computable relations. In > particular Delta_0 is not equal to Delta_1. Either way, the resulting > hierarchies are the same everywhere except of course at Delta_0. I > posted a thread asking about this choice a while back, see Primitive > recursive vs recursive at the base of the arithmetical hierarchy. > Rex Butler Speaking of, are there any other non-trivial characterizations of the set of primitive recursive relations? Rex Butler === Subject: Re: strong induction But isnt that redundant, since I already have proven it as a base case?? Radu Vlad > Say you have a sequence {x_n} defined by: > x_1 = -3 > x_2 = 23 > x_3 = -45 > x_n = 7x_(n-2) - 6x_(n-3) for n>=4 > Prove that: > x_n = 2(-3)^n + 2^n + 1 for all positive integers n (*) > If you prove that the base cases n = 1,2,3 are true, then > you have to assume that the formula (*) is true in the following conditions, > if n=r, for all 1<=r<= k for some k>=3 (n, k are positive integers) > My question is why is it you have to assume its true for k>=3 and not just > for k>3, > since you already have proven its true for k=3. > Is it not sufficient to assume the formula is true for k>3??? > ...and what if - in the course of the proof - you have to > use the assumption that your statement holds for k=3...? > Pawel Gladki === Subject: Re: strong induction days. My association with the Department is that of an alumnus. [.reformartted to remove the top-posting.] >> Say you have a sequence {x_n} defined by: >> x_1 = -3 >> x_2 = 23 >> x_3 = -45 >> x_n = 7x_(n-2) - 6x_(n-3) for n>=4 >> Prove that: >> x_n = 2(-3)^n + 2^n + 1 for all positive integers n (*) >> If you prove that the base cases n = 1,2,3 are true, then >> you have to assume that the formula (*) is true in the following >conditions, >> if n=r, for all 1<=r<= k for some k>=3 (n, k are positive >integers) >> My question is why is it you have to assume its true for k>=3 and not >just >> for k>3, >> since you already have proven its true for k=3. >> Is it not sufficient to assume the formula is true for k>3??? >> ...and what if - in the course of the proof - you have to >> use the assumption that your statement holds for k=3...? >But isnt that redundant, since I already have proven it as a base case?? When doing strong induction, you dont have base cases, you have special cases. That is, cases where the general argument does not apply. Part of the confusion people seem to have between regular and strong induction comes from confusing these two. In strong induction, I think the pedagogically better way of doing the proof would be to do the general argument FIRST, and then do any necessary special cases second (if any are needed); while in regular induction we do the base case first and the inductive step second. In this case, you have two choices: you can either assume it is true for k>=3; or else assume it is true for k>3 AND use the fact that it is also true for k=3. They both amount to the same (since you have established k=3 as a special case), and it is easier to do the single assumption in the former. -- Its not denial. Im just very selective about what I accept as reality. --- Calvin (Calvin and Hobbes) Arturo Magidin magidin@math.berkeley.edu === Subject: Re: Help me for an idea about the equation below? THx > A*r+B*(r)^2+C*r=D > Differential equation above has bothered me for a long time. I need > help. > I think I need the process of dealing with the equation. Can someone > do me a favor? I would rather appreciate. (Another respondent overlooked the square at the first derivative and treated the equation as linear.) Let me guess: it is a model of motion of a mass-spring system at high speeds when the friction is proportional to the square of velocity. Warning: At a certain stage, we will run into a non-elementary integration problem; the old-school terminology considers it still solvable in quadratures, that is, leaving the integration problem unfinished and relying on the theoretical existence of the solution. The traditional procedure is: Observe that the independent variable (say t) is not showing, so at the first stage we seek a relation between r and r. (I just gave my engineering students a test where one of the equations was of this type, although not as difficult.) Set v = r; then by Chain Rule, r = dv/dt = (dv/dr) * (dr/dt) = v * (dv/dr). Into your equation: A * v * dv/dr + B * v^2 + C*r - D = 0 or (A * v) * dv + (B * v^2 + C*r - D) * dr = 0 becomes a first order ODE. It is not exact but has an integrating factor m = exp(2*B*r/A) and you are on your own. You obtain an ODE relating r and r (and a first integration constant); here the mess starts. === Subject: Re: Help me for an idea about the equation below? THx >A*r+B*(r)^2+C*r=D >Differential equation above has bothered me for a long time. I need >help. >I think I need the process of dealing with the equation. Can someone >do me a favor? I would rather appreciate. Learning how to do this is a significant portion of 3rd semester calculus, which you should take if youre really interested in this kind of math. Now for the abbreviated version. Differential equations usually wind up as an exponential added to a polynomial. In this case, by inspection, the polynomial is D/C, which has first and second derivatives equal to 0. The exponential part is of the form r = e^(ax) r = ae^(ax) r = a^2 * e^(ax) A*r+B*(r)^2+C*r=0 (A*a^2 + B*a + C)*e^(ax) = 0 Since e^(ax) is never 0, this becomes a quadratic equation in a. Youll usually get two roots, sometimes complex, call them a_1 and a_2. Since either of them will work, add exponentials for both of them to your polynomial, multiplied by constants. Then you have: r(x) = D/C + c_1 * e^(a_1 * x) + c_2 * e^(a_2 * x) To find c_1 and c_2, you need to apply boundary conditions. For example, if you know r(0)=10 and r(1)=5 you can substitute into the above equation twice and solve. But you didnt mention having any boundary conditions, so the answer contains two unconstrained constants. --Keith Lewis klewis {at} mitre.org The above may not (yet) represent the opinions of my employer. === Subject: Re: Find a suitable cylinder to fit on helix I thought about this some more and decided one could indeed finish the computation more or less automatically, without having to look at the graph of a function of 2 variables to find the minimum. > I have a bunch of point in 3D with known (x,y,z) coordiantes. > They form a 3-D helix structure in space. > I choose to minimize (ahem) the sum of the squares of the differences > between the square of the nominal radius of the cylinder and the squares > of the distances between the points and the central axis. (phew!) [Summary: Let E be this sum. For a fixed plane we can easily find the best cylinder with central axis perpendicular to that plane, and compute this best E in terms of nine parameters r_i, each computed from the coordinates of the projections of the points to the plane.] > where D = (-r3*r2^2-r5*r1^2+r3*r5*r0-r4^2*r0+2*r2*r4*r1). > Using these values in the expansion of E, I get the minimum value of E = > (-r5*r6^2*r0-r0*r8*r4^2+2*r3^2*r2*r7+2*r5^2*r1*r6+r5^2*r4^2+2 *r3*r5*r4^2 > -2*r2*r4*r6*r5-2*r1*r4*r7*r5+2*r3*r5*r1*r6-2*r3*r2*r6*r4-2*r1 *r4*r3*r7 > -r3^3*r5-2*r3^2*r5^2+r4^2*r3^2-r3*r5^3+2*r3*r2*r7*r5-r5*r8*r1 ^2-r3*r7^2*r0 > -r3*r8*r2^2+r7^2*r1^2+r6^2*r2^2-2*r1*r2*r7*r6+2*r8*r2*r4*r1+2 *r0*r4*r7*r6 > +r3*r5*r8*r0) / D [We still have to choose the optimal plane. Pick an orthonormal basis {u,v} and compute the r_i from them. Heres where it gets messy...] > This isnt too bad a calculation. Almost every plane includes a unit > vector which also lies in the xy plane, necessarily of the form > u = ( 2*a/(1+a^2), (1-a^2)/(1+a^2), 0 ) > for some a, and then the other unit vector perpendicular to it must > be of the form > v = ( (1-b^2)*(1-a^2)/(1+b^2)/(1+a^2), > -2*a*(1-b^2)/(1+b^2)/(1+a^2), -2*b/(1+b^2) ) > for some b. The coordinates (x,y) of the projected > points p are the dot products ( u.p, v.p ), so that the r_i > computed above will be fairly simple rational functions of a and b. > In principle, this amounts to just algebra: you need to solve the > equations dE/da = dE/db = 0, essentially a pair of polynomials in > a and b, which you can do with resultants or something. But I have > to say --- and this is hard for me as a person who loves complicated > algebraic problems -- that this is just too hard! I couldnt resist. Its actually a fun challenge to carry this out; one could even do it fairly mechanically. Heres a summary of the steps I used. > Lets try this with some random points on a random cylinder: > [.6638582964, -.1489534114, -.7999397803] etc. But I want to work with exact arithmetic, so I prefer to scale these to integers. On the other hand, there are practical reasons I want the integers to be small (see below), so I will round these off; for example, the first point will now be [66,-15,-80]. > We must compute e.g. r1 = sum x_i = sum (u.x_i) ; I get this is now (-3838*a+1840*(1-a^2))/(1+a^2) > and similar expressions for the other r_i. > Substitute all of them into the prior expression for E and you get, E becomes a ratio of two integral polynomials in a and b, each of total degree 24. The coefficients have up to 25 digits. Then the vanishing of the derivatives dE/da, dE/db is equivalent to a pair of integral polynomials in a and b, of total degree 47. Actually there are some powers of (1+a^2) and (1+b^2) which can be factored out, so the degrees and the sizes of the coefficients are somewhat lower. Now, I think it is still true that it is not productive to try to eliminate b (say) from these two equations to get one polynomial equation to solve in a alone. I have some terrific software for this sort of thing, and it gets nowhere after a night of number crunching. Ah, but I have some more tricks up my sleeve! It is fairly easy to carry out the elimination over a FINITE field. For all the primes p I tested, Magma was able to eliminate b from the pair of polyomials over the Galois field GF(p), taking just a couple of minutes for 100-digit primes p. In every case, the result of the elimination was a monic polynomial of degree 132 with coefficients in GF(p). (As I will explain in a moment, I could have arranged the degree to be much lower.) Now, if the elimination were carried out over the rationals, we would also end up with a single polynomial, which we could assume to be monic by dividing by the lead coefficient. This polynomial could be reduced to the corresponding polynomial over GF(p) for every prime p except the few which divide the denominator of a coefficient of the rational polynomial. In order to determine the rational polynomial, we use the Chinese Remainder Theorem to find an integral polynomial which has the right reduction to each of the mod-p polynomials found. This can be done in seconds, even when the primes are a hundred digits long. The resulting integer polynomial has the property that each of its coefficients is congruent, modulo each of the primes p which I used, to the actual rational coefficient which we seek. In other words, we have found a large composite modulus N and an integer M < N with the property that M = z/x mod N for some (hopefully small) integers x and z. This is equivalent to the Diophantine equation M x + N y - 1 z = 0, where M,N (and -1 !) are known and x,y,z are sought. There certainly exist solutions; indeed, the set of all solutions is the integer lattice spanned by [ 1,0,M ] and [ 0,1,N ]. But we expect the right [x,y,z] to be some linear combination of these which is a much smaller vector in the Euclidean sense. (Just how small do I expect [x,y,z] to be? Thats not clear, although since M and N will be of comparable size, so should x and y be. So however large x and z are, we can reapply the previous construction to enough primes p, or to sufficiently large p, so that M and N are much larger than x,y,z; indeed [x,y,z] is likely to be the unique (up to sign) smallest vector in this lattice, as long as M and N are large enough. Taking what I hoped was a safe guess, I used 100 hundred-digit primes p, so that N had about 10,000 digits, and M was about as large. As long as x,y,z had only a few hundred digits each, the vector [x,y,z] would be very much smaller than any other vector in the lattice, except its own negative of course.) This circle of ideas would be useless if there were no way to FIND the smallest vector in a lattice, but in fact there is a now-well-known algorithm called LLL which does just that. (Actually it is only guaranteed to produce a pretty small vector, though not necessarily the very smallest, but it succeeds pretty well!) Magma can find the small vector almost instantly, and as it happens, finds a vector [x,y,z] whose entries have less than 400 digits each -- puny numbers! Applying this idea to each of the 133 coefficients in the monic integral polynomial, we obtain a monic rational polynomial whose coefficients are all small, and which still has the property that the rational polynomial reduces mod p to exactly the elimination polynomial we already found for each of these 100 large primes p. Having never won a lottery, we assume this cannot be dumb luck, and so we believe we have found the degree-132 polynomial in a which results from eliminating b from the pair of equations dE/da = dE/db = 0. Total time spent: about 1 hour. (Note that if I had retained more accuracy in the coordinates of my ten points, I would have correspondingly large integer values for the r_i, thus giving the polynomial equations dE/da = dE/db = 0 corresponding large integer equations. We thus expect the resultant of these two, w.r.t. b, to have larger integer coefficients too; x and z, above, will be larger, and thus the vector [x,y,z] will not stand out as the smallest vector in the lattice unles N and M are even larger. So I would have needed more than 100 hundred-digit primes to come to a conclusion if I had retained more accuracy in my points.) As further evidence that this is the right resultant polynomial, we observe that it has some special properties. It turns out to be a product (1+a^2)^15 * F1^3 * F2 where F1 has degree 12 and no real roots, and F2 has degree 66. In retrospect I could have tried factoring the mod-p polynomials first; had I noticed that there were always a few factors of high multiplicity, I might have Chinese-Remaindered my way back to the rational functions F1 and F2 separately, thus having only half as many coefficients -- smaller ones, no doubt -- to compute. Moreover, F1 and F2 are essentially unchanged under the substitution a -> -1/a, which we know is appropriate (that substitution corresponds to replacing the unit vector u with its antipode.) Our conclusion, then, is that there is a finite list of values of a which can be a coordinate of a critical point for the function E . We find these among the real roots of F2, of which there are ten: 0.04571164912, 0.2712828681, 0.2840536847, 0.4273887096, 0.7257134347 and the negatives of the reciprocals of these. Sure enough, for each of these there seem to be values of b making both dE/da=dE/db=0; again its just a matter of finding the roots of a polynomial. In each case there are two values of b which will serve, which are negative reciprocals of each other, i.e. the critical points of E come in sets of four ( (t,u), (t,-1/u), (-1/t,-u), and (-1/t,1/u) ). Representatives of the five sets are (a,b) = (0.0457116491, 3.1381940425) (0.2712828681, 0.3949015917) (0.2840536847, 0.4246190643) (0.4273887096, 0.5146083351) (0.7257134347, 0.3186546105) Once the general neighborhood of a critical point is known, one may use Maple to hunt for a solution to dE/da = dE/db = 0 nearby . > On the other hand, now that E is just a function of two variables > a and b, its easy to look at its graph e.g. with Maple. > I find, for example, > that there is a local minimum where a = 0.27, b=0.43 and E = 0.92. > However, the really interesting minima occur where > a = 0.42742, b=-3.11419 The actual location of the minimum has shifted around a bit since I have worked with a coarse rounding of the coordinates of the ten points, but this is fairly consistent with my present calculations; the difference is that now I dont have to look for the critical points, and I know I have a complete list of them. So I guess its a fairly reasonable project to locate the cylinder which minimizes E without resorting to looking at a graph to locate the minima. dave === Subject: Re: subseries of harmonic series converges iff ... >I recall reading a theorem once that says > For a subset S of Z+ , the following are equivalent: > * Sum_{s in S} 1/s < infty > * Something else. >Does anyone know what that something else is? I was hoping someone else would give the correct answer but I was under the impression theres a correct Something else of the form, * { x^s, s in S } is a basis for C[0,1] (the set of continuous functions on the interval). Or something like that. Its probably on my website but I cant figure out how to search for it! Erdos conjectured * {Something else} => {Sum_{s in S} 1/s < infty} (and offered a large prize for a proof). In this case Something else = There is an upper bound on the length of the arithmetic progressions in S. Golly, that sounds bad. The usual statement is the contrapositive of this. dave If you cant lead it to water or can make it drink, then its not a horse. === Subject: Re: subseries of harmonic series converges iff ... >I recall reading a theorem once that says > For a subset S of Z+ , the following are equivalent: > * Sum_{s in S} 1/s < infty > * Something else. >Does anyone know what that something else is? > I was hoping someone else would give the correct answer but I was > under the impression theres a correct Something else of the form, > * { x^s, s in S } is a basis for C[0,1] > (the set of continuous functions on the interval). Or something like that. This is the Muntz-Szasz theorem: If 0 < p1 < p2 < p3 < ..., then the span of {1, x^p1, x^p2, ...} is dense in C[0,1] iff 1/p1 + 1/p2 + ... = oo. (There is a nice proof of this in Rudins Real and Complex Analysis.) === Subject: Re: subseries of harmonic series converges iff ... in part: >I recall reading a theorem once that says > For a subset S of Z+ , the following are equivalent: > * Sum_{s in S} 1/s < infty > * Something else. Does anyone know what that something else is? I was hoping someone else would give the correct answer but I was > under the impression theres a correct Something else of the form, > * { x^s, s in S } is a basis for C[0,1] > (the set of continuous functions on the interval). Or something like that. > This is the Muntz-Szasz theorem: If 0 < p1 < p2 < p3 < ..., then the span > of {1, x^p1, x^p2, ...} is dense in C[0,1] iff 1/p1 + 1/p2 + ... = oo. > (There is a nice proof of this in Rudins Real and Complex Analysis.) Michael Hamm msh210@math.wustl.edu Standard disclaimers: http://math.wustl.edu/~msh210/ ... legal.html === Subject: Re: suggested free LaTex for windows > I am looking for a Latex editor for windows, which free ones are good out there. > thank you. The combination of MiKTeX and TeXnicCentre is nice (if by windows you mean Microsoft Windows). === Subject: Re: suggested free LaTex for windows > I am looking for a Latex editor for windows, which free ones are good out there. > thank you. I personally like to use plain old emacs, which is available for any common editor you might use under Linux/Unix will have a Windows port. (At least in the case of emacs you can even find versions that run on PDAs, which is pretty cool :) .) Lasse --- === Subject: Re: suggested free LaTex for windows > I am looking for a Latex editor for windows, which free ones are good out there. thank you. > I personally like to use plain old emacs, which is available for > any common editor you might use under Linux/Unix will have a Windows > port. (At least in the case of emacs you can even find versions that > run on PDAs, which is pretty cool :) .) > Lasse > --- yes, I use emacs under windows. Just like under unix/linux, it Ôunderstands .tex files. Ive found it fairly sufficient for basic editing. There is add-on tex mode with lots of bells and whistles, but I didnt bother to install it. Ive found it having the same editor for unix and windows is a Good Thing(TM). Like I use emacs/win to edit tex files at home, and emacs/Unix at school. === Subject: Re: suggested free LaTex for windows > yes, I use emacs under windows. Just like under unix/linux, it > Ôunderstands .tex files. Ive found it fairly sufficient for basic > editing. There is add-on tex mode with lots of bells and whistles, but > I didnt bother to install it. Its name is AucTeX and I think that its a great add-on. Jose Carlos Santos === Subject: Dynamic domain ? Im back once again, bloodied, but sincere. I have come to the conclusion that what I am doing is probably just stupidity, but I have resolved that if I am to engage myself in stupidity, then I might as well excell in it. So, I have refined my idiocy yet again, and here it is - --------------------------------- Example----------------- Given two physical objects in the physical universe, O1 and O2. Let O1 be a block of steel. Let O2 be a given quantity of heat energy. O1 and O2 are both unique physical objects. Now, combine O1 and O2 somehow to get O3, a warmer piece of steel. O1 and O2 no longer exist, and a brand new object O3 has come into existence. O3 is unique. End of example----------------- Discussion: It seems interesting that the property of uniqueness is preserved under the operation of combining the steel and the heat. The strange thing is that if you consider the operation of combining as a sort of operator, and if you consider your domain as all physical objects, then you have a domain which is not fixed. It is difficult maybe impossible to even define it formally. The question: I cant think of a single instance in math where you have an operator which performs upon a domain where your domain is so loose. The domain is dynamic ? New elements come into existence, and other elements cease to exist ? It just seems crazy. Ridiculous. Does anyone know of anything in mathematics where your domain is so changeable ? And the operator seems to control existence of elements in the domain ? It seems the exact opposite of any math Ive ever seen. Ordinarily, you define your domain, you have an operator(s), and this will yield groups, rings, fields, etc. But, this thing is crazy. The operator is controlling existence of elements within the domain. I dont know of any operators in math which can effect existence in the domain like this. It seems very odd. Any feedback ? === Subject: Re: Dynamic domain ? > Given two physical objects in the physical universe, O1 and O2. > Let O1 be a block of steel. > Let O2 be a given quantity of heat energy. O2 isnt an object. > O1 and O2 are both unique physical objects. > Now, combine O1 and O2 somehow to get O3, a warmer piece of steel. > O1 and O2 no longer exist, and a brand new object O3 has come into > existence. A block of warm steel is a block of steel is a block of cold steel. > O3 is unique. It is? After a while it cools and becomes O1. What happened to O2? > End of example I hope so. > Discussion: > It seems interesting that > The strange thing is > The question: > Any feedback ? Real farm feedback. Farmer feeds cows. Farmers wife feeds chickens. Farmers daughter milks cows and gathers eggs. === Subject: Re: Dynamic domain ? > Any feedback ? > Real farm feedback. > Farmer feeds cows. > Farmers wife feeds chickens. > Farmers daughter milks cows and gathers eggs. I could run with that, but ...... So, lets say you have an operator F, and a domain D. As elements of D are fed into F they cease to exist in D, and a completely new element for D is the result. I would have to say, this is a very strange F. I dont think that Ive ever seen such a thing as a function which does this to its own domain. Ever heard of anything like this ? === Subject: Re: Dynamic domain ? Farmer feeds cows. > Farmers wife feeds chickens. > Farmers daughter milks cows and gathers eggs. > I could run with that, but ...... dont run with the farmers daughter. > So, lets say you have an operator F, and a domain D. As elements of D are > fed into F they cease to exist in D, and a completely new element for D is > the result. > I would have to say, this is a very strange F. > I dont think that Ive ever seen such a thing as a function which does this > to its own domain. Ever heard of anything like this ? Live person is fed to death operator, ceases to exist. Now you new object, a dead body. US democracy is fed to Bushs operator, ceases to exist. Now you new object, a fascist state. === Subject: Re: Dynamic domain ? > Any feedback ? Real farm feedback. > Farmer feeds cows. > Farmers wife feeds chickens. > Farmers daughter milks cows and gathers eggs. > I could run with that, but ...... > dont run with the farmers daughter. > So, lets say you have an operator F, and a domain D. As elements of D are > fed into F they cease to exist in D, and a completely new element for D is > the result. > I would have to say, this is a very strange F. > I dont think that Ive ever seen such a thing as a function which does this > to its own domain. Ever heard of anything like this ? > Live person is fed to death operator, ceases to exist. > Now you new object, a dead body. > US democracy is fed to Bushs operator, ceases to exist. > Now you new object, a fascist state. Humor and math go very well together. Bushs war is killing people one at a time. It is arithmetic. Al Queda uses 1 assasin to kill hundreds. The killing is geometric. If I had to choose, I would choose no war at all. I love bears, and I love sharks. But if one was trying to eat me I would certainly try to kill it. War should always be the very last resort, but there is one option which might be even worse, and that would be surrendering yourself knowing that you will be killed without mercy. I dont have the answers to this problem. In fact, I once thought that I knew the answer to such a problem and the judge disagreed. They put me in the timecube (see www.timecube.com ) for a while, and now I generally try to avoid solving such problems because every possible solution is always wrong. Now Im just an illogical cubiq, and my math skills are isomorphic to the empty set. I am still wondering about operators which modify their own domains - Lefty TIMETRAVELLER and CUBIQ === Subject: Re: Dynamic domain ? Farmer feeds cows. > Farmers wife feeds chickens. > Farmers daughter milks cows and gathers eggs. > Bushs war is killing people one at a time. It is arithmetic. > Al Queda uses 1 assassin to kill hundreds. The killing is geometric. > If I had to choose, I would choose no war at all. I love bears, and I love > sharks. But if one was trying to eat me I would certainly try to kill it. > War should always be the very last resort, but there is one option which > might be even worse, and that would be surrendering yourself knowing that > you will be killed without mercy. > I dont have the answers to this problem. In fact, I once thought that I knew > the answer to such a problem and the judge disagreed. They put me in the > timecube (see www.timecube.com ) for a while, and now I generally try to > avoid solving such problems because every possible solution is always wrong. What problem? You stated none. You also didnt http://www.timecube.com so your reference not highlighting, wouldnt open. > Now Im just an illogical cubiq, and my math skills are isomorphic to the > empty set. I suggest you look sci.logic, thread logic is obsolete. In fact, sci.logic is a more appropriate location for your Ôobjective posts as also alt.math.recreational. > I am still wondering about operators which modify their own domains - Yes, tyrants. Bush for example, modifies his democratic domain into a theo-fascist domain. === Subject: Re: Dynamic domain ? > Now Im just an illogical cubiq, and my math skills are isomorphic to the > empty set. > I suggest you look sci.logic, thread logic is obsolete. > In fact, sci.logic is a more appropriate location for your > Ôobjective posts as also alt.math.recreational. They threw me out. Im a usenet refugee. > I am still wondering about operators which modify their own domains - > Yes, tyrants. Bush for example, modifies his democratic domain into > a theo-fascist domain. Well, I suppose that if birth and death are operators on living systems, then youd have a sort of _analogy_ of what Im talking about. Because, both birth and death modify the domain upon which they operate. They are like functions which create and also destroy elements in the domain. I dont think that there are any mathematical instruments which do this. I think that its very wierd, and Im trying to think of something more formal - but like I said - my math talents have converged to zero. Consider this algorithm - ----------------------------- 10 ÔStart with a finite set of numbers S 20 Select x1 at random from S 30 x2 = (x1)^2 40 Let x1 be deleted from S 50 Let x2 be joined to S 60 Select x3 at random from S 70 x4 = (x3)^(1/2) 80 Let x3 be deleted from S 90 Let x4 be joined to S 100 Goto 20 ------------------------------- Now, it might be equivalent to some type of recursive function, but whats the symbol for select at random ? Whats the symbol for delete from S ? Whats the symbol for join x1 to S ? I have never seen union and intersection operators used in a difference equation, or on the ßy. In fact, I dont think that any first order logical operators have ever been used dynamically - as one would construct coupled differential equations, or other recursive relations. I have never seen this. Have you ? Stephen Hawkings secretary wont put me through to him anymore. She just dumps me in his voicemail. I have to ask someone - === Subject: Re: Dynamic domain ? > Consider this algorithm - > ----------------------------- > 10 ÔStart with a finite set of numbers S > 20 Select x1 at random from S > 30 x2 = (x1)^2 > 40 Let x1 be deleted from S > 50 Let x2 be joined to S > 60 Select x3 at random from S > 70 x4 = (x3)^(1/2) > 80 Let x3 be deleted from S > 90 Let x4 be joined to S > 100 Goto 20 > ------------------------------- > Now, it might be equivalent to some type of recursive function, but whats > the symbol for select at random ? > Whats the symbol for delete from S ? > Whats the symbol for join x1 to S ? > I have never seen union and intersection operators used in a difference > equation, or on the ßy. In fact, I dont think that any first order > logical operators have ever been used dynamically - as one would construct > coupled differential equations, or other recursive relations. I have never > seen this. Have you ? OK - I said stupid things again. First, you can have infinite unions and infinite intersections. This is well known. Secondly, in the algorithm above, you can let S be a subset of R or something, and instead of deleting from S you can simple say not contained in S. It probably equivalent. I dont think its neccesary to have a function which modifies R itself, if you can just select subsets of R and you get the equivalent result. Back to square one - maybe - === Subject: Re: Dynamic domain ? the > empty set. I suggest you look sci.logic, thread logic is obsolete. > In fact, sci.logic is a more appropriate location for your > Ôobjective posts as also alt.math.recreational. > They threw me out. Im a usenet refugee. Awe come on, I dont believe you. If they threw you out at sci.logic, you would have been fried at sci.math. Tell you what, put next your post in sci.logic instead of sci.math, perhaps upon timecube. Then well know. We may even get more cross chatter there than what weve been getting here. === Subject: Re: Dynamic domain ? > Im back once again, bloodied, but sincere. I have come to the conclusion > that what I am doing is probably just stupidity, but I have resolved that if > I am to engage myself in stupidity, then I might as well excell in it. So, I > have refined my idiocy yet again, and here it is - > --------------------------------- > Example----------------- > Given two physical objects in the physical universe, O1 and O2. > Let O1 be a block of steel. > Let O2 be a given quantity of heat energy. > O1 and O2 are both unique physical objects. You lost me there. Couldnt the same quantity of heat energy exist in many different places? If I take two pieces of steel and heat them both energy? I think youre fooling yourself with semantic games. === Subject: Re: Dynamic domain ? > Im back once again, bloodied, but sincere. I have come to the conclusion > that what I am doing is probably just stupidity, but I have resolved that if > I am to engage myself in stupidity, then I might as well excell in it. So, I > have refined my idiocy yet again, and here it is - > --------------------------------- > Example----------------- > Given two physical objects in the physical universe, O1 and O2. > Let O1 be a block of steel. > Let O2 be a given quantity of heat energy. > O1 and O2 are both unique physical objects. > You lost me there. Couldnt the same quantity of heat energy exist in > many different places? If I take two pieces of steel and heat them both > energy? I think youre fooling yourself with semantic games. Very likely yes - I am probably just going up against a brick wall. But just for the sake of argument - Whatever heat is made of, if you have a certain quantity of it in a certain place it is unique. That is, no other quantity of heat is identical to it. You might be able to have two separate samples with nearly identical quantities of heat, but the samples are in two different locations. They are unique. Same with the chunk of steel. The actual objects in the example are arbitrary, I just used them to illustrate that the domain consists of real objects and not abstract ones. I was trying to use the idea that All physical objects are unique. If that were true, then maybe you can build on it. Thats what Im trying to do. There was a thread about it a few weeks ago. I will probably chase my tail until Ive proved the whole thing futile, and my folly will serve as an example for others to avoid. : ) === Subject: Re: Dynamic domain ? > Im back once again, bloodied, but sincere. I have come to the > conclusion > that what I am doing is probably just stupidity, but I have resolved > that if > I am to engage myself in stupidity, then I might as well excell in it. > So, I > have refined my idiocy yet again, and here it is - > --------------------------------- > Example----------------- > Given two physical objects in the physical universe, O1 and O2. Let O1 be a block of steel. > Let O2 be a given quantity of heat energy. O1 and O2 are both unique physical objects. > You lost me there. Couldnt the same quantity of heat energy exist in > many different places? If I take two pieces of steel and heat them both > energy? I think youre fooling yourself with semantic games. > Very likely yes - I am probably just going up against a brick wall. But just > for the sake of argument - > Whatever heat is made of, if you have a certain quantity of it in a > certain place it is unique. That is, no other quantity of heat is identical > to it. You might be able to have two separate samples with nearly identical > quantities of heat, but the samples are in two different locations. They are > unique. Same with the chunk of steel. > The actual objects in the example are arbitrary, I just used them to > illustrate that the domain consists of real objects and not abstract ones. > I was trying to use the idea that All physical objects are unique. If > that were true, then maybe you can build on it. Thats what Im trying to do. > There was a thread about it a few weeks ago. > I will probably chase my tail until Ive proved the whole thing futile, and > my folly will serve as an example for others to avoid. : ) I believe I can identify the source of the confusion. Quantity of heat is not a thing that has existence in the universe. Its an abstraction. Something that exists only in the world of thought. (Of course thought itself, being a byproduct of measurable electrical activity in the brain, has physical existence. But then we have to ask whether consciousness has physical existence, and wed have to move to alt.amateur.metaphysics.) Anyway what you really have is a piece of steel, on the one hand, and a couple zillion little molecules (the molecule is the traditional level of discourse for discussions of heat -- rather than atoms or quarks or strings or whatever). Each of those individual molecules is unique, and is moving around with a certain amount of energy. The energy dissipated from the collisions as the molecules bounce around against each other, is what we call heat. But the amount of heat, as a specific thing, is an ABSTRACTION. It is a thought, like a set or truth or justice or even the number 5. Abstractions dont follow the same rule of uniqueness as physical objects do. There are many many individual marbles in the world, but there is only one abstract concept marble that applies to each of the individual physical marbles. === Subject: Re: Dynamic domain ? Im back once again, bloodied, but sincere. I have come to the > conclusion > that what I am doing is probably just stupidity, but I have resolved > that if > I am to engage myself in stupidity, then I might as well excell in it. > So, I > have refined my idiocy yet again, and here it is - > --------------------------------- > Example----------------- > Given two physical objects in the physical universe, O1 and O2. Let O1 be a block of steel. > Let O2 be a given quantity of heat energy. O1 and O2 are both unique physical objects. You lost me there. Couldnt the same quantity of heat energy exist in > many different places? If I take two pieces of steel and heat them both > energy? I think youre fooling yourself with semantic games. > Very likely yes - I am probably just going up against a brick wall. But just > for the sake of argument - > Whatever heat is made of, if you have a certain quantity of it in a > certain place it is unique. That is, no other quantity of heat is identical > to it. You might be able to have two separate samples with nearly identical > quantities of heat, but the samples are in two different locations. They are > unique. Same with the chunk of steel. > The actual objects in the example are arbitrary, I just used them to > illustrate that the domain consists of real objects and not abstract ones. > I was trying to use the idea that All physical objects are unique. If > that were true, then maybe you can build on it. Thats what Im trying to do. > There was a thread about it a few weeks ago. > I will probably chase my tail until Ive proved the whole thing futile, and > my folly will serve as an example for others to avoid. : ) > I believe I can identify the source of the confusion. Quantity of heat > is not a thing that has existence in the universe. Its an abstraction. > Something that exists only in the world of thought. (Of course thought > itself, being a byproduct of measurable electrical activity in the > brain, has physical existence. But then we have to ask whether > consciousness has physical existence, and wed have to move to > alt.amateur.metaphysics.) > Anyway what you really have is a piece of steel, on the one hand, and a > couple zillion little molecules (the molecule is the traditional level > of discourse for discussions of heat -- rather than atoms or quarks or > strings or whatever). Each of those individual molecules is unique, and > is moving around with a certain amount of energy. The energy dissipated > from the collisions as the molecules bounce around against each other, > is what we call heat. But the amount of heat, as a specific thing, is > an ABSTRACTION. It is a thought, like a set or truth or justice or > even the number 5. Abstractions dont follow the same rule of > uniqueness as physical objects do. There are many many individual > marbles in the world, but there is only one abstract concept marble > that applies to each of the individual physical marbles. Agreed - but lets simplify it a little. Let O1 be a blob of white clay. O1 is unique. Let O2 be a blob of black clay. O1 is unique. Now, smash them and mush them together. You have O3, a blob of gray clay, and O3 is also unique. Further, O1 and O2 no longer exist. And, you have an O3 which did not exist previously. The operation of mushing together is unaffected, but the domain has changed. You could probably extend this to the rest to all physical objects, but just trying to keep it simple for the mean time. I dont know of any mathematical operators which will do this - actually modifying the domain that they are defined for. Seems like some 1st rate lunacy, certainly more interesting than your run-of -the-mill, garden-variety nonsense. === Subject: Re: Dynamic domain ? Im back once again, bloodied, but sincere. I have come to the > conclusion > that what I am doing is probably just stupidity, but I have resolved > that if > I am to engage myself in stupidity, then I might as well excell in > it. > So, I > have refined my idiocy yet again, and here it is - > --------------------------------- > Example----------------- > Given two physical objects in the physical universe, O1 and O2. Let O1 be a block of steel. > Let O2 be a given quantity of heat energy. O1 and O2 are both unique physical objects. You lost me there. Couldnt the same quantity of heat energy exist in > many different places? If I take two pieces of steel and heat them > both > energy? I think youre fooling yourself with semantic games. > Very likely yes - I am probably just going up against a brick wall. But > just > for the sake of argument - Whatever heat is made of, if you have a certain quantity of it in a > certain place it is unique. That is, no other quantity of heat is > identical > to it. You might be able to have two separate samples with nearly > identical > quantities of heat, but the samples are in two different locations. They > are > unique. Same with the chunk of steel. > The actual objects in the example are arbitrary, I just used them to > illustrate that the domain consists of real objects and not abstract > ones. I was trying to use the idea that All physical objects are unique. > If > that were true, then maybe you can build on it. Thats what Im trying to > do. > There was a thread about it a few weeks ago. > I will probably chase my tail until Ive proved the whole thing futile, > and > my folly will serve as an example for others to avoid. : ) > I believe I can identify the source of the confusion. Quantity of heat > is not a thing that has existence in the universe. Its an abstraction. > Something that exists only in the world of thought. (Of course thought > itself, being a byproduct of measurable electrical activity in the > brain, has physical existence. But then we have to ask whether > consciousness has physical existence, and wed have to move to > alt.amateur.metaphysics.) > Anyway what you really have is a piece of steel, on the one hand, and a > couple zillion little molecules (the molecule is the traditional level > of discourse for discussions of heat -- rather than atoms or quarks or > strings or whatever). Each of those individual molecules is unique, and > is moving around with a certain amount of energy. The energy dissipated > from the collisions as the molecules bounce around against each other, > is what we call heat. But the amount of heat, as a specific thing, is > an ABSTRACTION. It is a thought, like a set or truth or justice or > even the number 5. Abstractions dont follow the same rule of > uniqueness as physical objects do. There are many many individual > marbles in the world, but there is only one abstract concept marble > that applies to each of the individual physical marbles. > Agreed - but lets simplify it a little. > Let O1 be a blob of white clay. O1 is unique. > Let O2 be a blob of black clay. O1 is unique. > Now, smash them and mush them together. > You have O3, a blob of gray clay, and O3 is also unique. > Further, O1 and O2 no longer exist. And, you have an O3 which did not exist > previously. The operation of mushing together is unaffected, but the > domain has changed. Ok, thats much clearer. > You could probably extend this to the rest to all physical objects, but just > trying to keep it simple for the mean time. > I dont know of any mathematical operators which will do this - actually > modifying the domain that they are defined for. Seems like some 1st rate > lunacy, certainly more interesting than your run-of -the-mill, > garden-variety nonsense. I dont know, this reminds me a little of what happens when you take 3 and combine it with 5 to get 8. Whered the 5 and the 3 go? They are both present in the 8. In fact 8 = 5+3 after youve put 5 and 3 together, just as claylump 03 is made up of claylumps 01 and 02. If you took 03 and took away all the atoms that used to be part of 01, youd be left with 02. === Subject: Cantor Normal Form by support1.mathforum.org (8.11.6/8.11.6/The Math Forum, $Revision: 1.9 primary) id iAK471W20421; Hi guys, What is the Cantor Normal Form of ordinals? Why is it that the Cantor Normal form of w + w^2 + w^3 + w^4 + 2 = w^4 + 2? And what would be the CAntor Normal Form of (w+3)^5 + (w^2+17).(w+8) + w^12 ? === Subject: Re: Cantor Normal Form >Why is it that the Cantor Normal form of w + w^2 + w^3 + w^4 + 2 = w^4 + 2? This one is so simple that even I can answer it. Why is the Cantor Normal Form of 1 + w equal to w, while the Cantor Normal Form of w + 1 equal to w + 1? This is because an ordinal refers to the structure of an ordered set. The set {A, 1, 2, 3, 4,...} has the same structure as the set {1, 2, 3, 4, 5,...}; just re-name A as 1, 1 as 2, 2 as 3, and so on. So, in general, appending a small ordinal to a big ordinal on the left doesnt change the structure. But the set {1, 2, 3, 4,... A} has a different structure; you keep counting forever, and you never get to A; A is after the infinite counting process. John Savard http://home.ecn.ab.ca/~jsavard/index.html === Subject: Re: Cantor Normal Form > What is the Cantor Normal Form of ordinals? Why is it that the Cantor > Normal form of w + w^2 + w^3 + w^4 + 2 = w^4 + 2? > And what would be the CAntor Normal Form of > (w+3)^5 + (w^2+17).(w+8) + w^12 ? w^12 because all the other exponents after expanding the expressions are less than 12. === Subject: Re: Cantor Normal Form > Hi guys, > What is the Cantor Normal Form of ordinals? Why is it that the Cantor > Normal form of w + w^2 + w^3 + w^4 + 2 = w^4 + 2? Ôcos w + w^2 = w^2 =/= w^2 + w etc. A simpler example: 1 + w is the order type of a singleton followed by a simple infinite sequence, that is it looks like *, *, *, ..... so its a simple infinite sequence: 1 + w = w. But w + 1 is the order type of a simple infinite seuqence followed by a singleton: so *, *, *, .... * Not the same as w :-) -- Robin Chapman, www.maths.ex.ac.uk/~rjc/rjc.html Lacan, Jacques, 79, 91-92; mistakes his penis for a square root, 88-9 Francis Wheen, _How Mumbo-Jumbo Conquered the World_ === Subject: Re: Cantor Normal Form >> Hi guys, >> What is the Cantor Normal Form of ordinals? Why is it that the Cantor >> Normal form of w + w^2 + w^3 + w^4 + 2 = w^4 + 2? > Ôcos w + w^2 = w^2 =/= w^2 + w etc. > A simpler example: 1 + w is the order type of a singleton followed > by a simple infinite sequence, that is it looks like > *, *, *, ..... > so its a simple infinite sequence: 1 + w = w. > But w + 1 is the order type of a simple infinite seuqence followed > by a singleton: so > *, *, *, .... * > Not the same as w :-) Concrete models clarify this: 1 + w = w e.g. {0} / N = N but w + 1 != w e.g. N /{oo} != N Note esp. N /{oo} contains an infinite elt oo > n with no immediate predecessor, but N has no such elt. --Bill Dubuque === Subject: Difference between FT & LT Hi there, Fourier transform convert the time domain function into frequency domain and so the Laplace transform. Then who do they differ? Fourier transform work at complex frequency and that of Laplace transform works at s plane, also they have different limits of integration, is this all how they differs? I need some intuitive understanding, how they actually work. Any help is appreciated === Subject: Turing Machines and Physical Computation Hi Stephen, I would have expected a thoughtful reply. > I have had such a discussion with an extremely intelligent and > experienced mathematician. He told me that PCs are not Turing > Machines, because they have an infinite tape. I think he did not > know anything about descriptive complexity. This infinite portion of > the tape consists entirely of blank symbols, and therefore has > descriptive complexity O(1), which is easily realized by a physical > system. When I told him about Ullmans indefinite growing argument, he > objected But when the universe is filled up, it cannot grow any more! > Then, it is not infinite, to which I responded Yes, but there is > *nothing* that is larger than the universe. To assume the contrary > would be theology, which I despise. > Turing Machines are idealized which means they are not physically realized. What a nice assertion. A TM is just the specification of a very low level machine code, thats all there is to it. Its just another model of computation, and not an extremely telling or useful one. Thinking about Turing Machines which have not been realized yet does not mean that these things cannot be implemented. Besides, a bounded size FSA simulator, too, is a Turing Machine... You people overlook this simple point, I wonder why. Also, I suggest you to get the most recent edition of Cinderella book and have a look at what Ullman thinks about this subject. (Thats another argument!) IIRC, in that edition, the authors argue persuasively that we should think of PCs as TMs rather than DFAs. I find that a subtle point. Now, I recall that you made this strange argument about Turing Machines being able to do things that real computers cannot, because they have an infinite tape. What an observation. > TMs are not meant to have physical constraints applied to them. Another assertion. Ignoring physical plausibility directly opposes physicalism. When we start talking about immaterial things, we are not making scientific statements, we are making metaphysical ones, and that is not a good sign if the metaphysical statements depict worlds that are not physically similar to our own. It is a matter of degree, which we can observe. The question is: how far from reality? The further you talk, the less real your statements are, not just as real! > That mixes categories. No. > Sometimes the question is asked, how many sentences can be > generated in some natural (say English) language? There are finitely many > words in the language, but the standard answer is that there are countably > infinite number of sentences, due to appending etc. That is potential infinity, a plausible concept, considering time for instance. Current theory of physics *seems* to suggest that time is going to continue forever. The idea of potential infinity is then, at least in the temporal sense, not too far from our world. However... > These kind of questions ask what is the potential in theory, not what is > practically possible. Observations like: a person can only articulated > finitely > many sentences in a lifetime, or any sentence has to be uttered before > somebody dies or a machine wears out, or that how many sentences > potentially exist is related to how many people generate sentences over > the lifetime of humanity in the universe are not relevant, because that is > not the question being asked. Every process within the universe is finite > due to heat death of the universe, so that makes all such questions trivial, > if one interprets them to mean or apply to a physical reality. Thats a quite amazing thought, because it rejects that some facts about our universe can be simple. That some answer is trivial does not necessarily mean it is wrong. If we are talking about our universe, yes, if universe is going to expand, and accelerating in expansion, then, at some time T no efficient causal interaction will remain, which will disable large computations. Sad for the universe. But what else can we say? Then, those never-ending computations arent quite possible. If thats so, its not sensible to talk about things that cannot ever be constructed in our world. Then, lets talk of finite quantities only. Lets see how big computations behave, without pretending that there is no bound to their time/space use. At this point, I should remind you the famous Levin quote. Levin was Kolmogorovs student, so he probably has a better idea of this issue than you have. > A Turing > Machine or potential sentence of a language (there is no pre-existing > specification that the sentence has to be of finite length) is not of this > world. Of which world is it then? (^_^) And you are saying this Platonist talk is not theology! You have just murdered physicalism. > The set of natural numbers is countably infinite and is has some use > theoretically. Would you claim infinite sets have no use because they It has some use theoretically. An immortal being is nice in theory, as well, but we dont know if it will work out well for us. But that is a sorry analogy. We can do better. God has some use theoretically, we can use it to resolve our ethical problems. But we dont know if it exists. Its just an idea. As you can see, its pointless to say that the set of natural numbers exist except as an idea. And that is what you are affirming in the first sentence. The second is nonsense. I say nothing about their theoretical use, they make good mental exercise, and they help us construct simpler theories in exchange for loss of physicality. (Again, when it becomes less physical, it does not automatically gain some positive ontological status, if you are also a physicalist!) That something has some use theoretically does not grant attaching the word exists to it, from a philosophical point of view. And giving it a privilege might betray philosophical consistency. > And the original description of a Turing Machine. It is common to call > this tape Ôinfinite though some prefer finitely unbounded. The latter camp has the precise terminology. > There is no > physical time constraint applied to when the calculation has to be > completed. If you mean *any* computation. But a Turing Machine is a *particular* computer. Not just *any* computer. Lets pay attention to our language. > So there are calculations that a physical PC the size of > a galaxy could not complete before the universe ran out of power to > energize the computer. A Turing Machine can of course complete > such a calculation (because the calculation does not need to be infinite, > just finitely larger/longer in time that can be accomplished by any > physical device during the existence of the physical universe) because > the constraint of physical time is not applied to idealized situations. Wittgenstein once said Turings theory was of human computers. Which was quite true if we take the original paper literally, without abstracting computer. (And that is what such people were called at the time, who made calculations) You are also making a significant conceptual error. We have a theory T, only a small portion of which has models in the real world. But no experiments contradict our theory (such as computers existing,that cannot be explained by T). I think this is a perfectly legitimate situation in science. And you are twisting the whole physicalist argument upside-down by saying that, since the theory predicts (by way of *generalization*) Ôthere would be machines which can grow absolutely with no end, if and only if our universe had an infinite space; *then* you conclude that this theory must not be a physical theory. What a bad use of language! Instead you should have paid attention to basic rules of grammar and linguistic analysis. What the theory predicts is a *counterfactual*, it is not too different from saying that If my mother had a beard, she would have a lot of hair on her chin. This is quite possibly *false* for most of our mothers. And for our world, the theory *predicts* that there will be no machines which can grow absolutely with no end, since our universe does not have an infinite space. It is regrettable to think of the theory as independent from physical statements, if we accept that it is a theory of *machines*. Anyway, the point remains that Turings theory is a theory of actual machines, if not merely humans. Wittgenstein has a point! And then it is nonsense to argue that: > A Turing Machine can of course complete such a calculation .... because the > constraint of physical time is not applied to idealized situations. But that is a terrible metaphysics you have there! Idealized situations do not exist. By situation we mean a complex aggregate of physical events, nothing more. (Again, if we are to call ourselves physicalists. And Cartesian Dualists, can leave the hall silently!) > Keeping those categories seperate, the idealized and the physical, > is definitional. The answer to theoretical questions is trivial and obvious > if you mix these categories. Mathematicians invented infinity without > the requirement that it be physically realized because it was useful. > Pure mathematics invents formal mathematical systems with no > requirement that this formal system represent any physical event or > process. This is quite a muddled reasoning, especially this bit: > Pure mathematics invents formal mathematical systems with no > requirement that this formal system represent any physical event or > process. There is no requirement of representation, so you think. There is the requirement of representation of *ideas* in your head, and if your ideas are *physical*, then it follows that the *exact opposite* of your statement holds! > Yes, but there is > *nothing* that is larger than the universe. To assume the contrary > would be theology, which I despise. > When you say *nothing* you mean no physical something. Platonist semantics. *shudder* When you utter nothing, you do not refer to anything that exists. You do not refer to something that does not exist! (That is generally seen as a wrong account of designating the reference of expressions with counter-factuals in philosophy of language.) That would be a very confused understanding of the word nothing. Lets do some ordinary philosophy of language to draw a better picture. Here are some easy semantics questions. Formalize the semantics of the following sentences, excluding questions using common knowledge representation techniques in First Order Logic: (I am explicitly asking for truth-referential semantics, of course. Usual Tarskis World stuff, if you are familiar with formal semantics) - What do you want? - I want nothing. - What are you going to do tomorrow? - I am going to do nothing. There is nothing in the box. * An example of an analytically false statement (for nonempty interpretation domains) Everything is nothing. (Hint: the solution is like the liar paradox) > Mathematical > objects need not be physical. A Turing Machine is not just a mathematical object! [*] Lets repeat our basic argument again. 1. Not all Turing Machines require finite bounded space. 2. Therefore some Turing Machines run in finite bounded space. 3. Many PCs do just that. 4. Then, PCs are physical functioning models of Turing Machines. (But most of them are also simple DFAs, or formal axiomatic systems, or whatever general theory they fit. The theory which has the most *explanatory* power will be preferred according to the question we are trying to answer.) Could this argument be any simpler? > When you made this comparison, infinity and theology/God, to the size > of the physical universe, you crossed over from debating potential vs. > actual infinities to declaring abstract thinking is just theology in another > guise. That is exactly what Poincare implied in his famous remark. I will bet on Poincare, and not on your championing of one school of mathematics. (I am not the only person who made the comparison!) ever discuss foundational issues with those who cannot question the assumptions of their favorite school of thought? What I explained to a slightly confused mathematician who believed himself to be a constructivist was that a sane analysis in philosophy of computation suggests that Turing Machines should be thought of physical devices, if we are to remain physicalists. You do not challenge any of the arguments. Instead, you assert things, like saying that Turing Machines are not of this world. Show us that world, or is it the fairy-land of mathematics? [snip some philosophy] Amused, -- Eray Ozkural [*] And you might as well say, our language expressions do not need to refer to physically plausible things. Then, you should perhaps think of defending that we freely talk of God in scientific discourse. But that is not permissible in scientific talk. Maybe it is good for mythology, which is not our business. === Subject: Re: Turing Machines and Physical Computation Ah, modern symbolic logic, even translated to English, is so much clearer and less prone to false word arguments than ancient platonic logic language. Its a joy for me to translate from your platonic language to modern: > - What do you want? > - I want nothing. It is not true that there exists X such that I want X. > - What are you going to do tomorrow? > - I am going to do nothing. It is not true that there exists X such that I am going to do X tomorrow. > There is nothing in the box. It is not true that there exists X such that X is in the box. > Everything is nothing. It is not true that there exists X. -or- For all X, it is not true that there exists Y such that Y is in X. === Subject: Re: Turing Machines and Physical Computation >> I have had such a discussion with an extremely intelligent and >> experienced mathematician. He told me that PCs are not Turing >> Machines, because they have an infinite tape. I think he did not >> know anything about descriptive complexity. This infinite portion of >> the tape consists entirely of blank symbols, and therefore has >> descriptive complexity O(1), which is easily realized by a physical >> system. When I told him about Ullmans indefinite growing argument, he >> objected But when the universe is filled up, it cannot grow any more! >> Then, it is not infinite, to which I responded Yes, but there is >> *nothing* that is larger than the universe. To assume the contrary >> would be theology, which I despise. It is true that a Turing Machine is not infinitely complex to describe. But it also remains true that a PC is not capable of performing a computation which requires an infinite amount of intermediate results, or even a large finite amount of intermediate results which is larger than the capacity of its storage devices. Mathematics deals with the infinite, and the arbitrarily large finite, and, thus, computations requiring more intermediate storage than the whole Universe could supply are real and meaningful in mathematics; to exclude them would only make things more complicated, not simpler. (And we do not even know exactly how big the Universe is.) John Savard http://home.ecn.ab.ca/~jsavard/index.html === Subject: Re: Turing Machines and Physical Computation >> Turing Machines are idealized which means they are not physically realized. So are tigers, Buicks, the letter q, ... any noun, much less any natural kind. I guess nothing exists but ideas. Of course, that means ideas are of no use in dealing with actual objects. This is Modern Cartesianism - in its worst form, as I often defend Descartes of many of the sins attributed to him. As soon as you assume into the problem a divide between ideas and the physically realized, you are assured of never finding a solution to major problems. >> And the original description of a Turing Machine. It is common to call >> this tape Ôinfinite though some prefer finitely unbounded. ... >> So there are calculations that a physical PC the size of >> a galaxy could not complete before the universe ran out of power to >> energize the computer. The question is why a physical computer can do anything at all, and what the limits are of any particular class of physical computers. Im sure there is a limit to the size that you can build balls of string in this universe, before they collapse of their own mass into black holes. That does not mean that somewhat smaller - and in fact, rather large! -- balls of string cannot be built or studied. -- Bottom line: if you see even the tiniest trace of idealism in a theory about computation, expunge it or discard the entire theory, because you are certainly wasting your time dealing with it. J. === Subject: Re: Turing Machines and Physical Computation http://mygate.mailgate.org/mynews/comp/comp.theory/ 61bad26451853979aa12696535 2b4240.48257%40mygate.mailgate.org > Hi Stephen, > I would have expected a thoughtful reply. Perhaps if you had avoided wandering off in the weeds again you would have received one? The reactions you receive from others are the reactions _you_ _provoke_ by _your_ behavior. This is a constant of the universe. Failing to understand that permanent reality has a technical name: autism. > I have had such a discussion with an extremely intelligent and > experienced mathematician. He told me that PCs are not Turing > Machines, because they Turing Machines, not PCs. > have an infinite tape. > I think he did not know anything about > descriptive complexity. And I think this is merely another example of you failing to pay attention in class. > This infinite portion of the tape consists > entirely of blank symbols, and therefore has > descriptive complexity O(1), Ummm, no, that doesnt even make sense, since the infinite portion of the tape does not have a known starting position. There are Turing Machine programs which will overwrite any mark you place on the tape and say, from here on out, I can describe this with O(1) complexity, so that refuge is unavailable to you as a way to limit the complexity of describing the tape as a whole. > which is easily realized by a physical system. Again, you snoozed when you should have been taking notes. Not being realizable in any physical system is one well known attribute of Turing Machines. > When I told him about Ullmans indefinite > growing argument, he objected But when the > universe is filled up, it cannot grow any more! > Then, it is not infinite, to which I responded > Yes, but there is *nothing* that is larger than > the universe. To assume the contrary would be > theology, which I despise. The problem being that it is precisely what _you_ are doing, trying to limit abstract devices to the bounds appropriate to mere physical reality, that is theology. You cannot both limit the construct you are discussing to the bounds of the physical universe, and pretend that you are still discussing Turing Machines, which specifically have no such limitations. You can call your construct an Eray Machine if you choose, but much like the Olcott Machines previously proposed here, your devices will be toys, of no intellectual interest whatever, where Alan Turings invention is one of the most powerful constructs ever produced by the human mind, and finds constant new applications. >> Turing Machines are idealized which means they >> are not physically realized. > What a nice assertion. That is not an assertion, that is a definition. Perhaps alertness during your classes would have taught you the difference? > A TM is just the specification of a very low level > machine code, thats all there is to it. Well, no. Perhaps, rather than filling Usenet with endless more reams of pointless blather, you could go find out _on your own_ what a Turing machine is, and what that implies, rather than conducting another bulldog defense of your chosen battlefield of intensely applied ignorance here in this venue, and spare the rest of us the misery of wading through your endless time wasting eructions? > Its just another model of computation, and not an > extremely telling or useful one. My, you have a lot of opinions grounded in utter ignorance. That one alone should have prevented your ever receiving a PhD in the computer desmesne. > Thinking about Turing Machines which have not been > realized yet does not mean that these things > cannot be implemented. Your these things is a reference without a referent. > Besides, a bounded size FSA simulator, too, is a > Turing Machine... You have two concepts too muddled to be easily separated, like siamese twins. Perhaps you could borrow some class notes from someone who bothered to pay attention in school? > You people overlook this simple point, I wonder > why. Perhaps because we people set enough value on our education to be mentally present in class as well as physically there? > Now, I recall that you made this strange argument > about Turing Machines being able to do things that > real computers cannot, because they have an > infinite tape. What an observation. Again, you bemusedly give your mere ignorance-based _opinion_ the same stature as the received wisdom of the computer science theory community. That may amuse you, but it makes you clearly and publically the idiot you are so determined to be, also. >> TMs are not meant to have physical constraints >> applied to them. > Another assertion. Again you confuse opinion with definition. That is no more an assertion than is gravity works. > Ignoring physical plausibility directly opposes > physicalism. So what? When you go wandering off into the weeds where your abberant philosophy lives, you leave Turing Machines, and computer theory, far behind. Turing Machines are under precisely _no_ obligation to be physically realizable. They teach this point in school, Eray, where were you at the time? > When we start talking about immaterial things, we > are not making scientific statements, we are > making metaphysical ones, and that is not a good > sign if the metaphysical statements depict worlds > that are not physically similar to our own. Im pretty sure at this point you have stepped well past the bounds of sane thinking. You are trying to limit science to physical science, and that limitation only exists in your own mind. > It is a matter of degree, which we can observe. That statement is a meaningless noise. > The question is: how far from reality? The further > you talk, the less real your statements are, not > just as real! Again, you are expressing some degree of insanity, no degree of intelligence or attention to your education, here. I refuse to waste more time on your inane drivel. This should be clues enough you need to go back and _learn_ that which you have inappropriately already claimed credit to have learned with your accepting a PhD. xanthian, disgusted. -- === Subject: Re: Turing Machines and Physical Computation >Turing Machines are under precisely _no_ obligation >to be physically realizable. They teach this point >in school, Eray, where were you at the time? I dont know where Eray was, but from the moment I first heard this sort of stuff, I wondered about it. Many false fact are taught in school, though their falsity may not be overturned until years or centuries later. Dont just appeal to authority here. Technically, sure, one can study Turing Machine functions that cannot be physically realized. But that does not make Turing Machine theory inapplicable to machines that can be realized. >Im pretty sure at this point you have stepped well >past the bounds of sane thinking. You are trying to >limit science to physical science, and that >limitation only exists in your own mind. Would you like to give an example of non-physical science? J. === Subject: Re: Turing Machines and Physical Computation >Turing Machines are under precisely _no_ obligation >to be physically realizable. They teach this point >in school, Eray, where were you at the time? > I dont know where Eray was, but from the moment I first heard this > sort of stuff, I wondered about it. Many false fact are taught in > school, though their falsity may not be overturned until years or > centuries later. Dont just appeal to authority here. Technically, > sure, one can study Turing Machine functions that cannot be physically > realized. But that does not make Turing Machine theory inapplicable > to machines that can be realized. Well, our instructors were careful enough to teach us the Cinderella book which says no such stupid thing. It talks about abstract machines, but it takes pains to make it awfully clear that this is indeed the theory of real-world computers. Abstract does not mean non-physical, and Im grateful that the authors are clever persons. I wonder, can these so-called hobbyists of theory like Harris and Dolan provide for me a reference from a respected theory of computing textbook that claims Turing machines are inapplicable to machines that can be realized? I would be quite surprised with that. For a reasonable computer scientist, the Turing Machine is just another kind of automata, and its mechanism is firmly rooted in the physical world. There is no ontological difference between a PDA and a TM. It is no magic construction. When we see the transition graph of a TM, etc. we immediately know that this is just another computer. And it is one among many models of c.e. computation. Only these self-branded sci.math philosophers seem to insist on this naive idealist talk. And in our textbooks, it is clearly written: the ID of a TM is finite at all times. This is a physical machine specification. I wonder. Will these people also say that Lambda calculus depicts non-physical processes? That the mundane task of substituting and rewriting is in fact a non-physical thing? I wonder that very much. Because *if* the TM is equivalent to evaluation of Lambda calculus expressions, then that should be the case. This is I believe a sufficient refutation of years of Harriss posts full of misconceptions about the subject. You see, all that is happening is that the theory programs on these peoples brains, which seems short of a stack, crashes the moment they see the word infinity somewhere. There are surely skyhook workers who would imagine hypercomputation and other physically impossible classes of machines, but lets see, we dont really deal with that in any reasonable curriculum. Computer Science is first and foremost the science of complex physical events. Computer Science does not deal with what an angel could have done in heaven, assuming he could process an infinite amount of information in a finite time. That *is* theology. And it doesnt work. We like things that work. >Im pretty sure at this point you have stepped well >past the bounds of sane thinking. You are trying to >limit science to physical science, and that >limitation only exists in your own mind. > Would you like to give an example of non-physical science? Lester uttered geometry, logic, math as examples. However, he may be neglecting that these disciplines too are based on our sensory experience. That is their true foundation. (However, it may not be precise to call these sciences in their present state.) On the other hand, these are seen more analytic than the purely empirical branches of inquiry, naturally. That is not to say that they should be indulging in useless metaphysics, though. There are surely measures for the utility of their statements. For mathematics, we can know where to draw the line. For instance, there is no need to talk about actually infinite fractal objects. Nobody can observe such a thing in the world. What we can indeed observe is the unbounded nature of computation, a far more natural thing than the continuum, which has never existed, and never will. Of course, if one shows a physical phenomenon that makes it _necessary_ to invoke these absurd objects to explain them, then they are useful, and that would actually be a physical proof of the continuum, that there are indeed such infinite objects that are a part of our world! No such thing has been done. To propose a theory which is based on nomologically impossible axioms is most definitely in the realm of theology or bad metaphysics. Modern philosophy has no dealing with the non-physical, and it need not either. I am actually expecting a brilliant reply by some of the least sophisticated philosophers I have ever had the opportunity to meet, who are available on sci.math. Lets see these philosophers assert that Turing Machines are nonphysical entities. -- Eray Ozkural === Subject: Re: Turing Machines and Physical Computation [. . .] >>Im pretty sure at this point you have stepped well >>past the bounds of sane thinking. You are trying to >>limit science to physical science, and that >>limitation only exists in your own mind. >Would you like to give an example of non-physical science? Oh, geometry, math, logic. === Subject: Re: Turing Machines and Physical Computation Mr. Dolan, I dont deal with those in your intelligence class. Youd be wrong to think I will actually waste time with reading your posts. Yes, you fare better David Longley, but this is a discussion between me and Stephen, who is a very good reader, thinker, a philosopher, and a generally smart person, unlike you. I value Stephens ideas very much in general. I dont value your ideas, because I think you are an arrogant and stupid man. Dont try to abuse me. -- Eray === Subject: Re: Turing Machines and Physical Computation <419c4735$0$44080$5fc3050@dreader2.news.tiscali.nl> <419cd7d4$0$44068$5fc3050@dreader2.news.tiscali.nl> <4zrnd.46389$QJ3.16198@newssvr21.news.prodigy.com> <61bad26451853979aa126965352b4240.48257@mygate.mailgate.orgMr . Dolan, I dont deal with those in your intelligence class. Youd >be wrong to think I will actually waste time with reading your posts. >Yes, you fare better David Longley, but this is a discussion between >me and Stephen, who is a very good reader, thinker, a philosopher, and >a generally smart person, unlike you. be better off reading a good novel. In fact, thats all that much of this sort of philosophy is. Its fiction for the thinking man and you need to wise up to that. >I value Stephens ideas very much in general. For all the wrong reasons. Its the same disorder that Michaels is a victim of as is Harris himself. >I dont value your ideas, because I think you are an arrogant and >stupid man. Dont try to abuse me. But thats because you are ignorant and naive. In time, with any luck, but mainly through the inßuence of your environment, youll grow out of it. The sooner the better... (remember I said that ;-) -- David Longley http://www.longley.demon.co.uk === Subject: Re: Turing Machines and Physical Computation > Hi Stephen, > I would have expected a thoughtful reply. I gave you a factual reply. It doesnt take all that much thought because Ive already learned the definitions and been over this before, sometimes in your position, having misconceptions. >> I have had such a discussion with an extremely intelligent and >> experienced mathematician. He told me that PCs are not Turing >> Machines, because they have an infinite tape. I think he did not >> know anything about descriptive complexity. This infinite portion of >> the tape consists entirely of blank symbols, and therefore has >> descriptive complexity O(1), which is easily realized by a physical >> system. When I told him about Ullmans indefinite growing argument, he >> objected But when the universe is filled up, it cannot grow any more! >> Then, it is not infinite, to which I responded Yes, but there is >> *nothing* that is larger than the universe. To assume the contrary >> would be theology, which I despise. >> Turing Machines are idealized which means they are not physically >> realized. > What a nice assertion. It is a fact. I dont know how you missed this. A TM can be simulated, parts of its description realized, on a physical computer. But not the part that allows unbounded resources. The physical resources of the universe could be converted to physical memory for a computer and eventually would not suffice to match the resources of a Turing Machine. A TM is a theoretical machine that can compute some number X, which could not be contained if the physical universe down to sub-atomic A TM can compute X because it is an abstract theoretical process not a physical machine. There are no physical constraints applied to TMs while all PCs or physical computers operate under physical constraints. TMs are logical, theoretical entities, not machines as in a physical device. TMs have the same potential to solve computing problems as do the still theoretical quantum computers. I think the descriptional term is Ôcomputational power which does not mean speed of computation. A TM has the same level of computational power as a series or conceived as working in parallel with other TMs. Time is a physical constraint. They talk about differences in computational power when they compare a TM to a Super-TM. That is because a Super-Tm is idealized, or theoretically specified to use the real numbers which of course are infinite. Therefore there theoretical calculations will reach a new plateau of computational resolution. As you may know, physical computers use truncated, approximated representations of numbers which are finite. This difference in computational resolution does not exist between TMs in series or parallel, or quantum computers. Real world physical computers can overlap TMs if the problems they calculate have a practically realized boundary. For instance a PC can calculate two billion digits of Pi and a TM in theory can calculate two billion digits of Pi. A Tm run by simulation on a PC can calculate two billion digits of Pi. But the simulation runs out of gas, is not isomorphic to TM potential when problems involving huge huge huge memory space are required. All physical memory will be eventually expended, there is no endless adding to physical memory, and this is a well-known point. I realize that one of the causes of contention between us is that you think TMs are physically realized as devices rather than logical thought experiments. TMs were used to develop the definition of an algorithm, which is sort of circular. But that logical mathematical representation is not perfectly physically realized on a real world physical computer. Im going to provide > A TM is just the specification of a very low level machine code, > thats all there is to it. Its just another model of computation, and > not an extremely telling or useful one. > Thinking about Turing > Machines which have not been realized yet does not mean that these > things cannot be implemented. Besides, a bounded size FSA simulator, > too, is a Turing Machine... You people overlook this simple point, I > wonder why. > Also, I suggest you to get the most recent edition of Cinderella book > and have a look at what Ullman thinks about this subject. (Thats > another argument!) IIRC, in that edition, the authors argue > persuasively that we should think of PCs as TMs rather than DFAs. I > find that a subtle point. > Now, I recall that you made this strange argument about Turing > Machines being able to do things that real computers cannot, because > they have an infinite tape. What an observation. >> TMs are not meant to have physical constraints applied to them. > Another assertion. > Ignoring physical plausibility directly opposes physicalism. When we > start talking about immaterial things, we are not making scientific > statements, we are making metaphysical ones, and that is not a good > sign if the metaphysical statements depict worlds that are not > physically similar to our own. It is a matter of degree, which we can > observe. > The question is: how far from reality? The further you talk, the less > real your statements are, not just as real! >> That mixes categories. > No. >> Sometimes the question is asked, how many sentences can be >> generated in some natural (say English) language? There are finitely many >> words in the language, but the standard answer is that there are >> countably >> infinite number of sentences, due to appending etc. > That is potential infinity, a plausible concept, considering time for > instance. Current theory of physics *seems* to suggest that time is > going to continue forever. The idea of potential infinity is then, at > least in the temporal sense, not too far from our world. However... >> These kind of questions ask what is the potential in theory, not what is >> practically possible. Observations like: a person can only articulated >> finitely >> many sentences in a lifetime, or any sentence has to be uttered before >> somebody dies or a machine wears out, or that how many sentences >> potentially exist is related to how many people generate sentences over >> the lifetime of humanity in the universe are not relevant, because that >> is >> not the question being asked. Every process within the universe is finite >> due to heat death of the universe, so that makes all such questions >> trivial, >> if one interprets them to mean or apply to a physical reality. > Thats a quite amazing thought, because it rejects that some facts > about our universe can be simple. That some answer is trivial does > not necessarily mean it is wrong. If we are talking about our > universe, yes, if universe is going to expand, and accelerating in > expansion, then, at some time T no efficient causal interaction will > remain, which will disable large computations. Sad for the universe. > But what else can we say? Then, those never-ending computations arent > quite possible. If thats so, its not sensible to talk about things > that cannot ever be constructed in our world. Then, lets talk of > finite quantities only. Lets see how big computations behave, without > pretending that there is no bound to their time/space use. > At this point, I should remind you the famous Levin quote. Levin was > Kolmogorovs student, so he probably has a better idea of this issue > than you have. >> A Turing >> Machine or potential sentence of a language (there is no pre-existing >> specification that the sentence has to be of finite length) is not of >> this >> world. > Of which world is it then? (^_^) And you are saying this Platonist > talk is not theology! You have just murdered physicalism. >> The set of natural numbers is countably infinite and is has some use >> theoretically. Would you claim infinite sets have no use because they >> universe? > It has some use theoretically. An immortal being is nice in theory, as > well, but we dont know if it will work out well for us. But that is a > sorry analogy. We can do better. God has some use theoretically, we > can use it to resolve our ethical problems. But we dont know if it > exists. Its just an idea. As you can see, its pointless to say that > the set of natural numbers exist except as an idea. And that is what > you are affirming in the first sentence. The second is nonsense. I say > nothing about their theoretical use, they make good mental exercise, > and they help us construct simpler theories in exchange for loss of > physicality. (Again, when it becomes less physical, it does not > automatically gain some positive ontological status, if you are also a > physicalist!) > That something has some use theoretically does not grant attaching the > word exists to it, from a philosophical point of view. And giving it > a privilege might betray philosophical consistency. >> And the original description of a Turing Machine. It is common to call >> this tape Ôinfinite though some prefer finitely unbounded. > The latter camp has the precise terminology. >> There is no >> physical time constraint applied to when the calculation has to be >> completed. > If you mean *any* computation. But a Turing Machine is a *particular* > computer. Not just *any* computer. Lets pay attention to our > language. >> So there are calculations that a physical PC the size of >> a galaxy could not complete before the universe ran out of power to >> energize the computer. A Turing Machine can of course complete >> such a calculation (because the calculation does not need to be infinite, >> just finitely larger/longer in time that can be accomplished by any >> physical device during the existence of the physical universe) because >> the constraint of physical time is not applied to idealized situations. > Wittgenstein once said Turings theory was of human computers. Which > was quite true if we take the original paper literally, without > abstracting computer. (And that is what such people were called at > the time, who made calculations) > You are also making a significant conceptual error. We have a theory > T, only a small portion of which has models in the real world. But no > experiments contradict our theory (such as computers existing,that > cannot be explained by T). I think this is a perfectly legitimate > situation in science. And you are twisting the whole physicalist > argument upside-down by saying that, since the theory predicts (by way > of *generalization*) Ôthere would be machines which can grow > absolutely with no end, if and only if our universe had an infinite > space; *then* you conclude that this theory must not be a physical > theory. What a bad use of language! > Instead you should have paid attention to basic rules of grammar and > linguistic analysis. What the theory predicts is a *counterfactual*, > it is not too different from saying that If my mother had a beard, > she would have a lot of hair on her chin. This is quite possibly > *false* for most of our mothers. And for our world, the theory > *predicts* that there will be no machines which can grow absolutely > with no end, since our universe does not have an infinite space. It is > regrettable to think of the theory as independent from physical > statements, if we accept that it is a theory of *machines*. > Anyway, the point remains that Turings theory is a theory of actual > machines, if not merely humans. Wittgenstein has a point! And then it > is nonsense to argue that: >> A Turing Machine can of course complete such a calculation .... because >> the >> constraint of physical time is not applied to idealized situations. > But that is a terrible metaphysics you have there! Idealized > situations do not exist. By situation we mean a complex aggregate of > physical events, nothing more. (Again, if we are to call ourselves > physicalists. And Cartesian Dualists, can leave the hall silently!) >> Keeping those categories seperate, the idealized and the physical, >> is definitional. The answer to theoretical questions is trivial and >> obvious >> if you mix these categories. Mathematicians invented infinity without >> the requirement that it be physically realized because it was useful. >> Pure mathematics invents formal mathematical systems with no >> requirement that this formal system represent any physical event or >> process. > This is quite a muddled reasoning, especially this bit: >> Pure mathematics invents formal mathematical systems with no >> requirement that this formal system represent any physical event or >> process. > There is no requirement of representation, so you think. There is the > requirement of representation of *ideas* in your head, and if your > ideas are *physical*, then it follows that the *exact opposite* of > your statement holds! >> Yes, but there is >> *nothing* that is larger than the universe. To assume the contrary >> would be theology, which I despise. >> When you say *nothing* you mean no physical something. > Platonist semantics. *shudder* > When you utter nothing, you do not refer to anything that exists. > You do not refer to something that does not exist! (That is generally > seen as a wrong account of designating the reference of expressions > with counter-factuals in philosophy of language.) > That would be a very confused understanding of the word nothing. > Lets do some ordinary philosophy of language to draw a better > picture. > Here are some easy semantics questions. Formalize the semantics of the > following sentences, excluding questions using common knowledge > representation techniques in First Order Logic: (I am explicitly > asking for truth-referential semantics, of course. Usual Tarskis > World stuff, if you are familiar with formal semantics) > - What do you want? > - I want nothing. > - What are you going to do tomorrow? > - I am going to do nothing. > There is nothing in the box. > * An example of an analytically false statement (for nonempty > interpretation domains) > Everything is nothing. (Hint: the solution is like the liar paradox) >> Mathematical >> objects need not be physical. > A Turing Machine is not just a mathematical object! [*] > Lets repeat our basic argument again. > 1. Not all Turing Machines require finite bounded space. You mean that not all Turing Machines will need finite _unbounded_ space to solve a certain class of (less complex) problems. > 2. Therefore some Turing Machines run in finite bounded space. Yes, they can, though you didnt arrive at this quite correctly. > 3. Many PCs do just that. I think PCs must only do that much. Basically agree. > 4. Then, PCs are physical functioning models of Turing Machines. (But > most of them are also simple DFAs, or formal axiomatic systems, or I described this as overlapping in the class of problems they can both compute. And they both use an algorithmic procedure. It is high level programming languages which are considered Ôcomplex enough to exhibit or fall under the scope of Godels Inc. Theorem. > whatever general theory they fit. The theory which has the most > *explanatory* power will be preferred according to the question we are > trying to answer.) Im not sure what you mean by this. The explanation Ive presented covers the cases in which TMs can compute more complex problems than PCs because PCs require physical resources, are physical. That TMs have no limitations due to physical resources is a matter of definition, not debate. The explanation Ive presented covers the cases in which the resolution of complex computation problems overlaps, TMs and PCs enjoy the same functionality as to producing some answer within restricted boundaries. > Could this argument be any simpler? At this point, it misses saying how your TM/PC argument has a bearing on Cantors potential/actual infinity and his transfinite relative actual infinity which is quite different than the historical theological absolute actual infinity. Infinity and a PC are eliminated by physical reality and a TM and infinity are included by definition, Turings description of a hypothetical machine. Machine means works by rote, in a routine manner, as in mechanical, not some type of physical device. Because it inspired a physical device has no bearing on this, that I can see. TMs and PCs have a basic difference. > The PC does not have to actually run an arbitrarily growing software. > It suffices that it has this property *in principle*. This is so not > because of some deeper running assumption, but rather because of the > fact that many Turing machines run in bounded space. Not in principle, the PC has a finite restriction on physical resources. The PC cannot compute a large class of intractable problems that a TM can compute in principle. Sure they overlap for most practical purposes. But the idea of a potential infinity changing into an actual infinity is just another change in logical abstraction. It is not physical in any sense. Thus discussing this in terms of how PCs which are physical are like some TMs, isnt in the same category as potential and actual infinities which are entirely abstract. TMs which are abstract entities which do not have physical requirements is the correct level of focus for the potential/actual infinity abstraction which also does not have a physical implication. It is the TM which has unbounded resources in principle, not the PC. Adding to a PC will reach a limit. Infinity has no limit. >> When you made this comparison, infinity and theology/God, to the size >> of the physical universe, you crossed over from debating potential vs. >> actual infinities to declaring abstract thinking is just theology in >> another >> guise. > That is exactly what Poincare implied in his famous remark. I will bet > on Poincare, and not on your championing of one school of mathematics. > (I am not the only person who made the comparison!) ...Full Turing machine power cannot be _necessary_ for mental states. There is no evidence at all that cats and dogs, which clearly have mental states, or even human beings (when unaided by external memories), have the power of a Turing machine. E.g. we quickly get into trouble if we have to parse a deeply nested sentence, whereas this would not bother a Turing machine, or even many computers of lesser power. Even when we use external memory aids analagous to the Turing Machines tape, to help us with calculations or reasoning, we can still make mistakes of many kinds, that no functioning Turing machine would. When this happens we are still awake, thinking, seeing, feeling etc. Behavior thats unlike a Turing machine does not indicate a lack of mind. So it is not sheer computational power that is required for mentality. If computational abilities enter into mentality at all, it must have something to do with the partiuclar kinds of computations and the partiuclar kinds of mental capabilities, and it is quite possible that many of these require something less than Turing power, and at the same time something more, which Ill try to characterize below. ... Weve seen that theres vagueness in the causal requirements for an algorithm alleged to generate intelligence. Theres another kind of vagueness concerning a process produced by one algorithm (e.g. the UAI) and a process involving many different algorithms. Penrose apparently interprets an algorithm as a rule or set of rules specifying permitted sequences of changes of state of some structure. Such rules may be expressed in many different syntactic forms, including the use of recursion, sub-routines, and other concepts found in high level programming languages. This is somewhat vague, but all attempts to make the notion more precise have so far produced formulations that can be proved to be mathematically equivalent to what can be specified in a Turing machine. Moreover, it is possible to prove that any function computed by a collection of Turing machines running (synchronously) in parallel can be modelled by a single Turing machine, by showing how the collection can be modelled on a single machine, e.g. by interleaving their operations. So, from a mathematical point of view, the concept of an algorithm is not things are very different. The fact that any function computed by a collection of Turing machines (synchronously) in parallel can also be computed by a single Turing machine, leaves open the question whether there are any other important properties, besides the function computed, that may be different in parallel and serial implementations. Speed differences are relatively uninteresting: they can be overcome in principle by speeding up the machine used for the serial implementation, though there may be physical limits to this. Other differences between parallel and serial implementations are deeper. Consider the control requirements for a collection of co-existing interacting sub-systems. It is sometimes possible to produce the required interactions on a single time-shared processor, by providing a collection of concurrent virtual machines, but virtual parallel processes on a single machine sometimes have slightly different causal powers from processes implemented on a collection of machines, even when they do compute the same input/output function. http://www.cs.bham.ac.uk/~sra/People/Stu/Sloman/#TheEmperors The Emperors Real Mind by Aaron Sloman Lengthy review/discussion of Penrose (The Emperors New Mind). This review appeared in the journal Artificial Intelligence Vol 56 Nos 2-3 August 1992, pages 355-396 Compressed Postscript 17. How can we think about infinite sets? There remains the question whether we have a non-logical, non-formal, way of specifying an infinite series? It may be that we do have ways of representing information that cannot be modelled with full precision on Turing machines or equivalent computational systems. Various authors (e.g. Sloaman [20], Funt [4] have suggested that there are methods of representing and manipulating information using pictures, maps, models and other formalisms that are distinct from Fregean or applicative formalisms to which the limit theorems of logic and computer science apply. Is there some way of representing the notion of the infinite set of integers that is different from the use of a formal system of the kind considered by Godel? Could we use a physical mechanism for generating numerals, i.e. representations of numbers, indefinitely? Is it possible that there is some way of perceiving properties of such a concrete numeral-generating mechanism that is different from a formal derivation or a digital computation? Some mathematicians seem to think that the mental operation of adding 1 is the basis of the grasp of the whole infinite series of natural numbers. Could this be based on something like perception of some kind of iterative mechanism and its properties? Perhaps such formalisms and mechanisms would have to play a role in the thought processes of a robot mathematician with human capabilities. Until it is demonstrated that we do have some way of completely specifying exactly which infinite set we are talking about as a model of F then it is not the case that we can claim to have seen that G(F) is true: for it will actually be false in some models of F and we have no basis for saying that our grasp of the intended model rules this out. At present it is totally unclear what such a method of determining the intended model could be like, except that Godels theorem shows that no axiom system or algorithmic method suffices, as Penrose correctly points out. 18. Mathematical Platonism Penrose makes much of mathematical Platonism, claiming that certain mathematical entities, such as the natural number series and the Mandlebrot set, exist independently of us, and that we can somehow discover truths about them. His Platonism has exasperated some critics who regard it as a metaphysical or mystical nonsense. For Penrose, however, it plays a crucial role in explaining how we discover facts like the truth of G(F). He thinks that we have some kind of direct contact with these entities, which enables us to grasp statements about them. Some Platonists (e.g. Plato?) claim that if mathematical entities exist in a special non-physical realm then the discovery of mathematical truths must employ special spiritual mechanisms that enable such entities to be explored. This would pose a real threat to the long term aims of AI as a discipline committed to the use of mechanisms wholly embedded in the physical world. However, Penrose does not construe Platonism in this extreme anti-physicalist form. In particular, he does not believe that the brains of mathematicians depend on anything that is in principle beyond the reach of physics. All he is claiming is that mathematical truths and concepts exist independently of mathematicians, and they are discovered not invented. This, I believe, deprives Platonism of any content, and certainly leaves it as no threat to AI. Despite the effort Penrose puts into his defence of mathematical Platonism, and the strong counter-claims of others that it is a mystical, or anti-scientific doctrine, such disagreements are really empty. It makes not a whit of difference to anything whether the Mandlebrot set, or the natural natural number series, does or does not exist prior to our discovering them. The dispute, like so many in philosophy, depends on the mistaken assumption that there is a clearly defined concept (in this case existence of mathematical objects) that can be used to formulate a question with a definite answer. We all know what it means to say that a unicorn (defined as a horse with a single horn) exists, and we know how to investigate whether that is true or false. Quite different procedures are involved in checking the equally intelligible question whether there exists a prime number beteween two given integers N1 and N2. But there is no reason to assume that any clear content is expressed by the question whether all the integers do or do not Ôreally exist, or exist independently of whether we study them or not. For example, this cannot make any difference to the design requirements for mathematical intelligence. The practice of mathematics, the process of explorationa and conjecture, the nature of proof, the devastating effect of counter-exampless, would all be the same no matter whether entities exist in advance of discovery or not. Intuitionists have argued that because mathematical objects have no independent existence certain methods of proof, e.g. those using ~ ~p --> p are not valid. But other mathematicians have happily gone on ignoring this stricture without any disastrous consequences. Mathematics is a subject in which different classes of things can be studied and different methods of reasoning can be explored. Once a method is well specified we can then find out what can and what cannot be done with it. Arguing that one is right and another wrong because certain things do or do not exist is pointless when the relevant notion of existence in question is so ill-defined. I conclude that the question whether Platonism is true is just one of those essentially empty philosophical questions that have an aura of profundity, like Where exactly is the Universe? or How fast does time really ßow? An intelligent machine, like many intelligent human beings, may be tempted to misconstrue such questions as having significance, but they provide no basis for doubting the possibility of intelligent machines. .... There is, however, a real problem here, which can be put in much more straightforward language by stating that many mathematicians and others claim to think about and communicate about types of abstract objects that cannot easily be specified by giving examples, and which need some kind of indirect identification. One of the oldest examples is the infinite set of natural numbers, or even the infinite set of numerals denoting them. We can easily present examples of increasingly large subsets, but never the whole thing. Immanual Kant [8] claimed many years ago that such infinite totalities can only be grasped via rules that generate them, and this is widely believed. But, as Ive explained above, if the rules are specified in something like a formal syste, Godels incompleteness theorem shows that there is a problem about whether the intended set can be specified completely. Unless there is some important undiscovered mechanism for such thinking, all those mathematicians are fooling themselves, not about the particular theorems they prove, but about the nature of their understanding. If so that suggests that artificial intelligences may fall into the same trap. If every method of specifying infinite sets is equivalent to the use fo a formal axiom system, then Godels theorem, far from proving the impossibility of artificial intelligence, is a pointer to some limitations of intelligence in general. > ever discuss foundational issues with those who cannot question the > assumptions of their favorite school of thought? I dont have a side especially. I think it is poorly defined philosophical issue which has lasted this long just because of lack of definitions. I think infinities are used in quantum theory calculations. I dont think whether the infinities are actual or potential changes the outcome of a calculation. > What I explained to a slightly confused mathematician who believed > himself to be a constructivist was that a sane analysis in philosophy > of computation suggests that Turing Machines should be thought of > physical devices, if we are to remain physicalists. This is rather bizarre. To remain a physicalist think of a PC as physical because it is. Do you think physicalists should not have abstract thoughts? TMs are abstract devices, conceptions. Because TMs share some functional properties with the output of PCs does not confer non-physical abstract properties that are used in the definition of a TM. >You do not > challenge any of the arguments. Instead, you assert things, like > saying that Turing Machines are not of this world. Show us that > world, or is it the fairy-land of mathematics? I challenged your arguments by presenting definitions which you call assertions. I said there are abstract ideas. A Turing machine is an abstract idea. Do you deny there are abstract ideas?? Do you deny that there are ideas?? Are ideas physical so that you can capture one, put it in a jar? Our brain processes provide our ideas. That does not mean that the content of the idea is physically real. What is imagined, such as counterfactuals or unicorns does not need to physically exist (the product of our abstract thinking) just because there is an underlying physical process in the brain creating thought. Do you find thought experiments useless because the object of the thought experiment does not physically exist? > [snip some philosophy] > Amused, Well, they say ignorance is bliss. Have you ever done a Google search and seen the definitions of a Turing Machine? http://en.wikipedia.org/wiki/Turing_machine The Turing machine is an abstract model of computer execution and storage introduced in 1936 by Alan Turing to give a mathematically precise definition of algorithm or Ômechanical procedure. As such it is still widely used in theoretical computer science, especially in complexity theory and the theory of computation. The thesis that states that Turing machines indeed capture the informal notion of effective or mechanical method in logic and mathematics is known as the Church-Turing thesis. A theoretical model of a computing device, devised by Alan Turing. www.rsasecurity.com/rsalabs/faq/B.html A form of universal computer, assumed to take its instructions from an infinite paper punched tape and output results to the same medium before stopping upon completion of the program. [SH: This infinite medium is never presumed to have actual physical existence. Turings machine was a thought experiment that used an imaginary condition. I doubt that because there is no physical actually infinitely long tape that this has anything to do with Cantors discussion of potential and actual infinities in set theory. Cantor is not saying abstract infinities potential or acutal are real world. I dont think the ideas are connected except in your mind.] www.calresco.org/glossary.htm A hypothetical computing device, invented by Alan Turing in 1936, used to study the nature of algorithms and computation. [SH: **hypothetical**] cs.uhh.hawaii.edu/cs/courses/cs100/glossary.htm a hypothetical computer with an infinitely long memory tape www.cogsci.princeton.edu/cgi-bin/webwn Alan Turings definition of a Turing machine was not intended as a blueprint for how one would actually build practical computing machinery. SH: In the real world this would practically be too slow. In another respect, it is not possible to build a Turing machine because Turing gave the TM a potentially infinitely long tape. No PC has access to infinite memory because the resources of the universe are not potentially infinite, they are finite. Because memory can be added to a PC so that it can solve a great many of the problems that a TM is capable of solving does not make them fully equivalent in computational power. Remember, that does not mean speed of calculation. Yes, there are a great many similarities between a TM and a PC. But the precise similarity between a potentially infinitely long tape of a TM and the physical memory of a PC does not exist. And that is by far the most important link, if you try to compare Cantors usage of infinity with TM infinity. PCs dont have an anything infinite nor unbounded finiteness. The universe is a bounded physical memory resource. 1 idea : a transcendent entity that is a real pattern of which existing things are imperfect representations b : a standard of perfection : IDEAL 3 abstract : dealing with a subject in its abstract aspects : THEORETICAL 3 : theoretical: existing only in theory : HYPOTHETICAL 2 : hypothetical/hypothesis a tentative assumption made in order to draw out and test its logical or empirical consequences > -- > Eray Ozkural > [*] And you might as well say, our language expressions do not need > to refer to physically plausible things. Then, you should perhaps > think of defending that we freely talk of God in scientific discourse. > But that is not permissible in scientific talk. Maybe it is good for > mythology, which is not our business. Who is talking about God?? You are claiming that actual infinities, which have no physical implication, are theological constructs. You are using the idea as theologians used it, not Cantor. Again, Cantor and or Godel belief in mathematical platonism is not necessary to establish the existence of set theory or incompleteness. Just because Cantor was a Platonist does not mean his usage creation of set theory and actual infinities requires a belief in mathematical platonism! There are millions of mathematicians who are not Platonists that accept godelian incompleteness and set theory using Ôcompleted infinity. You write like you think platonism is a necessary requirement to understanding set theory. >You do not > challenge any of the arguments. Instead, you assert things, like > saying that Turing Machines are not of this world. Show us that > world, or is it the fairy-land of mathematics? SH: Of course I assert this because it is a fact. You lose credibility when you so emphatically announce misunderstanding something this basic. Your arguments dont make sense when your basic premise is wrong. PCs are not like TMs in precisely the area which has application to Cantor and infinities. TMs have an infinite property and PCs dont. Adding the universes memory to a PC just moves its capacity up, but it is still finite, not any type infinity under discussion in this thread. Cantor does his abstraction on a potential infinitiy ---> actual infinity. PCs have a universe with finite resources, not potentially infinite, and using all the universe as a memory source does not become/achieve infinity. I cant see how bringing finite TMs into this issue, just because they are practical is useful at all. The issue being discussed is not practical/physical but theoretical, hypothetical and abstract; an idea not a physical thing. I suppose I should edit this and shorten it. But Im not willing to spend any more time on this. Andrew Hodges took a bit too much poetic license. Stephen === Subject: Re: Turing Machines and Physical Computation quoted, in part: >Unless there >is some important undiscovered mechanism for such thinking, all those >mathematicians are fooling themselves, not about the particular theorems >they prove, but about the nature of their understanding. If so that suggests >that artificial intelligences may fall into the same trap. If every method >specifying infinite sets is equivalent to the use fo a formal axiom system, >then >Godels theorem, far from proving the impossibility of artificial >intelligence, >is a pointer to some limitations of intelligence in general. Although there are many true theorems that any given mathematician may never prove, the reasons are generally due to limitations of powers and knowledge. Since there are many things that will need to be discovered before artificial intelligences equivalent to human intelligence can be constructed, I see no reason to fear that a limitation on formal systems is also a limitation on minds - natural or artificial. John Savard http://home.ecn.ab.ca/~jsavard/index.html === Subject: Re: Turing Machines and Physical Computation > Hi Stephen, > I would have expected a thoughtful reply. > I gave you a factual reply. It doesnt take all that much thought > because Ive already learned the definitions and been over this before, > sometimes in your position, having misconceptions. You are missing the entire point that computation is meant to be a physical process. That is all there is to computation. It is a theory of computing machines. And it describes a large number of them. Lets get down to your particular objections to my detailed analysis. An analysis of your first response shall suffice. >> I have had such a discussion with an extremely intelligent and >> experienced mathematician. He told me that PCs are not Turing >> Machines, because they have an infinite tape. I think he did not >> know anything about descriptive complexity. This infinite portion of >> the tape consists entirely of blank symbols, and therefore has >> descriptive complexity O(1), which is easily realized by a physical >> system. When I told him about Ullmans indefinite growing argument, he >> objected But when the universe is filled up, it cannot grow any more! >> Then, it is not infinite, to which I responded Yes, but there is >> *nothing* that is larger than the universe. To assume the contrary >> would be theology, which I despise. >> Turing Machines are idealized which means they are not physically >> realized. > What a nice assertion. > It is a fact. I dont think you understand your presupposition that runs underneath your fact. You are presupposing that (Ideal -> Immaterial) If a concept is idealized, it does not describe any part of physical reality. This is a quite bad presupposition. I urge you to reveal from whom you gathered such a misconception. (Or otherwise, make some ordinary philosophy of language, to disprove that the above stated principle is inherent in your answer. Either way, your argument cannot be maintained as I try to show below.) > I dont know how you missed this. A TM can be simulated, > parts of its description realized, on a physical computer. > But not the part that allows unbounded resources. Really. > The physical resources of the > universe could be converted to physical memory for a computer and > eventually would not suffice to match the resources of a Turing Machine. What a trivial observation. You mean, the theory contains *descriptions* of machines that cannot be constructed. That is all there is to what you are saying, and it makes perfect sense for many *general* theories. > A TM is a theoretical machine that can compute some number X, which > could not be contained if the physical universe down to sub-atomic Stephen, about this issue you are completely misguided. A physicalist philosophy of computation restricts discrete computation to computation of finite entities. Some process that *actually* outputs an infinite string is NO COMPUTATION. That is why computability in the limit has this strange notion of a sequence of bounded computations which seems to escape your reason. (Yes, I think there is a metaphysical reason for insisting on such a definition, and its a correct one!) I dont think you truly understand my basic arguments. You are still claiming, in spite of many explanations I have made to you over the course of the last couple of years, that a A Turing Machine can calculate Pi, but a PC cannot. Why do you still assert such a blatantly wrong statement? You may have thought you *found* something, but I will have to disagree. Your PC can calculate Pi, exactly in the same quality the theory of computation predicts. And that is all that we can ever say about the computability of Pi. Since the number Pi, by definition is not something that can physically exist (for all we know about quantum theory...), only approximations to this metaphysical idea can be mechanized. And Turing Machine makes this notion of mechanization explicit, thats all. Turing Machine is only one of several equivalent specifications of computation. Infinite space, as a construction component, occurs in none of the other models, hence it should be understood, even by those who have difficulty in abstracting from Turing Machine to any computer, that the infinite tape part of Turings description entails NO NECESSARY CONDITION for computing machinery in general. Recall, dear Stephen, that Turing was exclusively concerned with Computing MACHINERY. Machinery has a very specific meaning, it means physical, mechanical devices. If your presupposition held, then Machinery would mean something else, like angels, or deities. Turing knew exactly what Machinery meant, but this most elementary concept in philosophy of computation is alien to you, and unfortunately I suspect to many others on these forums. The only relief I take is that Ullman et al. agree with me, in that they believe PCs are indeed Turing Machines. And this is no surprise. Any sensible computer scientist would know that. Only mathematicians and philosophers would claim otherwise. But every couple of months, a naive mathematician will show up (not you) and try to purport an imaginery dichotomy between physical computation and Turing computation. That is unfortunate, very unfortunate indeed, because in my opinion it shows a systematic mental error. It is the shadow of Cartesian Dualism which bothers me, Stephen, and I am certain that you do not appreciate how tight the coupling is. In general, I call this issue the software/hardware dichotomy, and I believe I showed it to be equivalent to substance dualism. It is just a naive application of Platos theory (which Plato himself would probably not approve of) to modern terms. I will dub this more specific, and in my opinion more catastrophic case, the physical/Turing computation dichotomy. It is unfortunate, because it presupposes that two kinds of machines exist: material and immaterial. However, a closer physicalist analysis as mine rigorously reveals that it is nonsense to talk of immaterial machines, otherwise we would bring all the demons of the medieval ages together with these immaterial machines. Immaterial machine is an oxymoron, because there is NO IMMATERIAL PLANE. I believe I am making it very clear what is at stake. In contemporary philosophical circles, there seem to be some people who hold the idea of these uncomputable things akin to the idea of God, or that we have such a theory is in fact an implicit ontological argument for the existence of God. [*] That would be *just* as silly as saying that the existence of the Bible is a proof of the existence of God. As an opponent of God, I do not allow such ideas to slip in. If you do not want to discuss your assumptions in more detail, we can stop discussing. Ive made my position clear. We can draw the borders clearly and tell the audience where the ideas diverge. That much is sufficient for me. Cordially, -- Eray Ozkural [*] I dont know what Chaitin really thinks, but I would be delighted if he made an explanation. I believe he would agree with me, because he is a sensible computer scientist. PS: I dont think your argument from dimensionality strengthens the validity of your Ideal -> Immaterial assumption. That is no such thing. Similar arguments were advanced by neo-physicalists, but I dont think dimensionality makes a great difference. We can safely abstract away from the actual dimensionality of our universe, WHICH WE DO NOT KNOW. === Subject: Re: Turing Machines and Physical Computation >You are missing the entire point that computation is meant to be a >physical process. That is all there is to computation. It is a theory >of computing machines. And it describes a large number of them. Lets >get down to your particular objections to my detailed analysis. >But every couple of months, a naive mathematician will show up (not >you) and try to purport an imaginery dichotomy between physical >computation and Turing computation. That is unfortunate, very >unfortunate indeed, because in my opinion it shows a systematic mental >error. Although a theory of physical computing machines is possible, we do not have such a theory as yet. The Turing Machine, as A. M. Turing specified it, cannot calculate pi, but it can calculate any finite number of digits of pi, such as (10^(10^(10^(10^(10^1000))))) digits of pi, even though no physically-realizable computer could calculate that many digits of pi. Turing _did_ specify the Turing machine that way, so it is a fact that he made the same systematic mental error you refer to. Why did he do such a thing? Because it made it possible for him to derive results from his theory in a reasonable amount of time. Determining what the limits of computation in the physical universe are, and what can be done within those limits, is a very complicated problem. Assuming infinite memory capacity is a simplifying assumption that makes for a theory much easier to derive and work with. What is the use of such a theory, a theory that doesnt refer to the real world? If certain things cannot be done with even an infinite memory, then they cannot be done with a finite memory. And many things that can be computed dont need an infinite amount of memory, or even an absurdly large finite one. So the Turing machine is an *approximation* to a real computing machine. lines made with real pencils and the pinpricks made by the point of a real compass, mathematicians have always approximated the real world by abstractions which are not physically realizable. This makes the symbolic manipulations in mathematics simpler - and thus makes them realizable instead of impractical. Giving this up would mean giving up mathematics, because taking into account the limitations of the real world in every case would make many fields far too complicated to investigate. John Savard http://home.ecn.ab.ca/~jsavard/index.html === Subject: Re: Turing Machines and Physical Computation >lines made with real pencils and the pinpricks made by the point of a >real compass, mathematicians have always approximated the real world by >abstractions which are not physically realizable. Well, I dont know about that. Whose theory is this? I thought most mathematicians who expressed an opinion were generally some sort of Platonists, believing that effective mathematics is discovered, not invented, and that it is the real world which approximates the ideal. In any case, I would disagree with it, in the name of a nominalist, instrumentalist theory that focuses on the agent doing the computing, and not on the approximations of reality to a model, or vice-versa, as the case may be. Its a violent rearrangement of fundamentals for most people, but try it sometime! J. === Subject: Re: Turing Machines and Physical Computation >>lines made with real pencils and the pinpricks made by the point of a >>real compass, mathematicians have always approximated the real world by >>abstractions which are not physically realizable. >Well, I dont know about that. Whose theory is this? I thought most >mathematicians who expressed an opinion were generally some sort of >Platonists, believing that effective mathematics is discovered, not >invented, and that it is the real world which approximates the ideal. Both real and ideal worlds are discovered and invented. Neither is the other; they approximate each other. Its my theory. >In any case, I would disagree with it, in the name of a nominalist, >instrumentalist theory that focuses on the agent doing the computing, >and not on the approximations of reality to a model, or vice-versa, as >the case may be. >Its a violent rearrangement of fundamentals for most people, but try >it sometime! === Subject: Re: Turing Machines and Physical Computation >>lines made with real pencils and the pinpricks made by the point of a >>real compass, mathematicians have always approximated the real world by >>abstractions which are not physically realizable. > Well, I dont know about that. Whose theory is this? I thought most > mathematicians who expressed an opinion were generally some sort of > Platonists, believing that effective mathematics is discovered, not > invented, and that it is the real world which approximates the ideal. > In any case, I would disagree with it, in the name of a nominalist, > instrumentalist theory that focuses on the agent doing the computing, > and not on the approximations of reality to a model, or vice-versa, as > the case may be. Well, I can see how it is possible to see how nominalism has a bearing on this. Im going to append a quote by Anders Weinstein. Mostly, people do not endorse mathematical platonism which means mathematics pre-exists and is discovered in another realm by the mathematician. But a conventional view, that mathematics is invented still describes mathematical objects, such as i, the square root of -1, or the infinity of dimensionless points on a number line as abstract ideas not concrete physical things. The definitions are not tied into Platonism (P) so that one can make an analogy to abstract mythical realms due to P. > Its a violent rearrangement of fundamentals for most people, but try > it sometime! > J. They teach you in school that a number line is composed of a series of dimensionless points, neither of which has physical existence. All physical things have dimension. A point you make with a pencil is not a point that corresponds to a mathematical point on a number line because the point created by a pencil has dimension. But I can see how nominalism could point to a pencil point as a physical expression of point, rather than a mathematical concept. I dont think nominalism can help in this tape discussion. Turing did in fact use an abstract approach in his paper which does not have a foothold in the physical world. There is no physical correlate to his endless tape. (He states that the TM can compute Pi which is an infinite limit.) Turing says one can substitute a _one-dimensional_ tape that can have symbols printed on it from an infinite ink supply. There are aspects of this logical computing machine that can be physically represented, but not the tape. Nor is there any mention of any time constraint. The reason the TM is described as hypothetical or an abstraction is because that is how Turing presents it. I dont see evidence of his adopting a philosophy, such as nominalism, anywhere in the 1936 paper. I dont see how stating that he could have done this and that it might have been legitimate denial of abstraction presents any evidence that he did do this or that he thought this way. I think he tried to make his paper tangibly clear. And his paper seems much more intuitively understandable than Godels to many people. The idea of building a physical computer came later after working on Enigma. Once upon a time, some philosophers like Nelson Goodman explored a program they called nominalism. They wanted to analyze away *all* putative reference to abstract entities. This included propositions, but also such things as patterns or words (as types) or letters (as types). They did this by offering to paraphrase them away via reference to concrete exemplars and use of equivalence relations. reference to some abstract object, they would try to analyze it as: John made some inscription which is a replica of (or cotypical with) this one followed by reference to another concrete inscription. So they hoped to trade in abstract *objects*, although they still employed a variety of equivalence relations. There are various technical objections to this, e.g. it cannot obviously handle reference to expressions, the name of God, perhaps, that are never actually inscribed. (You can talk about unactualized possible inscriptions, but they are also taboo for the nominalist). jumped ship, and accepted abstract objects as irreducible in science. So for Quine, there is no real problem about propositions due to their abstractness -- just define them as equivalence classes of synonymous expressions. The problem is in the similarity relation. But others think there is some advantage. They think at least that it helps avoid a mythology of abstract objects, independent of the human world. Rather, we should recognize that a meaning is something always expressed in *signs*, which have a foothold in the concrete, spatio-temporal world. === Subject: Re: Turing Machines and Physical Computation >But others think there is some advantage. They think at least that >it helps avoid a mythology of abstract objects, independent of the human >world. Rather, we should recognize that a meaning is something always >expressed in *signs*, which have a foothold in the concrete, spatio-temporal >world. Not to give a primer on nominalism itself, of which there are endless varieties, and the kind I prefer is pretty far off to one side, but the point is that in talking about AI, one possible approach, and the only one Im interested in, focuses on how it is an agent can have anything remotely like intelligence. With the focus on the agent, one classically gets into questions of epistemology rather than ontology, language rather than physics. Nominalism(s) are about the effective use of signs and symbols with the least possible commitments to facts about the world. It blends naturally with the methodological solipsism which is characteristic of any discussions of computation. J. === Subject: Re: Turing Machines and Physical Computation <419c4735$0$44080$5fc3050@dreader2.news.tiscali.nl> <419cd7d4$0$44068$5fc3050@dreader2.news.tiscali.nl> <4zrnd.46389$QJ3.16198@newssvr21.news.prodigy.com> <41a0f0ff.2213961@news.ecn.ab.ca> <7a68q0tortpkm6dlj983kgg4kvlpgrbapa@4ax.com> real compass, mathematicians have always approximated the real world by >abstractions which are not physically realizable. >> Well, I dont know about that. Whose theory is this? I thought most >> mathematicians who expressed an opinion were generally some sort of >> Platonists, believing that effective mathematics is discovered, not >> invented, and that it is the real world which approximates the ideal. >> In any case, I would disagree with it, in the name of a nominalist, >> instrumentalist theory that focuses on the agent doing the computing, >> and not on the approximations of reality to a model, or vice-versa, as >> the case may be. >Well, I can see how it is possible to see how nominalism has a bearing >on this. Im going to append a quote by Anders Weinstein. >Mostly, people do not endorse mathematical platonism which means >mathematics pre-exists and is discovered in another realm by the >mathematician. But a conventional view, that mathematics is invented >still describes mathematical objects, such as i, the square root of -1, or >the infinity of dimensionless points on a number line as abstract ideas not >concrete physical things. The definitions are not tied into Platonism (P) >so that one can make an analogy to abstract mythical realms due to P. >> Its a violent rearrangement of fundamentals for most people, but try >> it sometime! >> J. >They teach you in school that a number line is composed of a >series of dimensionless points, neither of which has physical existence. >All physical things have dimension. A point you make with a pencil is not >a point that corresponds to a mathematical point on a number line >because the point created by a pencil has dimension. But I can see how >nominalism could point to a pencil point as a physical expression of point, >rather than a mathematical concept. >I dont think nominalism can help in this tape discussion. Turing did in >fact >use an abstract approach in his paper which does not have a foothold in >the physical world. There is no physical correlate to his endless tape. >(He states that the TM can compute Pi which is an infinite limit.) >Turing says one can substitute a _one-dimensional_ tape that can have >symbols printed on it from an infinite ink supply. There are aspects of >this logical computing machine that can be physically represented, but >not the tape. Nor is there any mention of any time constraint. The reason >the TM is described as hypothetical or an abstraction is because that >is how Turing presents it. I dont see evidence of his adopting a >philosophy, >such as nominalism, anywhere in the 1936 paper. I dont see how stating >that he could have done this and that it might have been legitimate denial >of abstraction presents any evidence that he did do this or that he thought >this way. I think he tried to make his paper tangibly clear. And his paper >seems >much more intuitively understandable than Godels to many people. The >idea of building a physical computer came later after working on Enigma. >Once upon a time, some philosophers like Nelson Goodman explored a >program they called nominalism. They wanted to analyze away *all* >putative reference to abstract entities. This included propositions, >but also such things as patterns or words (as types) or letters (as >types). They did this by offering to paraphrase them away via reference >to concrete exemplars and use of equivalence relations. >reference to some abstract object, they would try to analyze it as: >John made some inscription which is a replica of (or cotypical with) >this one followed by reference to another concrete inscription. >So they hoped to trade in abstract *objects*, although they still >employed a variety of equivalence relations. >There are various technical objections to this, e.g. it cannot obviously >handle reference to expressions, the name of God, perhaps, that are never >actually inscribed. (You can talk about unactualized possible inscriptions, >but they are also taboo for the nominalist). >jumped ship, and accepted abstract objects as irreducible in science. >So for Quine, there is no real problem about propositions due to >their abstractness -- just define them as equivalence classes of >synonymous expressions. The problem is in the similarity relation. >But others think there is some advantage. They think at least that >it helps avoid a mythology of abstract objects, independent of the human >world. Rather, we should recognize that a meaning is something always >expressed in *signs*, which have a foothold in the concrete, spatio-temporal >world. misleading and requires one to understand the modus vivendi and pragmatic nature of the double standard or anomalous monism. Quines extensionlism renders much of the above talk of nominalism redundant metaphysics. But to understand that, *you* would have to show a little more respect for what you have been criticised for and an even greater willingness to listen instead of presume. -- David Longley === Subject: Re: Platonism >>I thought most >>mathematicians who expressed an opinion were generally some sort of >>Platonists, believing that effective mathematics is discovered, not >>invented, and that it is the real world which approximates the ideal. ... > Mostly, people do not endorse mathematical platonism which means > mathematics pre-exists and is discovered in another realm by the > mathematician. I disagree ... sort of. People is a bit too broad. I was under the impression that mathematicians are naively platonistic, in that, without giving too much thought to it, they consider all the things they work with as real as anything a mechanical engineer works with. But for those mathematician who care about philosophy, they are split between those who think that platonism is totally discredited, and those who accept a weak form of it (realism or naturalism). -- Mitch Harris (remove q to reply) === Subject: Re: Platonism > .... I was under the > impression that mathematicians are naively platonistic, in that, > without giving too much thought to it, they consider all the things > they work with as real as anything a mechanical engineer works with. > But for those mathematician who care about philosophy, they are split > between those who think that platonism is totally discredited, and > those who accept a weak form of it (realism or naturalism). === > Subject: Re: What is a function? > .... > .... Still, does thinking of an ordered pair as of a > typographically ordered string of symbols suffice? Is that what > real mathies do, I mean, really, is that all there is to it? No, > I shouldnt think so. > As Im sure you know, the strings of symbols are used in the syntax of > formal theories. However, you seem to be more interested in > mathematical intuition or even philosophy, when you ask Is that what > real mathies do, I mean, really .... > .... having thought about it quite a lot over the years, I believe that > the day-to-day intuitive thinking of most mathematicians is different. > We very much tend to be relative Platonists. Let me explain that. > First, heres my view of the question whether mathematics is discovered > or invented. In principle, a mathematical theory can be set up on any > consistent axiomatic basis (although in practice, long historical > developments of ideas lead to the most fruitful sets of axioms). But > _after_ that, mathematicians have the job of exploring the > consequences: proving theorems and finding interesting examples (models > of the theory). So after _inventing_ an axiomatic system, we must > _discover_ its consequences. For example, after inventing the axioms > of group theory, we are left with the endless and fascinating job of > discovering all about groups. > Working within such an established theory certainly _feels_ Platonic. > Consequences of the axioms seem to be out there waiting to be > discovered, and we often struggle to find them. > In that context, my answer to your question would be that my intuition > of ordered pairs involves two mental objects which seem real in some > way, and I know which is first and which is second. But handling them > depends heavily on writing down pairs of symbols, because the > _language_ of mathematics is primarily written and not spoken (an > important point not often mentioned). My mind needs to feed on the > written symbols, certainly if they are to be manipulated much.... > Ken Pledger. === Subject: Re: Platonism >>I thought most >>mathematicians who expressed an opinion were generally some sort of >>Platonists, believing that effective mathematics is discovered, not >>invented, and that it is the real world which approximates the ideal. > ... > Mostly, people do not endorse mathematical platonism which means > mathematics pre-exists and is discovered in another realm by the > mathematician. > I disagree ... sort of. People is a bit too broad. I was under the > impression that mathematicians are naively platonistic, in that, > without giving too much thought to it, they consider all the things > they work with as real as anything a mechanical engineer works with. > But for those mathematician who care about philosophy, they are split > between those who think that platonism is totally discredited, and > those who accept a weak form of it (realism or naturalism). I agree. However, as evidenced by this newsgroup most mathematicians are naive platonists. They dont understand the distinction between the reality of a table and mathematical ideas. Godel claimed that there was no distinction. Godel was not naive. Actually, some of his arguments are quite strong. But he was wrong about that, in my opinion, and I also think you cant argue for mathematical platonism without also arguing against a mechanical mind, or arguing for the existence of a mathematical god. -- Eray Ozkural === Subject: Re: Platonism >>I was under the impression that (in general) >> mathematicians are naively platonistic, in that, >>without giving too much thought to it, they consider all the things >>they work with as real as anything a mechanical engineer works with. >>But for those mathematician who care about philosophy, they are split >>between those who think that platonism is totally discredited, and >>those who accept a weak form of it (realism or naturalism). > I agree. However, as evidenced by this newsgroup most mathematicians > are naive platonists. How does the anecdote go? On weekdays Im a platonist, but on the weekend Im a formalist ? > They dont understand the distinction between > the reality of a table and mathematical ideas. That is a bit strong. understand? maybe they dont -care-. or maybe it is more important to them the similarities. > Godel claimed that there was no distinction. Godel was not naive. > Actually, some of his arguments are quite strong. But he was wrong > about that, in my opinion, and I also think you cant argue for > mathematical platonism without also arguing against a mechanical mind, > or arguing for the existence of a mathematical god. I dont see the against a mechanical mind connection. As to a god, maybe Einsteins Spinozas God. -- Mitch Harris (remove q to reply) === Subject: Re: Platonism > Godel claimed that there was no distinction. Godel was not naive. > Actually, some of his arguments are quite strong. But he was wrong > about that, in my opinion, and I also think you cant argue for > mathematical platonism without also arguing against a mechanical mind, > or arguing for the existence of a mathematical god. > I dont see the against a mechanical mind connection. > As to a god, maybe Einsteins Spinozas God. The mathematical God could indeed be the One and the Infinite God in Spinozaa metaphysics. (And similar stuff is also in Leibniz), and since Spinoza is considered a neo-Platonist, I could accept this remark, accept that I do not know what neo-Platonist really means. It does not seem too far from Godels ideas. In Godels world, there would be a realm of mathematical objects even if our universe happened to be finite (he has separate arguments for that) No reason why I should not call that a part of God, but its probably different from Spinozas God, I presume, although there is also some similarity, I think Godel was careful enough to allow for Spinozas monism. Interesting relations that deserve more reßection. In particular, Godel allows for the possibility that the mind is mechanical, but in that case something awful happens that upsets the materialists. -- Eray Ozkural === Subject: Re: Platonism >>I was under the impression that > (in general) >> mathematicians are naively platonistic, in that, >>without giving too much thought to it, they consider all the things >>they work with as real as anything a mechanical engineer works with. >>But for those mathematician who care about philosophy, they are split >>between those who think that platonism is totally discredited, and >>those who accept a weak form of it (realism or naturalism). I agree. However, as evidenced by this newsgroup most mathematicians > are naive platonists. > How does the anecdote go? On weekdays Im a platonist, but on the > weekend Im a formalist ? Yes, I think Ive heard this quote often. Maybe it serves to illustrate that most mathematicians dont even care about these incompatible positions. > They dont understand the distinction between > the reality of a table and mathematical ideas. > That is a bit strong. understand? maybe they dont -care-. or maybe > it is more important to them the similarities. Most mathematicians dont care, and many of which do not care probably do not have enough motivation to know either. The ones who care probably understand much better than the rest. :) Maybe, they wouldnt subscribe to any position, but they would know what each prominent position actually means philosophically. > Godel claimed that there was no distinction. Godel was not naive. > Actually, some of his arguments are quite strong. But he was wrong > about that, in my opinion, and I also think you cant argue for > mathematical platonism without also arguing against a mechanical mind, > or arguing for the existence of a mathematical god. > I dont see the against a mechanical mind connection. This is an almost direct paraphrasing of Godels disjunctive proposition! I have added nearly nothing to it, except for the word god. We can talk about it further. I think Godel was the only philosophically rigorous mathematical Platonist. Except him, its just a lot of handwaving and make-belief. He was intelligent enough to present a detailed and quite strong argument that mathematical objects have an independent existence, just like your keyboard. > As to a god, maybe Einsteins Spinozas God. Maybe. I dont know if Einstein was a Platonist. Was Spinozas pantheism a kind of Platonism? I dont know, Ill have to read Spinoza directly to answer that. -- Eray Ozkural === Subject: Re: Platonism iD8DBQFBp6zwvmGe70vHPUMRAhFBAJ9V6kt8hWW87JD/ OCL7V3KFlv6URwCgyvXO u6Jcc7ig3oCVCpIjU7b01oE= =xg8+ >> How does the anecdote go? On weekdays Im a platonist, but on the >> weekend Im a formalist ? >Yes, I think Ive heard this quote often. Maybe it serves to >illustrate that most mathematicians dont even care about these >incompatible positions. They are not at all incompatible. === Subject: Re: Platonism iD8DBQFBpilFvmGe70vHPUMRAldOAKDBB6bTbyamr8N5Pe8u91dmm4dA5ACfRp sY 64nvtwl8dF351RKbSYs3YrY= =2wm+ >I agree. However, as evidenced by this newsgroup most mathematicians >are naive platonists. They dont understand the distinction between >the reality of a table and mathematical ideas. Nonsense! Of course mathematicians understand the distinction. === Subject: Re: Platonism >I agree. However, as evidenced by this newsgroup most mathematicians >are naive platonists. They dont understand the distinction between >the reality of a table and mathematical ideas. > Nonsense! Of course mathematicians understand the distinction. Well, I dont think most of them have even an inkling. Otherwise, they would stop suggesting that PCs are not models of Turing Machines, or that real numbers exist or other silly Platonism. In particular, they should acknowledge that consistency alone is no indication of reality. That is the issue. I can come up with a completely consistent, and a completely fabricated story, like the Bible. But that is a fairy tale. It is not real. Likewise, mathematicians can come up with consistent and un-real stories. Most mathematicians do not appreciate that whatever idea they can think about is not automatically real. In my opinion, most mathematicians think that real numbers existed before humanity. That is seen by their naive reliance on the strict truth of their assumptions about real numbers, and by the fact that they think it is clear what is real! They seem to think that real numbers have an independent existence than us! (Or sets or whatever) Then, it should follow, that mythology also has an independent existence, because, it is conceivable that a future tribe of monkeys could discover the same naive mythology! Neither do they understand that the immediate reality of mathematical ideas consist only and only in their becoming part of their subjective experience, and as shadows of their ideas in their written and spoken work, exactly in the same fashion as works of theology immediately persists such. Unless their reality is confirmed by empirical trials that extend beyond such an inadequate use, no mathematical idea is real. (Just like no dream is real) I can fantasize all that I want in other terms than mathematics. That is best seen in metaphysics. I can define terms, and some rules, and then describe a world built in these terms and rules. That does not mean that the world in question exists. Speech alone does not create a strong reality. I suggest that exists has always a physical meaning. (Neither do the complexity or difficulty of our fantasies make them mathematical! But that is another issue) If on the other hand, we are saying that mathematics is not concerned with this world, but with wildly different possible worlds, e.g. it is the same thing as metaphysics, then I dont believe that. I dont believe thats necessary. And I also think computation sets the limits to real mathematics. I admit that the views of this paragraph are controversial views, and I dont expect you to buy them. But the previous paragraphs are quite ordinary philosophy of mathematics. (And not some extremely naive logical positivist view) I suggest lets stop using those notorious skyhooks. In particular, I am making the following important claim, and I think you should think about it. Please tell me your opinion about it, because this is the principle (or one of principles) from which I derive the whole analysis. (Principle of ontological homogeneity) Mathematical statements have no ontological privilege. That is, when we are talking about existence, mathematical statements are absolutely no different than statements in any other language or framework. Using the word exists differently for arts, sciences, philosophy and mathematics, would be irresponsible, it would only show that we have no idea what exists means. The principle has no proof, thats what I think. It is equally dubious to say that integers exist, by the way. (So, Im not blindly following Kronecker or Chaitin) You have to give a philosophical explanation of why you think that is the case. Because *no mathematical explanation* can be ontologically adequate on its own, it seems that mathematics is merely symbol pushing when it comes to explaining these matters. Once you explain what you mean by the existence of integers, however, you can refer to this explanation and construct more complex ontological statements. (None of which can include God, naturally) That is in fact what we should do, and I think its been done fairly well for integers, but not well at all for real numbers... (And that is where I could agree with Kronecker) God is just an idea. It is not real. -- Eray Ozkural === Subject: Re: Platonism >I agree. However, as evidenced by this newsgroup most mathematicians >are naive platonists. They dont understand the distinction between >the reality of a table and mathematical ideas. >>Nonsense! Of course mathematicians understand the distinction. > Well, I dont think most of them have even an inkling. Otherwise, they > would stop suggesting that PCs are not models of Turing Machines, or > that real numbers exist or other silly Platonism. > In particular, they should acknowledge that consistency alone is no > indication of reality. That is the issue. I can come up with a > completely consistent, and a completely fabricated story, like the > Bible. But that is a fairy tale. It is not real. Likewise, > mathematicians can come up with consistent and un-real stories. Most > mathematicians do not appreciate that whatever idea they can think > about is not automatically real. This is a follow up to my previous posting on this matter. The semantics of language works such that if we refer to a thing it must exist in our interpretation (world or model). But if we want to restrain our interpretive world to be a bit more realistic (for some interpretation of realistic) we can choose a more restrictive criteria. As we do this we will be consigning references outside the chosen scope of the additional criteria to the nonsense heap. I would like to consider several kinds of interpretations (worlds or models) according to reasonable criteria for existence in those worlds ... working from one extreme to the other ... fictional worlds no - physical - things located in time/space no - effective - procedures exist for identification no - objective - can be verified by multiple agents mental worlds yes - physical - things located in time/space no - effective - procedures exist for identification no - objective - can be verified by multiple agents mathematical worlds no - physical - things located in time/space yes - effective - procedures exist for identification yes - objective - can be verified by multiple agents physical worlds yes - physical - things located in time/space yes - effective - procedures exist for identification yes - objective - can be verified by multiple agents Note that in all the worlds considered here, if things are effective they are also objective. Perhaps those are the same criteria, perhaps not; if not then we should be able to describe those worlds distinct from the ones i mentioned. Also note that in all cases we are talking about *things* in whatever kind of world of which we speak. We are not talking of the marks which stand for those things in some other world. For example the marks which comprise a work of fiction are not usually allowed to exist in the world created by the interpretation of those marks. Constructive comments and critique gladly accepted. patty === Subject: Re: Platonism >(Principle of ontological homogeneity) >Mathematical statements have no ontological privilege. That is, when >we are talking about existence, mathematical statements are >absolutely no different than statements in any other language or >framework. You will have to be more careful at phrasing the question/principle. Any physical collection of marks lacks privilege, doesnt even have a meaning, much less any ontological commitments, until and unless it is properly interpreted. On the other extreme, once it has been interpreted and its meaning and extensions evaluated, if it turns out to have pragmatic value, that is, if it turns out to be true, then perhaps it can be granted some additional label, which might be privilege, compared to not quite identical statements which do not evaluate truly. So, does this all support your principle, or not? J. === Subject: Re: Platonism >(Principle of ontological homogeneity) >Mathematical statements have no ontological privilege. That is, when >we are talking about existence, mathematical statements are >absolutely no different than statements in any other language or >framework. > You will have to be more careful at phrasing the question/principle. > Any physical collection of marks lacks privilege, doesnt even have > a meaning, much less any ontological commitments, until and unless it > is properly interpreted. > On the other extreme, once it has been interpreted and its meaning and > extensions evaluated, if it turns out to have pragmatic value, that > is, if it turns out to be true, then perhaps it can be granted some > additional label, which might be privilege, compared to not quite > identical statements which do not evaluate truly. > So, does this all support your principle, or not? I think it kind of undermines my principle if accepted. But Im not sure if existence, which is in my opinion always a physical matter, could change its meaning in any context of interpretation. In particular, Im not sure if it has anything to do with relativity of truth. Surely, a chair either exists or not, whatever interpretation we have of the chair. Now, if theologists could produce rhetoric as fast as Neil, they would say, well when we say God exists, we use it in another sense than you say a table exists, and we dont expect you to understand this sense because you are ignorant about theology. Only after you admit that this sense of existence should be accepted in its own right, will we decide to call you educated in matters of faith. (You know, those theologists would probably be burnt at the stake.) Well, I will have to insist that exists word must have a very very definite meaning. Otherwise, it is nonsense. If I am allowed to distort the meaning of exists every now and then, I will be able to talk of God and angels as if they existed, and that will be heresy for me: I am a physicalist. -- Eray Ozkural === Subject: Re: Platonism >Well, I will have to insist that exists word must have a very very >definite meaning. Go ahead and insist, then, it wont hurt anything. :) > Otherwise, it is nonsense. If I am allowed to >distort the meaning of exists every now and then, I will be able to >talk of God and angels as if they existed, and that will be heresy for >me: I am a physicalist. Well, me too, I think, but my physicalism relates only to the sub-domains of philosophy that I care about, those of cognition and language and computation. As far as cognitive agencies go, they may assume that things exist and make the appropriate ontological commitments, and then we can get on with the internal matters that we need to deal with, about how agencies do what they do, in a material world. But the question here was whether mathematical statements have privilege, and I was just pointing out two very different ways of interpreting the question. If you feel a need to insist there is only one way of understanding the question, well, I suppose youd have company, as when Russell asserted that false statements have no meaning. But for me, that unsoundly combines several domains of philosophy. J. === Subject: Re: Platonism >(Principle of ontological homogeneity) >Mathematical statements have no ontological privilege. That is, when >we are talking about existence, mathematical statements are >absolutely no different than statements in any other language or >framework. >>You will have to be more careful at phrasing the question/principle. >>Any physical collection of marks lacks privilege, doesnt even have >>a meaning, much less any ontological commitments, until and unless it >>is properly interpreted. >>On the other extreme, once it has been interpreted and its meaning and >>extensions evaluated, if it turns out to have pragmatic value, that >>is, if it turns out to be true, then perhaps it can be granted some >>additional label, which might be privilege, compared to not quite >>identical statements which do not evaluate truly. >>So, does this all support your principle, or not? > I think it kind of undermines my principle if accepted. But Im not > sure if existence, which is in my opinion always a physical matter, > could change its meaning in any context of interpretation. In > particular, Im not sure if it has anything to do with relativity of > truth. Surely, a chair either exists or not, whatever interpretation > we have of the chair. Well if we define existence as that which we can assign timespace coordinates (however approximate), then most of the abstractions that engineers use to make our world go suddenly have no ontological status. However if we define existence at that for which an effective, objective procedure can be performed, then we can allow these useful objects into our ontology. > Now, if theologists could produce rhetoric as fast as Neil, they would > say, well when we say God exists, we use it in another sense than > you say a table exists, and we dont expect you to understand this > sense because you are ignorant about theology. ... which does not meet my (new?) definition of existence unless you can write an effective procedure for theological matters that can be performed with the same result by any arbitrary individual. > Only after you admit > that this sense of existence should be accepted in its own right, will > we decide to call you educated in matters of faith. (You know, those > theologists would probably be burnt at the stake.) > Well, I will have to insist that exists word must have a very very > definite meaning. Otherwise, it is nonsense. If I am allowed to > distort the meaning of exists every now and then, I will be able to > talk of God and angels as if they existed, and that will be heresy for > me: I am a physicalist. Well i suppose it is your choice, but for you most of math, logic, semantics, economics, and ethics wont be making any sense. patty === Subject: Re: Platonism -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 >>I agree. However, as evidenced by this newsgroup most mathematicians >>are naive platonists. They dont understand the distinction between >>the reality of a table and mathematical ideas. >> Nonsense! Of course mathematicians understand the distinction. >Well, I dont think most of them have even an inkling. Otherwise, they >would stop suggesting that PCs are not models of Turing Machines, or >that real numbers exist or other silly Platonism. It is a mistake to assume that exist as used by mathematicians has the same meaning as it has when we talk of the existence of ordinary things. Likewise, mathematical usage of model is different from ordinary usage. >In particular, they should acknowledge that consistency alone is no >indication of reality. That is the issue. I can come up with a >completely consistent, and a completely fabricated story, like the >Bible. But that is a fairy tale. It is not real. This is not relevant to mathematics. > It is not real. Likewise, >mathematicians can come up with consistent and un-real stories. Thats your misunderstanding of mathematics. It is not a system of creative fiction. > Most >mathematicians do not appreciate that whatever idea they can think >about is not automatically real. Silly. You are confusing the mathematical sense of real with the ordinary meaning of the word. >In my opinion, most mathematicians think that real numbers existed >before humanity. Of course they existed. But thats in the mathematical sense of exist. In the ordinary meaning of exist, real numbers do not exist even today. > That is seen by their naive reliance on the strict >truth of their assumptions about real numbers, and by the fact that >they think it is clear what is real! It is clear that you are quite ignorant about mathematics, and apparently proud of your ignorance. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.3.91 (SunOS) iD8DBQFBp0SRvmGe70vHPUMRAnr4AKC9qYopJDJHd19IbZD9JkrWEDNn0ACeJK TT anLww/nZHmdOmIpVDrBGMig= =o9VK -----END PGP SIGNATURE----- === Subject: Re: Platonism Hi Neil, In short, does your position in philosophy of mathematics have a name? I found it quite interesting! Comments follow. > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 >>I agree. However, as evidenced by this newsgroup most mathematicians >>are naive platonists. They dont understand the distinction between >>the reality of a table and mathematical ideas. >> Nonsense! Of course mathematicians understand the distinction. >Well, I dont think most of them have even an inkling. Otherwise, they >would stop suggesting that PCs are not models of Turing Machines, or >that real numbers exist or other silly Platonism. > It is a mistake to assume that exist as used by mathematicians has > the same meaning as it has when we talk of the existence of ordinary > things. Likewise, mathematical usage of model is different from > ordinary usage. I actually like your point about model. But I cannot say if I like the point about exist. What is this sense used by *most* mathematicians then? Would you care to explain? [I dont say all, I say most in the above discussion.] I am hoping you do not mean that in (most!) mathematics consistency is identical to existence. That would be quite silly, would not it? >In particular, they should acknowledge that consistency alone is no >indication of reality. That is the issue. I can come up with a >completely consistent, and a completely fabricated story, like the >Bible. But that is a fairy tale. It is not real. > This is not relevant to mathematics. So in mathematics consistency does not entail existence. What causes something to mathematically exist then? > It is not real. Likewise, >mathematicians can come up with consistent and un-real stories. > Thats your misunderstanding of mathematics. It is not a system of > creative fiction. What kind of a system is it, then? > Most >mathematicians do not appreciate that whatever idea they can think >about is not automatically real. > Silly. You are confusing the mathematical sense of real with the > ordinary meaning of the word. So, this reality has an altogether different sense than reality. Good. So, this reality must be something else! I think when I say a mathematical object, I usually mean a mathematical thought. I assume you may want to explain that, because a kind of reality I can attribute to mathematical thoughts is squarely in your head, which is itself physical! (regardless of whether these ideas fit empirical reality, e.g. real reality) These thoughts are contained in your brain, sometimes as good descriptions of physical reality (e.g. physical properties can obviously be mathematical!) And sometimes their representations are to be found on extraneural marks, like Can there be mathematical objects that are not thoughts? Perhaps. I dont know. It could be said that the integers necessarily exist in any good representation of computations out there. We have an interesting picture, then. Every version of mathematical object has a physical existence. Not surprising if the world is only physical! So, reality of mathematical statements seems quite like the reality of physical statements! They are theoretical. They are first and foremost thoughts (to us!). They can be derived from thought experiments or empirical observations. This might be an easier route for you to answer. In exactly which fashion can we distinguish physical statements from mathematical statements? The only answer I can find is that (in current mathematics) * They dont have to directly correspond to physical systems, they can talk about certain mental constructions with desirable properties such as abstractness which are not *directly* derived from sensory experience or empirical trials e.g. graph theory. A graph is an abstract concept. But it is wrong to say that graphs do not exist in the real world. They certainly do, especially when programmed on a computer! But unfortunately there can be cases in mathematics that are not even *indirectly* derived from observations, that are solely the result of thought experiments and are indeed incompatible even with the basic features of our universe. I dont find this a desirable thing, because I find these to be misleading thought experiments. I suggest we put them aside until we can find a use for them. >In my opinion, most mathematicians think that real numbers existed >before humanity. > Of course they existed. But thats in the mathematical sense of > exist. In the ordinary meaning of exist, real numbers do not > exist even today. This mathematical sense of existence you are portraying gets even stranger. I assume you would want to state where I can find this intriguing position. What is it called? If its so common, it ought to have a name. By now, it appears that it is not intuitionism, which is something I might want to favor. Is it mathematical realism? And what kind of a mathematical realism? Or is it an unnamed fuzzy philosophical position like Torkels? (He avoided giving a name, because he probably has no clue what his position could be called) Its gotten quite mysterious. Im anxious to know its name! > That is seen by their naive reliance on the strict >truth of their assumptions about real numbers, and by the fact that >they think it is clear what is real! > It is clear that you are quite ignorant about mathematics, and > apparently proud of your ignorance. Educate this ignorant person, then, Neil. What is this unique philosophical position of yours called? (If its determinate, that is) Platonism? But if that is so, I already knew well about it, which is why I have taken the chance to show its absurdity. So, then either of the following is true 1) You are talking about a position other than Platonism, and Im sincerely wondering what this position is. Because despite some self-study, I cannot predict the name from your post exactly. 2) You dont know what Platonism is. By the way, another view that I might regard good enough would be some kind of mathematical instrumentalism, that might say that exist is used only as a figure of speech in mathematics, which is precisely what Im suggesting is the current practice. IOW, this exist has *nothing* to do with exist in the ordinary sense... Which is perhaps what you want to say... Are you an instrumentalist of some sort? But we should beware, when we say that, we are really coming to mathematical solipsism that I talked of a while ago! That does not seem desirable either! -- Eray Ozkural === Subject: Re: Platonism -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 >In short, does your position in philosophy of mathematics have a name? None that I am aware of. >I found it quite interesting! I wasnt expounding my philosophy. >> It is a mistake to assume that exist as used by mathematicians has >> the same meaning as it has when we talk of the existence of ordinary >> things. Likewise, mathematical usage of model is different from >> ordinary usage. >I actually like your point about model. But I cannot say if I like >the point about exist. What is this sense used by *most* >mathematicians then? Would you care to explain? [I dont say all, I >say most in the above discussion.] Often, mathematicians demonstrate existence by construction. Of course, that is the mathematical sense of construction. For the ordinary sense of exists, I will note that something exists after it has been constructed, and only until it has been destroyed. But when mathematicians construct an object, they conclude that it exists for all time. In particular, it existed before this particular construction, and it cannot be destroyed. This should illustrate why the mathematical sense of existence is different from the ordinary sense. >I am hoping you do not mean that in (most!) mathematics consistency is >identical to existence. That would be quite silly, would not it? Normally one applies the term consistency to systems of axioms, and existence to mathematical objects. An inconsistent system of axioms could still exist, even though inconsistent. >I think when I say a mathematical object, I usually mean a >mathematical thought. That does not work. For that would make mathematical objects subjective, and would imply that two different mathematicians have two distinct numbers three. It is important to mathematicians, that mathematical objects are objective. >The only answer I can find is that (in current mathematics) >* They dont have to directly correspond to physical systems, they can >talk about certain mental constructions with desirable properties such >as abstractness which are not *directly* derived from sensory >experience or empirical trials e.g. graph theory. A graph is an >abstract concept. But it is wrong to say that graphs do not exist in >the real world. They certainly do, especially when programmed on a >computer! The graphs that exist in the real world are not the graphs that mathematicians concern themselves with. >But unfortunately there can be cases in mathematics that are not even >*indirectly* derived from observations, that are solely the result of >thought experiments and are indeed incompatible even with the basic >features of our universe. I dont find this a desirable thing, because >I find these to be misleading thought experiments. I suggest we put >them aside until we can find a use for them. You only illustrate the extent to which you are confused about mathematics. >By the way, another view that I might regard good enough would be some >kind of mathematical instrumentalism, that might say that exist is >used only as a figure of speech in mathematics, which is precisely >what Im suggesting is the current practice. Thats approximately my own view. But most mathematicians disagree. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.3.91 (SunOS) iD8DBQFBp6xfvmGe70vHPUMRAq3AAJ0XUJpfIL8DYxxKo4U7V8V0N88xxACgm5 uh MQ0wGyeErv48+WWEdx7WhdU= =iaW7 -----END PGP SIGNATURE----- === Subject: Re: Platonism the point about exist. What is this sense used by *most* >mathematicians then? Would you care to explain? [I dont say all, I >say most in the above discussion.] >I am hoping you do not mean that in (most!) mathematics consistency is >identical to existence. That would be quite silly, would not it? >Eray Ozkural This is why you have missed so much of what has been said and why you say very naive things about behaviourism. Its also why I have frequently told you that you literally dont know what you are talking about. To be is to be the value of a variable - where is that from? What does it have to do with the failure of (existential) quantification into intensional contexts such as those of propositional attitude and the modalities)? What does that have to do with the extensional stance? -- David Longley http://www.longley.demon.co.uk/Frag.htm === Subject: Re: Platonism > That is in fact what we should do, and I think its been done fairly > well for integers, Apparently not, since you felt prompted to ask whether there are integers with an infinite number of digits. === Subject: Re: Platonism > That is in fact what we should do, and I think its been done fairly > well for integers, > Apparently not, since you felt prompted to ask whether there are > integers with an infinite number of digits. That was a pedagogical question (e.g. how do you tell what Z is to somebody whos never studied formal set theory, who is *not* me if you will try another sore joke), and it was a real explanatory issue that I faced trouble with over a coffee table. It has no bearing on the ontological status of Z. Z does not literally exist, but its a good model of certain computational properties of things in the world, so it can be said to exist, in the second order of existence (the conceptual existence) sense that Godel talks about, but unlike Godel we should not overlook the distinction between 1 and a chair. The nice thing about integers is that they are multiply realized, and we should really look at them as abstract properties of physical objects, in my opinion. Anyway, a complete description of their ontological status would take a couple of pages. Try to infer the rest from this paragraph. (You will object, anyway. I think you are a platonist. It is not a position to be proud of.) -- Eray Ozkural === Subject: Re: Platonism > (You > will object, anyway. I think you are a platonist. It is not a position > to be proud of.) Ive heard that in prison pecking order, it lies somewhere between car theft and property damage. -- Mitch Harris (remove q to reply) === Subject: Re: Platonism > That was a pedagogical question (e.g. how do you tell what Z is to > somebody whos never studied formal set theory, who is *not* me if you > will try another sore joke), and it was a real explanatory issue that > I faced trouble with over a coffee table. Right. You were wondering if there are integers with an infinite number of digits. === Subject: Re: Platonism >> That was a pedagogical question (e.g. how do you tell what Z is to >> somebody whos never studied formal set theory, who is *not* me if you >> will try another sore joke), and it was a real explanatory issue that >> I faced trouble with over a coffee table. > Right. You were wondering if there are integers with an infinite >number of digits. Im beginning to wonder if there are digits with an infinite number of digits. === Subject: Re: Platonism >> That was a pedagogical question (e.g. how do you tell what Z is to >> somebody whos never studied formal set theory, who is *not* me if you >> will try another sore joke), and it was a real explanatory issue that >> I faced trouble with over a coffee table. > Right. You were wondering if there are integers with an infinite >number of digits. > Im beginning to wonder if there are digits with an infinite number of > digits. So, can you imagine that? Why, then, that too should be included in some strange, nonsense theory, according to mathematical Platonism, which does not seem to be concerned with the sensibility or usefulness of mathematical theories. I penned such absurd theories, to show just how absurd and unreal real numbers are, and I think they turn out to be much less real than what Chaitin or Kronecker may have thought. There is a set that I call Absurd numbers, it will be quite fun when I write about it. With a little effort, you can construct all kinds of mathematical absurdities that are consistent in their own right. -- Eray Ozkural === Subject: Re: Platonism Originator: harris@tcs.inf.tu-dresden.de (Mitchell Harris) >> Im beginning to wonder if there are digits with an infinite number of >> digits. >So, can you imagine that? Why, then, that too should be included in >some strange, nonsense theory, according to mathematical Platonism, >which does not seem to be concerned with the sensibility or usefulness >of mathematical theories. >I penned such absurd theories, to show just how absurd and unreal real >numbers are, and I think they turn out to be much less real than what >Chaitin or Kronecker may have thought. There is a set that I call >Absurd numbers, it will be quite fun when I write about it. With a >little effort, you can construct all kinds of mathematical absurdities >that are consistent in their own right. This would make more sense to me if you replaced platonism with formalism, where formalism is (very loosely) about playing games with symbols irrespective of their meaning. Mitch === Subject: Re: Platonism ... >>I penned such absurd theories, to show just how absurd and unreal real >>numbers are, and I think they turn out to be much less real than what >>Chaitin or Kronecker may have thought. There is a set that I call >>Absurd numbers, it will be quite fun when I write about it. With a >>little effort, you can construct all kinds of mathematical absurdities >>that are consistent in their own right. >This would make more sense to me if you replaced platonism with >formalism, where formalism is (very loosely) about playing games with >symbols irrespective of their meaning. I thought playing games with symbols irrespective of their meaning was (very loosely) Usenet. Lee Rudolph === Subject: Re: Platonism > Im beginning to wonder if there are digits with an infinite number of > digits. That makes no sense. Every integer is finite so every integer is representable by a finite sum of powers of a base > 1. Bob Kolker === Subject: Re: Platonism >> Im beginning to wonder if there are digits with an infinite number of >> digits. >That makes no sense. Every integer is finite so every integer is >representable by a finite sum of powers of a base > 1. Im not sure the thread makes any sense. Surely there are more topical topics in fundamental mathematics than the cryptoplatonism of mathematicians. Please excuse my boorish observation. === Subject: Ozkural was Re: Platonism >> That was a pedagogical question (e.g. how do you tell what Z is to >> somebody whos never studied formal set theory, who is *not* me if you >> will try another sore joke), and it was a real explanatory issue that >> I faced trouble with over a coffee table. > Right. You were wondering if there are integers with an infinite > number of digits. Indeed. His question was not How do I explain to my interlocutors that each integer has finitely many digits in its base ten representation? it was are there integers with an infinite number of digits?. -- Robin Chapman, www.maths.ex.ac.uk/~rjc/rjc.html Lacan, Jacques, 79, 91-92; mistakes his penis for a square root, 88-9 Francis Wheen, _How Mumbo-Jumbo Conquered the World_ === Subject: Re: Ozkural was Re: Platonism > >> That was a pedagogical question (e.g. how do you tell what Z is to >> somebody whos never studied formal set theory, who is *not* me if you >> will try another sore joke), and it was a real explanatory issue that >> I faced trouble with over a coffee table. Right. You were wondering if there are integers with an infinite > number of digits. > Indeed. His question was not > How do I explain to my interlocutors that each integer has finitely > many digits in its base ten representation? > it was > are there integers with an infinite number of digits?. Doh! Not interlocutors, friends. I asked it like that, and why did I do that? Because my friends asked me that question. And I had no good answer. They asked me Why not?, and I could not answer except by saying that is how we define things. doesnt it make sense?... So I forwarded the question here, and I quoted the philosophical context later on. I thought that was the proper way to do it. Anyway, you two never understood the gist of that discussion, or made any useful comment. You did not understand my friends well motivated attack against the definitional issues in Cantors theorem, either. But you are both doing extremely well in your ad hominem arguments, and misrepresenting my ideas. I did try to develop upon my friends ideas, and I think I had some nice arguments philosophically (but quite useless mathematically!). The question does not belong to me originally. It is someone elses who doesnt post here, but I agree with the idea behind the question although the answer is obviously NO given the elementary definitions they teach us in secondary school in Turkey. (So, I was surprised that you guys could think it was possible for a grad. student to miss such easy stuff. That may be the case for US or Britain, but its never the case in Turkey.) I concluded that the answer might be definitional from a more generalist point of view. So, yes, I came close to being a formalist of some sort it seems. Im very interested in the shape of things. I dont think they necessarily refer to things out there, which would be Platonism. Maybe it refers only to things in here. But you two naively think that integers are like that, because they refer to some truth or reality or whatever out there. You think it is not because that is how we define integers, which is precisely the case! How can you know that whatever truth is out there, even if the outdated doctrine of Platonism holds in our world, corresponds to whatever is in your tiny heads? You cannot. Keep searching. The truth is not quite out there. Its in your head, too. -- Eray === Subject: Re: Ozkural was Re: Platonism > I asked it like that, and why did I do that? Because my friends asked > me that question. And I had no good answer. Right. You were wondering, Are there integers with an infinite number of digits? === Subject: Re: Platonism >I thought most >mathematicians who expressed an opinion were generally some sort of >Platonists, believing that effective mathematics is discovered, not >invented, and that it is the real world which approximates the ideal. > ... >> Mostly, people do not endorse mathematical platonism which means >> mathematics pre-exists and is discovered in another realm by the >> mathematician. > I disagree ... sort of. People is a bit too broad. I was under the > impression that mathematicians are naively platonistic, in that, without > giving too much thought to it, they consider all the things they work with > as real as anything a mechanical engineer works with. and dont ponder too much about the unreasonable effectiveness of mathematics. I knew that mathematicians were cultish about it and I couldnt make the assertion that I did about their narrower group so I used a larger group where my statement is true. Using mathematician in the definition of mathematical platonism was a necessary evil. I couldnt legitimately say, Mostly, mathematicians do not endorse mathematical platonism because they do. So I used the larger class of people who for varied reasons do not endorse mathematical platonism. (Never heard of it; huh, that sounds like a fairy tale; I dont have time for that kind of nonsense because I shut up and calculate.) > But for those mathematicians who care about philosophy, they are split > between those who think that platonism is totally discredited, and those > who accept a weak form of it (realism or naturalism). So I mostly agree with what you say about mathematicains, but that is not typical for people like research historians, computer technicians, bookies, perhaps some linguists, and the majority of philosophers. Were you by any chance thinking of a mathematician as a person? > -- > Mitch Harris > (remove q to reply) === Subject: Re: Platonism >>I thought most >>mathematicians who expressed an opinion were generally some sort of >>Platonists, believing that effective mathematics is discovered, not >>invented, and that it is the real world which approximates the ideal. >>... >Mostly, people do not endorse mathematical platonism which means >mathematics pre-exists and is discovered in another realm by the >mathematician. >>I disagree ... sort of. People is a bit too broad. I was under the >>impression that mathematicians are naively platonistic, in that, without >>giving too much thought to it, they consider all the things they work with >>as real as anything a mechanical engineer works with. > and dont ponder too much about the unreasonable effectiveness of > mathematics. > I knew that mathematicians were cultish about it and I couldnt > make the assertion that I did about their narrower group so I > used a larger group where my statement is true. Using mathematician > in the definition of mathematical platonism was a necessary evil. > I couldnt legitimately say, Mostly, mathematicians do not endorse > mathematical platonism because they do. So I used the larger > class of people who for varied reasons do not endorse mathematical > platonism. (Never heard of it; huh, that sounds like a fairy tale; I dont > have time for that kind of nonsense because I shut up and calculate.) OK. I would say (in my own overgeneralized wording) that those who are non mathematically oriented (mathematically/philosophically naive?)) would deny existence of -any- mathematical concept beyond those having immediate physical tangibles like specific numbers or distance. (taking the oversimplification of platonism as the philosophy that mathematical things exist.) >>But for those mathematicians who care about philosophy, they are split >>between those who think that platonism is totally discredited, and those >>who accept a weak form of it (realism or naturalism). > So I mostly agree with what you say about mathematicains, but that is > not typical for people like research historians, computer technicians, > bookies, perhaps some linguists, and the majority of philosophers. > Were you by any chance thinking of a mathematician as a person? For actuarial purposes, I suppose one would be forced to. ;) I think that was my quibble with your use of Mostly, people. I was trying to leave out the non-mathematician. -- Mitch Harris (remove q to reply) === Subject: Re: Platonism > For actuarial purposes, I suppose one would be forced to. ;) > I think that was my quibble with your use of Mostly, people. I was > trying to leave out the non-mathematician. > -- Well, in my view mathematical platonism is a philosophical assumption rather than an experienced reality. So the mathematician is closer to the experienced reality but I dont see that as a qualification, since Im not a platonist, which makes a consistent viewpoint. Their opinion of their experienced reality has no causal effect on creating a platonic realm. A shared delusion rather than a special insight. So then speaking of mathematicians, I see no special philosophical insight demonstrated by mathematicians in general or the talent for doing math. I sit here and think of good physicists who were also good mathematicians and philosophers, and there are a few. David Bohm comes to mind at the top of my list. But pure mathematicains... That is my reason for leaving out the mathematican. When I write I discover potentials in the writing which I didnt plan or invent, so that is a type of discovery. And some artists describe sculpting for instance as chipping away the exterior to reveal the hidden content. But I dont see that as justifying a platonic realm, rather a cultist belief, in the strong version of platonism. Stephen === Subject: Re: Turing Machines and Physical Computation >You are missing the entire point that computation is meant to be a >physical process. That is all there is to computation. It is a theory >of computing machines. And it describes a large number of them. Lets >get down to your particular objections to my detailed analysis. >But every couple of months, a naive mathematician will show up (not >you) and try to purport an imaginery dichotomy between physical >computation and Turing computation. That is unfortunate, very >unfortunate indeed, because in my opinion it shows a systematic mental >error. > Although a theory of physical computing machines is possible, we do not > have such a theory as yet. > The Turing Machine, as A. M. Turing specified it, cannot calculate pi, > but it can calculate any finite number of digits of pi, such as > (10^(10^(10^(10^(10^1000))))) digits of pi, even though no > physically-realizable computer could calculate that many digits of pi. > Turing _did_ specify the Turing machine that way, so it is a fact that > he made the same systematic mental error you refer to. Why did he do > such a thing? > Because it made it possible for him to derive results from his theory in > a reasonable amount of time. Determining what the limits of computation > in the physical universe are, and what can be done within those limits, > is a very complicated problem. Assuming infinite memory capacity is a > simplifying assumption that makes for a theory much easier to derive and > work with There is nothing wrong in Turings theory, and Pi is a computable real, which means that not that the actual real number can be ever generated, but only that arbitrarily many digits of it can be generated in finite time. > What is the use of such a theory, a theory that doesnt refer to the > real world? You would be wrong to think it does not refer to the real world. The interesting portion of the theory makes predictions squarely in the real world, thats why the theory is relevant in everyday computing. > If certain things cannot be done with even an infinite > memory, then they cannot be done with a finite memory. There is no such thing as infinite memory, the tape is unbounded, not infinite. We need to make the distinction. When you above said capacity, it was potential and therefore admissible exactly in the same fashion as that every integer, by definition, is finite. (Integers are *integral*) > And many things > that can be computed dont need an infinite amount of memory, or even an > absurdly large finite one. So the Turing machine is an *approximation* > to a real computing machine. Its more than an approximation. Physical computation does not mean that we need to specify the quantum state transitions, or give physical bounds or formulate a GUT or anything like that. The Turing Machine gives an exact characterization of the causal structure of computing machines, and that is very physical. The Turing Machine is a blueprint. You can take it, and build a variety of machines using it, but no information WITH RESPECT TO COMPUTATION is missing in the blueprint, which means the blueprint is exact with respect to computation. (In that it describes exactly HOW to perform the computation, which is the necessary question to answer to be able to compute at all) There is a difference between a theory which is inexact in all facts, and a theory that is exact in many facts, and makes conditional predictions in general that would hold in nomologically similar (possible) worlds. In the general sense, the Turing Machine is a metaphysical model of causal systems. Is that significant? Yes. But that is so because it depicts a set of close-by possible worlds, including our own world, in which this causal model corresponds to general mechanical laws. Whether our world is infinite or finite (which is a matter to be eventually settled by astrophysics observations), is irrelevant for the theory, because its a general theory. However, it depicts no worlds that are physically remote from our own. Thats why it carries a notion of weak physicalism. (There are discussions more to the point, but it would be useless to discuss these with Harris, who does not seem capable of discussing these within a coherent metaphysics as I maintain) > lines made with real pencils and the pinpricks made by the point of a > real compass, mathematicians have always approximated the real world by > abstractions which are not physically realizable. This makes the > symbolic manipulations in mathematics simpler - and thus makes them > realizable instead of impractical. Giving this up would mean giving up > mathematics, because taking into account the limitations of the real > world in every case would make many fields far too complicated to > investigate. Not bad points, Jon. We abstract at the cost of losing reality. The more we lose reality, the less real our theories become. I suggest that the reality of Turing computation is not severely diminished by the fact that it addresses a set of physically similar worlds. For the model captures the essence of causality, and that is sufficient for it to explain computation. This is a philosophical argument. I would welcome further discussion on individual points, I hope these points sound interesting to you. A tiny argument may be missing in the above exposition. It is a theory that deals with possible worlds, and its statements can be seen as conditional (If the world has finite space, then we can construct *these* machines). However, the approach is constructive, we take the coarse-grained causal laws of our universe, and generalize them, without positing anything that we are not sure of. Therefore, its a scientific way of making metaphysics. Its a very very new thing (thats why some people still have trouble understanding it), and its much more powerful than the logical positivist account. Positivism = Physicalism + Constructivism + Nominalism gives us a solution. Its a new foundation not only for mathematics, but also for computation, which may be more general than mere mathematics (which seems to have specific concerns!). I cannot tell anything about whether the approach of Turing has a solipsist favor. I think it does not, but at one level it might give rise to a solipsist level (some mental states might be exactly that). The level we are interested in at the moment seems quite real! But when we talk about these large cardinal axioms, oh, we are being solipsists. -- Eray Ozkural PS: So, I think I largely agree with Joshua Stern. === Subject: Re: Turing Machines and Physical Computation >>You are missing the entire point that computation is meant to be a >>physical process. That is all there is to computation. It is a theory >>of computing machines. And it describes a large number of them. Lets >>get down to your particular objections to my detailed analysis. SH: Eray, his is another one of your premises that conßicts with the facts. Turing was mathematician interested in the foundations of mathematics. Hilbert made up a list of 23 questions to put mathematics on firm footing. Im pretty sure that it is number 10 on this list that Turing referred to in his famous 1936 paper, On computable numbers, with an application to the Entscheidungsproblem The paper had two purposes to define the nature of an algorithm and to give a better negative answer to Hilberts challenge: A decision problem was a general question: Given any sequence of symbols, is it a formula? or Given any formula, is it provable? A solution to a decision problem was an effective procedure, a uniform method or algorithm, specified by a finite set of rules, by which each instance of the general question could be answered in a finite number of steps. An effective procedure could not appeal to intuition, understanding, creativity, or guesswork, and always generated the correct answer. http://www.artsci.wustl.edu/~gpiccini/Alan%20Turing%20and% 20the%20Mathematic al%20Objection.pdf L. E. J. Brouwer was the main supporter of intuitionism, according to which an existence proof for a _mathematical object_ was admissible only if it exhibited a construction of the object (Brouwer 1974). Brouwer was also against Cantorian set theory which also made use of the diagonalization process. Turing was improving Godels result which answered Hilbert question 10 negatively. Turing was attempting to show his answer as a constructive process for exhibiting proof of a ***mathematical object***, not the physical object you claim. >>You are missing the entire point that computation is meant to be a >>physical process. That is all there is to computation. Maybe they had an old fashioned hand-driven adding machine that you see in old movies. Computation was done by office clerks. Turing claimed that his Turing machine could perform mechanical procedures like these clerks; that it was mechanical in the sense of by rote, no ingenuity was involved, no creativity. That was the computation performed by human computer and claimed for turing machines. computers existing in order to point the purpose of direction you claim, realization of a physical computing machine. I think he was exposed to a primitive analog computer in 1937. After he worked on encryption during WWII I think he got the notion of a physical device. Then someone realized that tubes could be used to compute with and I think the first proto-digital computer was around 1946. I think it was 1948 when Turing introduced thinking machines---much after his Turing machine paper. You just seem to be ignoring the fact that the theory that present day computers borrow heavily from started as a theory. It was a mathematical-logical theory not at all intended to provide a blueprint for physical digital computers. That happened afterward, a development. That is why I can find so many quotes on the web describing a turing machine as an abstract hypothetical device. That is its historical origin. http://www.unidex.com/turing/tm_intro.htm A Turing machine can be thought of as a primitive, abstract computer. Alan Turing, who was a British mathematician and cryptographer, invented the Turing machine as a tool for studying the computability of mathematical functions. Turings hypothesis (also known has Churchs thesis) is a widely held belief that a function is computable if and only if it can be computed by a Turing machine. This implies that Turing machines can solve any problem that a modern computer program can solve. There are problems that can not be solved by a Turing machine (e.g., the halting problem); thus, these problems can not be solved by a modern computer program. Im not arguing with this. I factually stated some problems are tractable for TMs that are not tractable for PCs because of time. The heat death of the universe comes about because of the passage of time which means there is no more energy available in order to power physical computing. This is somewhat like the idea that quantum computers are supposed to solve some computable problems that are intractable for conventional PCs. I say somewhat because this introduces time, which is not a TM factor. How many intractable problems are there? Infinite. >>But every couple of months, a naive mathematician will show up (not >>you) and try to purport an imaginery dichotomy between physical >>computation and Turing computation. That is unfortunate, very >>unfortunate indeed, because in my opinion it shows a systematic mental >>error. You are committing a systematic mental error. The one you refer to is when people mistakenly claim that TMs cannot compute what a digital computer (pc) can compute. This is true without claiming inherent randomness in the physical computer. I have stated the converse of this statement. That some problems are intractable for PCs because of the time element; but those problems are not intractable for TMs because Turing invented TMs without any reference to time and he gave the TM an infinite tape so there is no shortage of memory problem (the tape doesnt halt unexpectedly because it runs out like an adding machine) which eliminates physical constraints from TMs that do impact PCs. I made no assertion that the topic of physical computation was historically less important now. The physical aspect was certainly less developed, if at all, when the mathematical theory of a TM was created. TMs are not physical. > Although a theory of physical computing machines is possible, we do not > have such a theory as yet. > The Turing Machine, as A. M. Turing specified it, cannot calculate pi, > but it can calculate any finite number of digits of pi, such as > (10^(10^(10^(10^(10^1000))))) digits of pi, even though no > physically-realizable computer could calculate that many digits of pi. > Turing _did_ specify the Turing machine that way, so it is a fact that > he made the same systematic mental error you refer to. Why did he do > such a thing? > Because it made it possible for him to derive results from his theory in > a reasonable amount of time. Determining what the limits of computation > in the physical universe are, and what can be done within those limits, > is a very complicated problem. Assuming infinite memory capacity is a > simplifying assumption that makes for a theory much easier to derive and > work with. > What is the use of such a theory, a theory that doesnt refer to the > real world? If certain things cannot be done with even an infinite > memory, then they cannot be done with a finite memory. And many things > that can be computed dont need an infinite amount of memory, or even an > absurdly large finite one. So the Turing machine is an *approximation* > to a real computing machine. > lines made with real pencils and the pinpricks made by the point of a > real compass, mathematicians have always approximated the real world by > abstractions which are not physically realizable. This makes the > symbolic manipulations in mathematics simpler - and thus makes them > realizable instead of impractical. Giving this up would mean giving up > mathematics, because taking into account the limitations of the real > world in every case would make many fields far too complicated to > investigate. > John Savard > http://home.ecn.ab.ca/~jsavard/index.html I think the literature supports your statements: http://plato.stanford.edu/entries/turing-machine/ In modern terms, the tape serves as the memory of the machine, while the read-write head is the memory bus through which data is accessed (and updated) by the machine. There are two important things to notice about the definition. The first is that the machines tape is infinite in length, corresponding to an assumption that the memory of the machine is infinite. The second is similar in nature, but not explicit in the definition of the machine, namely that a function will be Turing-computable if there exists a set of instructions that will result in the machine computing the function regardless of the amount of time it takes. One can think of this as assuming the availability of infinite time to complete the computation. [SH: I prefer to think of it as having no time involved, rather than infinite.] These two assumptions are intended to ensure that the definition of computation that results is not too narrow. This is, it ensures that no computable function will fail to be Turing-computable solely because there is insufficient time or memory to complete the computation. If a function is not Turing-computable it is because Turing machines lack the computational machinery to carry it out, not because of a lack of spatio-temporal resources. ------------------------------------------------------------- ------- These are called abacus computers by Lambek (Lambek 1961), and are known to be equivalent to Turing machines. The modern digital computer is subject to finiteness constraints that we have abstracted away in the definition of abacus machines, just as we did in the case of Turing machines. Physical computers are limited in the number of memory locations that they have, and in the storage capacity of each of those locations, while abacus machines are not subject to those constraints. Thus some abacus-computable functions will not be computable by any physical machine. (We wont consider whether Turing machines and modern digital computers remain equivalent when both are given external inputs, since that would require us to change the definition of a Turing machine.) ------------------------------------------------------------- --------------- - http://www.alanturing.net/turing_archive/pages/Reference% 20Articles/What%20i s%20a%20Turing%20Machine.html#head Commercially available computers are hard-wired to perform primitive operations considerably more sophisticated than those of a Turing machine --add, multiply, decrement, store-at-address, branch, and so forth. The precise constitution of the list of primitives varies from manufacturer to manufacturer. It is a remarkable fact that none of these computers can outdo a Turing machine. Despite the Turing machines austere simplicity, it is capable of computing anything that any computer on the market can compute. Indeed, since it is an abstract or notional machine, a Turing machine can compute more than any physical computer. This is because (1) the physical computer has access to only a bounded amount of memory, and (2) the physical computers speed of operation is limited by various real-world constraints. It is sometimes said, incorrectly, that a Turing machine is necessarily slow, since the head is continually shufßing backwards and forwards, one square at a time, along a tape of unbounded length. But since a Turing machine is an idealised device, it has no real-world constraints on its speed of operation. Stephen === Subject: Re: Turing Machines and Physical Computation <419c4735$0$44080$5fc3050@dreader2.news.tiscali.nl> <419cd7d4$0$44068$5fc3050@dreader2.news.tiscali.nl> <4zrnd.46389$QJ3.16198@newssvr21.news.prodigy.com> are practical is useful at all. The issue being discussed is not >practical/physical >but theoretical, hypothetical and abstract; an idea not a physical thing. Are you sure about that? Are you sure you havent missed the whole point of what the first half of 20th century philosophy and earlier (from Frege to Goedel and beyond) was really all about? It was, I suggest, a record of failure - the failure of analyticity and the banality of computing. The collapse of any search for foundations for philosophy (of mathematics) led to an enlightened empiricism (which abandons intensionalism or analyticity, along with reductionism in favour of extensionalism. Naturalisation of epistemology is behavioural science, and that comes down to the experimental and applied analysis of behaviour. That sadly often comes down to money management and politics as far as applied behaviour analysis is concerned. Ideas are intensions. Ive suggested before that you should read some Skinner and Quine. Skinners 1945 paper might help some to appreciate how and why Wittgensteins later philosophy is really a therapy for folk like you who still havent learned the lessons of the first part of the 20th century. It makes all this talk of AI nonsense as you dont appreciate the limits of analyticity - without data its solipsistic or blind (as Kant would say). You are just rehashing old words in new ways. Wittgenstein (or Skinner) would also have shown you (if any of you would have listened) that youre largely just talking bosh. I bet you wouldnt have liked Wittgenstein either as youd have had to want to court criticism to benefit, ie youd have to have been able to recognize that you need therapy. Note that Ozkural doesnt even like Quine ;-). Do you see a pattern emerging here? He doesnt like Sizemore either. No doubt were all rude, mentally ill or senile (if not dead). No doubt were all in your killfiles ;-). Folk in these newsgroups need to understand that psychiatric terms are not terms of abuse (and that all considered, the behaviours they refer to are far more common than most folk appreciate (cf. Post and Goedel, Turing and many others (the link is in here k>). These terms classify variants of normal human diversity, emitted at higher frequencies than normal. The word idiot on the other hand seems to come close to being a synonym or discriminative stimulus for a measure of central tendency, so perhaps some of you guys should, given your penchant to use psychiatric classifications as terms of abuse, be proud to be thought of as idiots? ÔI have had neither the aptitude nor the temperament for debate, public or private, when confronted with motives recognizably other than the pursuit of truth. If in discussing with a student I sensed that he was animated rather by some ideological preconception, or by a wish to have been right for the sake of high marks or self- esteem, I make short work of the dialogue. A vast gulf, insufficiently remarked, separates those who are primarily concerned to have been right from those who are primarily concerned to be right. The latter, I like to think, will inherit the earth. - W.V. Quine The Time of My Life (1985). ÔRhetoric is the literary technology of persuasion, for good or ill. It is the rallying point for advertisers, trial lawyers, politicians, and debating teams. - Debating teams are promoted in schools as a spur to effective language and incisive thought. They serve that purpose, but only by setting the goal of persuasion above the goal of truth. The debaters strength lies not in intellectual curiosity nor in amenability to rational persuasion by others, but in his skill in defending a preconception come what may. His is a nefarious knack of disregarding all the discrepancies while regarding every crepancy. - The same skill, along with legal lore, is the strength of the trial lawyer or barrister, and the strength also of the successful politician, one or the other of which careers the captain of the the debating team is clearly destined for. Happily there are lawyers who will only take on such cases as they deem to be just, and politicians who will espouse only a case which is righteous; but these scruples are not adjuncts of the rhetorical pole, nor are they keys to success in the legal or political profession. - When an electorate or a jury is the sway of a demagogues rhetoric, cold reason and the marshaling of facts bear little promise in rebuttal. Marshaling more rhetoric, then, in a contrary vein, we fight fire with fire. Rhetoric is invaluable homeopathically in withstanding its own assaults. - In scientific circles there is little demagogy to combat, but rhetoric is sometimes of service even there; for in an extremity it may happen that a scientist needs more than a cold statement of his theory and his evidence if he is ever to shake the stubborn and mistaken preconceptions of some of his students, let alone his dissident colleagues. But rhetoric in the wrong scientists hands can do disservice to science. It can help him put his theory across for his reputations sake despite some shakiness in the evidence. - Rhetoric, then, is sometimes nefarious and sometimes not. In its nefarious use it is the art or practice of defending a proposition on grounds other than ones own reasons for defending it. An auxiliary device is innuendo. A Ôreferentially translucent expression, as Randal Marlin call it, is subtly ambiguous: it can be taken as objectively stating a result of an action, and it can be taken as accusing the agent of intending that result. One of Marlins examples is the headline ÔPope Fouls Up Bar Mitzvah. The Popes arrival in town caused a traffic jam that rendered the synagogue inaccessible for the Bar Mitzvah; but the headline can be taken as hinting unjustly of hostility on the Popes part towards Jews. It is an insidious device, effective in warping unsuspecting minds while still adhering, in a sense, to the verifiable. - Nefarious rhetoric is rife not only in tendentious journalism, television commercials, courts of law, Congress, political rallies, and the United Nations, but also in homelier settings. In a New England town meeting a citizen will describe in glowing terms the public advantages which accrue from some proposed measure, when what is at stake deep down has to do with his own interest as proprietor, abutter, investor or contractor. In such a case we do not cope with abuse by meeting rhetoric with rhetoric, fire with fire, we just expose the mans motives. What is important is to be alert to what is going on, and not accept insincere argument at face value. This much applies to the august and the humble ones alike. - What I have been calling nefarious rhetoric recurs in a rudimentary form also in impromptu discussions. Someone interest, and marshals ever more desperate and threadbare arguments in defence of his position rather than be swayed by reason or face the facts. Even more often, perhaps, the deterrent is just stubborn pride: reluctance to acknowledge error. Unscientific man is beset by a deplorable desire to have been right. The scientist is distinguished by a desire to BE right. - Rhetoric - QUINE (1987) Quiddities -- David Longley http://www.longley.demon.co.uk/Frag.htm === Subject: Re: Turing Machines and Physical Computation >I cant see how bringing finite TMs into this issue, just because they >are practical is useful at all. The issue being discussed is not >practical/physical >but theoretical, hypothetical and abstract; an idea not a physical thing. > Are you sure about that? Are you sure you havent missed the whole point > of what the first half of 20th century philosophy and earlier (from > Frege to Goedel and beyond) was really all about? In this part I might actually agree with Longley! Dolan and others miss the whole point! Analytical/synthetic distinction indeed does not exist. (And on that point I agree with Quine) Why is this distinction relevant? Because saying that an idea is not a physical thing is a lot like saying that well, ideas can be purely analytical. analytical concepts are DISTINCT from synthetic concepts, so it can be the case that an idea is not a physical thing.... Close enough. This is of course a very confused philosophy. Saying that an idea is not a physical thing is an automatic admission of Cartesian Dualism. It shows that the person who said it NEVER READ ANY 20th CENTURY PHILOSOPHY. And I suggest such ignorant persons like Dolan to stay away from philosophical discussions, it is not their league. > It was, I suggest, a > record of failure - the failure of analyticity and the banality of > computing. The collapse of any search for foundations for philosophy > (of mathematics) led to an enlightened empiricism (which abandons > intensionalism or analyticity, along with reductionism in favour of > extensionalism. Well, of course I dont agree with this. Computing is not banal. It is not analytic either. How did you make that up? And here is a serious question for you, David. If programming languages are extensional as you like to proclaim, how come computing not be an adequate tool for extensional stance? [snip more stuff I find irrelevant] -- Eray Ozkural === Subject: Re: Turing Machines and Physical Computation > In this part I might actually agree with Longley! Dolan and others > miss the whole point! Analytical/synthetic distinction indeed does not > exist. (And on that point I agree with Quine) Why is this distinction > relevant? Because saying that an idea is not a physical thing is a > lot like saying that well, ideas can be purely analytical. analytical > concepts are DISTINCT from synthetic concepts, so it can be the case > that an idea is not a physical thing.... Close enough. An idea is a recognition of a possibility (note it is physical in an appropriate ontology). Some ideas go on to become implemented (or stick) in our culture ... the WWW was Tim Berners-Lees idea at some point. Now what has recognition of a possibility got to do with the analytical/synthetic distinction again? Nothing, imho. patty === Subject: Re: Turing Machines and Physical Computation http://mygate.mailgate.org/mynews/comp/comp.theory/ 207fe873374c584e8a375f35c5 b1d9f7.48257%40mygate.mailgate.org >> I cant see how bringing finite TMs into this >> issue, just because they are practical is useful >> at all. The issue being discussed is not >> practical/physical but theoretical, hypothetical >> and abstract; an idea not a physical thing. > Are you sure about that? Are you sure you havent > missed the whole point of what the first half of > 20th century philosophy and earlier (from Frege to > Goedel and beyond) was really all about? David, since you have utterly no concept what the subject under discussion is (hint philosophy is the wrong answer), nor education nor inclination ever to understand the subject matter, how about learning to hold your peace, rather than riding your inane hobby horse to trample roughshod over yet another conversation to which you were not invited, in which you do not belong, and where all you can do is (correctly) portray yourself to be a classic boorish dolt? HTH xanthian. -- === Subject: Re: Turing Machines and Physical Computation <419c4735$0$44080$5fc3050@dreader2.news.tiscali.nl> <419cd7d4$0$44068$5fc3050@dreader2.news.tiscali.nl> <4zrnd.46389$QJ3.16198@newssvr21.news.prodigy.com> <207fe873374c584e8a375f35c5b1d9f7.48257@mygate.mailgate.org I cant see how bringing finite TMs into this > issue, just because they are practical is useful > at all. The issue being discussed is not > practical/physical but theoretical, hypothetical > and abstract; an idea not a physical thing. >> Are you sure about that? Are you sure you havent >> missed the whole point of what the first half of >> 20th century philosophy and earlier (from Frege to >> Goedel and beyond) was really all about? >David, since you have utterly no concept what the >subject under discussion is (hint philosophy is >the wrong answer), nor education nor inclination >ever to understand the subject matter, how about >learning to hold your peace, rather than riding your >inane hobby horse to trample roughshod over yet >another conversation to which you were not invited, >in which you do not belong, and where all you can do >is (correctly) portray yourself to be a classic >boorish dolt? >HTH >xanthian. If you want to restrict your metaphysics to sci.maths, comp.theory or misc.misc thats fine by me. But you should understand that computers per se had very little to do with Turing despite what you think. We had computers long before. What Turing and the others did was provide a theory of computing. The real histories in life are not all in the public domain. Its often deemed not to be in the public interest. -- David Longley === Subject: Re: Turing Machines and Physical Computation http://mygate.mailgate.org/mynews/comp/comp.theory/ 9397b9e1ec6b19e17df4e66701 f8971d.48257%40mygate.mailgate.org > If you want to restrict your metaphysics to > sci.maths, comp.theory or misc.misc thats fine by > me. Which part of you, David Longley butting into conversations where you have no credentials to participate, nor ability to talk about anything currently being discussed there, was so hard for you to grasp that the above non sequitur about _my_ choices was your reply? You are not merely mentally ill, David, but grievously dysfunctionally mentally ill, and with a severity more than a match for my own sorry situation. In my case my illness still leaves me a contributing member of signal on Usenet, mostly in comp.ai.genetic, in your case your illness limits you to being part of the noise factor only, everywhere I see you posting, everything I see you post. Based on the other responses you receive, this seems to be an all but universally held opinion of you. I can easily count your fellow travelers on the fingers of one hand, while your (correct) detractors number beyond my ability to tally at all. HTH xanthian. -- === Subject: Re: Turing Machines and Physical Computation <419c4735$0$44080$5fc3050@dreader2.news.tiscali.nl> <419cd7d4$0$44068$5fc3050@dreader2.news.tiscali.nl> <4zrnd.46389$QJ3.16198@newssvr21.news.prodigy.com> <207fe873374c584e8a375f35c5b1d9f7.48257@mygate.mailgate.org> <4mCho$BsJGoBFw7C@longley.demon.co.uk> <9397b9e1ec6b19e17df4e66701f8971d.48257@mygate.mailgate.org> If you want to restrict your metaphysics to >> sci.maths, comp.theory or misc.misc thats fine by >> me. >Which part of you, David Longley butting into >conversations where you have no credentials to >participate, nor ability to talk about anything >currently being discussed there, was so hard for >you to grasp that the above non sequitur about _my_ >choices was your reply? >You are not merely mentally ill, David, but >grievously dysfunctionally mentally ill, and with a >severity more than a match for my own sorry >situation. In my case my illness still leaves me a >contributing member of signal on Usenet, mostly in >comp.ai.genetic, in your case your illness limits >you to being part of the noise factor only, >everywhere I see you posting, everything I see you >post. >Based on the other responses you receive, this seems >to be an all but universally held opinion of you. I >can easily count your fellow travelers on the >fingers of one hand, while your (correct) detractors >number beyond my ability to tally at all. >HTH >xanthian. Ah, but note that youre nose-counting like many others, and thats not a reliable way to pursue truth. Theres nothing particularly pathological in what Im doing here, nor is there what Ive been doing elsewhere. That you think otherwise is largely a function of your not having followed up what I have provided, or acting on other advice that I (and others) have given you in the past. In other words, you wilful ignorance accounts for your poor grasp of what I have been doing/saying. Im explicating something about normal behaviour, not just delinquent or pathological behaviour. You should look into the differences between rule governed behaviour, and behaviour controlled by other contingencies - and then think about this thread title. -- David Longley === Subject: Re: Turing Machines and Physical Computation > If you want to restrict your metaphysics to > sci.maths, comp.theory or misc.misc thats fine by > me. >>Which part of you, David Longley butting into >>conversations where you have no credentials to >>participate, nor ability to talk about anything >>currently being discussed there, was so hard for >>you to grasp that the above non sequitur about _my_ >>choices was your reply? >>You are not merely mentally ill, David, but >>grievously dysfunctionally mentally ill, and with a >>severity more than a match for my own sorry >>situation. In my case my illness still leaves me a >>contributing member of signal on Usenet, mostly in >>comp.ai.genetic, in your case your illness limits >>you to being part of the noise factor only, >>everywhere I see you posting, everything I see you >>post. >>Based on the other responses you receive, this seems >>to be an all but universally held opinion of you. I >>can easily count your fellow travelers on the >>fingers of one hand, while your (correct) detractors >>number beyond my ability to tally at all. >>HTH >>xanthian. > Ah, but note that youre nose-counting like many others, and thats not > a reliable way to pursue truth. Theres nothing particularly pathological > in what Im doing here, nor is there what Ive been doing elsewhere. That > you think otherwise is largely a function of your not having followed up > what I have provided, or acting on other advice that I (and others) have > given you in the past. In other words, you wilful ignorance accounts for > your poor grasp of what I have been doing/saying. > Im explicating something about normal behaviour, not just delinquent or > pathological behaviour. You should look into the differences between rule > governed behaviour, and behaviour controlled by other contingencies - and > then think about this thread title. Think about your own NPD. > -- > David Longley === Subject: Re: More on the simple group of order 168 > I dont see why n_3 != 1 for N(I). > ----------------- > (some hand-waving and babbling follows) Again youre making things too hard. n_3 <> 1 for N(I) because we already showed that n_3 = 28 for G, so |N_G(P_3)| = 6, so G cant have a subgroup of order 24 with a normal subgroup of order 3. [...] -- Jim Heckman === Subject: Re: More on the simple group of order 168 <10pp3hvhlilbd33@corp.supernews.com> <10prdejast58lf5@corp.supernews.com> <10pto3od3jl6vf3@corp.supernews.com> posting-account=jcZk7AwAAADXpPEyHtVyWC264SxtppRB I seems so obvious when someone else says it. Clearly if P_3 normal in H, then H < N(P_3), which is impossible since |N_G(P_3)| = 6 and |H| = 24, as you say. That does n = 168. The original problem was to show that GL(3,2) was this simple group, by looking at characterictic polynomials, which will require further study before I can do it. Van === Subject: Re: More on the simple group of order 168 <10pp3hvhlilbd33@corp.supernews.com> <10prdejast58lf5@corp.supernews.com> <10pto3od3jl6vf3@corp.supernews.com> posting-account=jcZk7AwAAADXpPEyHtVyWC264SxtppRB I came across the following at a new URL for groups, at http://www.mathreference.com/grp-fin,g168.html I post it here since there has been a lot on the simple group of order 168. -------------- The Simple Group of Order 168 The simple group of order 168 can be described as a coliniation on 7 points. Label the points a through g and draw the triangle efg. Arrange abcd in a square and draw all 6 connecting edges. Then complete the following triangles. (efg) abe cde acf bdf adg bcg Thus e joins with 2 segments of the square to make two triangles, f joins with two segments, and g joins with two segments, covering all 6 segments. This graph is drawn for purposes of illustration. The coliniation is actually on triangles, not edges. If we were mapping edges to edges, the group would be S7. After all, we just drew a complete graph on 7 points. we might, for instance, map efg onto abc. However, abc is not one of the specified triples in our coliniation. The group consists of permutations that carry triples to triples, as listed above. Youll notice a symmetry among triangles. If abe were the main triangle, and cdfg the complete square, e connects to fg and cd, a connects to cf and dg, and b connects to df and cg. Our choice of abe was symbolically arbitrary. Any of the 7 triangles can act as the primary triangle, with 6 triangles connected to the remaining 6 edges. Use this to find the order of the group. Declare one of the 7 triangles as primary, and map efg onto that triangle in 6 different ways. Now, how many ways can we rearrange the square? We can swap a for b and c for d, or a for c and b for d. Thats a group of order 4. If a remains in position, b must as well, since there is no ace or ade triangle. Similarly, c and d are fixed. Once we know where a is, the square is established. Thus there are four ways to map abcd onto the complete square, once the primary triangle is selected. That gives a group of order 7[Times]6[Times]4 = 168. This group is a permutation group on 7 letters. Its order is divisible by 7, so it has an element of order 7, which is a 7 cycle. Two examples are: efdagcb and efbcgad. These 7 cycles map triples to triples, as listed above, and they are independent of each other. We can now prove the group is simple. Since g is transitive and 7 is prime, we can apply an earlier theorem. Thus every normal subgroup h of g contains all the elements of order 7. By the third Sylow theorem, the number of subgroups of order 7 is 1 mod 7, and divides 24. We produced two independent 7 cycles, so there must be 8 subgroups of order 7. These 8 groups define 48 elements of order 7, so |h| ñ 49. since |h| divides 168, it is either 84 or 56. If |h| = 84, then h cannot contain 8 instances of Z7 (third Sylow theorem). Thus |h| = 56. Since h has 8 elements not of order 7, these form the Sylow subgroup of order 8 in h. This 8-group does not contain the 7 cycles of g, and is not normal in g, hence there are other conjugates of this 8-group ßoating around, outside of h. Something in g/h has even order, yet |g/h| = 3. Therefore the subgroup h cannot exist, and g is a simple group. Sometimes g is presented as a permutation group on 7 letters, with a circular shift as a 7 cycle. recall our earlier 7 cycle efdagcb. Remap abcdefg to 0356142, and g contains the circular shifts of 0123456. If you relable the 7 triples, you get 013, 124, 235, 346, 450, 561, and 602. Thus the shift maps triples to triples, as it should. When we relable the permutations on the abcd square, we get the involutions 3210465 and 5126403. It is also possible to swap f and g, and c and d. This remaps to 0143265. Verify that these involutions map triples to triples, as they should. None of these three permutations is a circular shift of another. In fact these three involutions span a subgroup of order 8. Let r be the right circular shift, and let x y and z be our involutions, given below. Then verify the next three equations. x = 0143265 y = 3120465 z = 5126403 rrrrxrrrrrrxrrx = y rrrrrryrryrr = z rrrzrzrrrrrzr = x Any of the involutions, combined with the circular shift, generates the other two, and the group of order 8. Furthermore, zrzrr is an element of order 3. The group generated by the 7 cycle and any of these involutions is divisible by 7, 8, and 3, and is contained in our simple coliniation, hence it is the simple group of order 168. -------- Van === Subject: Re: (Possibly) New model of compution > I dont understand the first definition. you (I was wrong). Anyway, the bug is fixed. Please take another look at === Subject: Re: (Possibly) New model of compution > I dont understand the first definition. (I was wrong.) I believe that my definitions should now meet with your sasatisfaction. Please take another look at the paper. Sorry if this is a repost. Im not sure if the first one went through or not. === Subject: Re: (Possibly) New model of compution >> I dont understand the first definition. You seem to be defining BT >> via BT^2. What is BT^2 if not pair of elements from BT? You could >> before the formula Section 2 line 2, indicate that b is representing >> the colour (or color I suppose in American English) of the node x. >> I guess you are trying to use a recursive definition. > Yes I guess technically i have a circular definition. I should have said > let TT be the unique set S such that S={x | etc. }. Im pretty sure that > TT can be proven to exist in ZF. Anyway I more or less think you are > right. Even if TT does exist and behaves as i think it does its an awkward > formulation. I am going to take your advice and define things in the > manner you suggest. Actually, scratch what I said. I am not that used to actually properly defining reccursive sets. Im used to informal comp. sci. textbook type definitions. Upon reßection, I figure now that you were actually 100% right. I shouldnt have argued with you i guess but i never know who im arguing with on usenet. Anyway thank you very much for the advice. I do take advice and i am taking your advice. === Subject: Mathworld errors > I just got an email > inviting me to send him a list of errors on mathworld. > I havent saved such a list, thought Id mention this > in case anyone else has. >Recently, on sci.math, you mentioned: > <to believe, you might at least include a question mark or >something... >(Today must be your first visit to mathworld - its really full of >errors. I admit this is a good one.)>If you would be so kind as to send us a list, Eric and I will be >glad to fix them. >Ed Pegg Jr >MathWorld Associate > ************************ > David C. Ullrich If Eric invited/requested NG directly by posting here reg. errors,lists... === Subject: Re: Mathworld errors contd.. Two simple examples. For CornuSpiral Ces.88ro intrinsic equation rho = c^2/s,c is neither shown in figure nor explained,(as origin to pole coordinates along x- or y- ). The detail of KuenSurface endings appear distressingly conical due to a too coarse 3D parameter choice when it should be seem to be having a negative Gauss Curvature. === Subject: Re: Mathworld errors Ive found these quotes about mathworld. :mathworld has also blunders in basic combinatorics, etc. ... :For instance, look at the page about permanent of a matrix. :The closed formula for computing it is plain wrong!!! :When I mentioned that mathworld does not give a :single example of a T1 space which does not satisfy .... in response to my question ropestretcher spotted another typo: > http://mathworld.wolfram.com/UniversalSpace.html > How can we compute minimal d? > There seems to be a typo in the cited page - a metric > on R is a certain mapping of R x R to the nonnegative > reals, not a real number itself. In any event, it is > unlikely that there is a minimal d in any reasonable > sense of minimal because scaling a metric yields a > metric. ... There are probably other things in theory-edge. They should look themselves on individual math/theory forums on the web. They can ask, too. Its going to take their time, but its probably worth it. They can also put some bounties for errors on mathworld, in which case theyre going to see a huge list of legitimate errors in their inbox. (Now, I claim mine with this post :P ) -- Eray === Subject: Re: Mathworld errors > I just got an email > inviting me to send him a list of errors on mathworld. > I havent saved such a list, thought Id mention this > in case anyone else has. We had spotted some on theory-edge, too, but its so hard to tell. I believe Id tried to convince some people to report to mathworld, but they said the copyright terms were not good. Google is mathworlds friend of course. On theory-edge they must have a look at the following threads: Metric question t1 property mathworld post #9215 And probably other places as well, but these would be good places to start. Google does not seem to index theory-edge archives for some reason. At any rate... Hope this helps Ed. -- Eray Ozkural === Subject: Re: Mathworld errors Originator: harris@tcs.inf.tu-dresden.de (Mitchell Harris) >I believe Id tried to convince some people to report to mathworld, but >they said the copyright terms were not good. What do copyright terms have to do with reporting errors? >Google is mathworlds friend of course. How is that? Mitch === Subject: Re: Mathworld errors >I believe Id tried to convince some people to report to mathworld, but >they said the copyright terms were not good. > What do copyright terms have to do with reporting errors? Youll have to find those threads that I mentioned on theory-edge to see the arguments of those people. I dont know exactly. >Google is mathworlds friend of course. > How is that? They can search for discussions mentioning mathworld errors. -- Eray Ozkural === Subject: Re: Are Hilberts Axioms independent? |One feature of Hilberts book is that the axioms are not first order |axioms. So, the completeness theorem for first order logic doesnt apply |and it is at least conceivable that even if one axiom is independent of |the others, there might not exist a model in which it is false. There |might exist a model of set theory in which there is a model of geometry |in which it is false, but that is a much bigger problem than one normally |expects to have to deal with in confronting independence of axioms for |geometry. I dont think its customary to use the term independent to mean what youre using it to mean, for second-order axioms. Second-order logic has an associated satisfaction relationship between sentences and structures. We can define a consequence relation between sets of sentences and sentences by saying that a sentence A is a consequence of a family {B_i} of sentences if every structure satisfying all of the B_i also satisfies A. Trivially, if one of the axioms is a consequence in this sense of the others then it can be omitted without affecting which structures satisfy the axioms and conversely. The failure of the compleness theorem to apply means that there isnt a formal deductive system for second-order logic that suffices to deduce all the consequences of an arbitrary set of second-order axioms. As far as I know, in fact, there is no formal deductive system that is treated as standard for it. Consequently I would assume that there is no canonical notion of this sentence cannot be deduced in the canonical way from these other sentences, as distinct from this sentence is satisfied in all the structures where these other sentences are satisfied. It appears that you mean by independent that an axiom cannot be deduced (or refuted) from the remaining axioms in (some kind of) set theory. Its true that this entails only that there exists a model of that kind of set theory in which there is a structure satisfying the remaining axioms but not satisfying the independent one. But, correct me if I am wrong, I dont think the term independent is ordinarily used for that. |Incidentally, Marvin Greenbergs book on non-euclidean geometry makes |a fundamental mistake on this point and I think that greatly impairs its |usefulness as a textbook, in spite of its many admirable features. |Specifically, he claims that because of the Godel completeness theorem, |one is entitled to have a model of non-Euclidean geometry, including the |continuity axiom, if it is consistent, and organizes a certain amount of |the presentation around the belief that is true. Maybe this problem was |fixed in a later edition, but Im not aware of it. Thats too bad! If he meant to claim that the parallel axiom[*] is not a consequence of the others in the sense I defined above, then its tautological to say that there are non-Euclidean geometries; to show that there are non-Euclidean geometries is what one would need to do to prove that the parallel axiom is not a consequence of the other axioms. The Goedel completeness theorem doesnt enter into it. It seems like sort of an odd statement anyway. Even if it were only a question of the first-order axioms, the easiest way to show that there is no proof (in a standard deductive system for first-order logic) of the parallel axiom[*] from the remaining axioms is to exhibit a model, isnt it? [*] Or whatever distinguishes Euclidean from non-Euclidean in his system. Keith Ramsay === Subject: Most Distorted Triangle > Is there a most scalene/ asymmetric/distorted triangle, most remote > from the equilateral triangle? If so, what may be a proper criterion > or definition of asymmetry? > . . . Yes there is. Squared lengths ratios are: 1 : 4+sqrt(15) : (5+sqrt(15))/2 Theory, criterion, etc..: see my web site. Michel Petitjean, Email: petitjean@itodys.jussieu.fr ITODYS (CNRS, UMR 7086) ptitjean@ccr.jussieu.fr http://petitjeanmichel.free.fr/itoweb.petitjean.html === Subject: Re: How to apply a filter on raw data... It sounds like an cellular automata like a Majority function used in image processing might be your answer. There also several edge finder algorithms of this type as well. you get the idea): http://www.nd.edu/~mtns/papers/17761_4.pdf >Hallo to everyone, >Im trying for the last 2 weeks to find a way to apply a filter on raw >data. The raw data consists of matrices with surface topography >values. For example I have a matrix R with size(R) = [512 512] and I >want to apply a filter in order to find the low pass component >surface and the high-pass component surface. I have tried with >matlab using the commands filter2, conv2, but frankly speaking, this >is the first time I have to use such methods and I have no experiance >whatsoever of what to expect as a result... Can someone here help >me... It would really help if someone could explain to me what to do >in order to do the filtering. Im using the gauss (normal) >distribution as a filter. If anyone is interested I can send the >matlab program. >Yannis -- Respectfully, Roger L. Bagula tftn@earthlink.net, 11759Waterhill Road, Lakeside,Ca 92040-2905,tel: 619-5610814 : alternative email: rlbtftn@netscape.net URL : http://home.earthlink.net/~tftn === Subject: Re: How to apply a filter on raw data... Hallo Roger, thank you very much for your answer. I dont think is what you suggest, is what I need. All I need is someone to tell me the necessery steps taken in order to do a succesfull filtering of raw data concerning the topography of a surface. I have no idea what to do with edge finding algorithms... Bye Yannis > It sounds like an cellular automata like > a Majority function used in image processing > might be your answer. > There also several edge finder algorithms of this type as well. > you get the idea): > http://www.nd.edu/~mtns/papers/17761_4.pdf >Hallo to everyone, >Im trying for the last 2 weeks to find a way to apply a filter on raw >data. The raw data consists of matrices with surface topography >values. For example I have a matrix R with size(R) = [512 512] and I >want to apply a filter in order to find the low pass component >surface and the high-pass component surface. I have tried with >matlab using the commands filter2, conv2, but frankly speaking, this >is the first time I have to use such methods and I have no experiance >whatsoever of what to expect as a result... Can someone here help >me... It would really help if someone could explain to me what to do >in order to do the filtering. Im using the gauss (normal) >distribution as a filter. If anyone is interested I can send the >matlab program. >Yannis > === Subject: Re: Derivative of maximum eigenvalue of a matrix. Sir, thank you very much. You gave me a very good idea to solve this. === Subject: Re: hard matrix inversion... > Okay, so for these kind of special matrices, it is good to plug in Matlab > and find some special cases for n is small, etc... Yes, thats a good way to find patterns. I believe thats how Euler did it, but, umm, Im not a math historian. > But to prove the pattern in general? > It seems to me the proof of the inverse matrix has some pattern is very > difficult? Maybe use induction on matrix inversion? Not sure how to do > induction on matrix inversion? > Maybe I can divide a matrix into > [A B > C D] > where A is a sub-matrix, D is just 1x1 element, I am not sure what is the > inversion of the above block matrices in terms of A B C D? Are you familiar with The Simpsons? You know how Homer often whacks his forehead and says Dohh!? Get ready to do that. A good way to prove that some matrix B is the inverse of a matrix A is to show that BA = I. There is a principle here which is applicable to other branches of math. For example, if youre asked to show that y=e^x is a solution to dy/dx = y, your first thought should not be Hmmm, should I solve it as a separable or as a linear equation? === Subject: Re: hard matrix inversion... >Also, Det(a) = (1-a^2)^n, but the eigenvalues and eigenvectors do not >simplify to anything nice. (The characteristic polynomial seems to >have a nice pattern though.) > The characteristic polynomial P(t) = Det(A-tI) seems to always factor as > a product of two polynomials whose degrees are either n/2 and n/2 (if n is > even) or (n-1)/2 and (n+1)/2 (if n is odd). In the even case, one > polynomial is obtained from the other by the substitution a -> -a. > In the odd case, both factors contain only even powers of a. > Otherwise I dont quite see the pattern. I dont quite see the pattern either, but I a can smell it. If you look at it like this (i.e., essentially this just divides out factors of (1-a^2) from the coefficients of the characteristic polynomial) p[n_] := Det[Table[a^Abs[i-j], {i,0,n}, {j,0,n}] - t IdentityMatrix[n+1]]; q[n_] := Factor /@ (Take[CoefficientList[p[n], t], n+1] / Table[(-1)^i(1-a^2)^(n-i), {i,0,n}]); r[n_] := Table[Coefficient[q[n][[j]],a,2k], {j,n+1}, {k,0,n}] // MatrixForm; you get this: In[1]:= r[6] Out[1]= 1 0 0 0 0 0 0 7 5 0 0 0 0 0 21 24 10 0 0 0 0 35 45 30 10 0 0 0 35 40 30 16 5 0 0 21 15 10 6 3 1 0 7 0 0 0 0 0 0 There are familiar patterns on various rows, columns and diagonals. The real kicker is that, as far as I can tell, no coefficient is ever divisible by a prime factor > n+1. So I think there must be a simple formula. I havent found it, though. -Jim Ferry === Subject: Counterexample to t( (c^n - a^n) mod b ) | phi(b) I have located a counterexample to the seemingly obvious assertion that since the component pure exponential generators (c^n) mod b and (a^n) mod b in the dual subtractive exponential generator with gcd(a,b,c)=1 and a n has a factor of two or more, contradicting n=p, but you see, I dont really understand n=p, I just sort of follow that if a^mp+ b^mp=c^mp that of course (a^m)^p+(b^m)^p=(c^m)^p. please, do so and write here. Certainly it is obvious to me that if gcd(a,b,c)=1 then gcd(a^m, b^m, c^m) =1. That much is clear. I tolerance everything and tolerate everyone. I love: Dona, Jeff, Kim, Kimmie, Mom, Neelix, Tasha, and Teri, alphabetically. I drive: A double-step Thunderbolt with 657% range. I fight terrorism by: Using less gasoline. === Subject: Re: Counterexample to t( (c^n - a^n) mod b ) | phi(b) > I have located a counterexample to the seemingly obvious assertion that since > the component pure exponential generators > (c^n) mod b and (a^n) mod b > in the dual subtractive exponential generator with gcd(a,b,c)=1 and a (c^n - b^n) mod b > have periods that divide phi(b), it must be true that the period of the dual > generator also divides phi(b). > The counterexample is a=5,b=6, c=7. ph(b)=3 and > t( (c^n - a^n) mod b ) = 2. > I have more counterexamples if needed. phi(b) = 2. -- ... one Marine noticed one of the prisoners was still breathing. A Marine can be heard saying on the pool footage provided to Reuters Television: Hes ing faking hes dead. He faking hes ing dead. The Marine then raises his riße and fires into the mans head. The pictures are too graphic for us to broadcast, Sites said. === Subject: Re: Counterexample to t( (c^n - a^n) mod b ) | phi(b) phi(6)=2 (5 and 1 do not divide 6) error in function phi(n) in Mathcad document cf NB times NA, N = 1.mcd. Its written correctly. My other group is reminding me I am writing a bit stressed. ÔTil after the holiday, then. I tolerance everything and tolerate everyone. I love: Dona, Jeff, Kim, Kimmie, Mom, Neelix, Tasha, and Teri, alphabetically. I drive: A double-step Thunderbolt with 657% range. I fight terrorism by: Using less gasoline. === Subject: Re: Counterexample to t( (c^n - a^n) mod b ) | phi(b) >phi(6)=2 (5 and 1 do not divide 6) Neither does 4. I just misspelled ph(b)=3, it wasnt calculated correctly. So does the period of (c^n-a^n) mod b divide phi(b) or doesnt it? I say it doesnt always divide phi(b). I tolerance everything and tolerate everyone. I love: Dona, Jeff, Kim, Kimmie, Mom, Neelix, Tasha, and Teri, alphabetically. I drive: A double-step Thunderbolt with 657% range. I fight terrorism by: Using less gasoline. === Subject: Re: Counterexample to t( (c^n - a^n) mod b ) | phi(b) >phi(6)=2 (5 and 1 do not divide 6) > Neither does 4. > I just misspelled ph(b)=3, it wasnt calculated correctly. > So does the period of (c^n-a^n) mod b divide phi(b) or doesnt it? > I say it doesnt always divide phi(b). I say youre wrong. c^(n+phi(b)) - c^n is a multiple of b (for sufficiently large n in the case that gcd(b,c) > 1). The same is true of a^(n+phi(b)) - a^n. Therefore (c^(n+phi(b)) - a^(n+phi(b))) - (c^n - a^n) is a multiple of b. Therefore (c^(n+phi(b)) - a^(n+phi(b))) mod b = (c^n - a^n) mod b If that doesnt establish that the period of (c^n - a^n) mod b is a factor of phi(b), what does? -- Daniel W. Johnson panoptes@iquest.net http://members.iquest.net/~panoptes/ 039 53 36 N / 086 11 55 W === Subject: Re: Counterexample to t( (c^n - a^n) mod b ) | phi(b) >c^(n+phi(b)) - c^n is a multiple of b (for sufficiently large n in the >case that gcd(b,c) > 1). This seems to be a misapplication of Eulers totient theorem, that for relatively prime a and n a^(phi(n)) == 1 mod n Is it? We dont need to consider the case gcd(b,c)>1. gcd(a,b,c)=1 is given in the OP to this thread. Given b | c^(n+phi(b))-c^n, what you say would be true. Whence cometh this assertion? Its as if you are implying c^(n+phi(b)) - c^n = c^(phi(b)) and we know this cant be true because while subtraction is associative under multiplication, it is not associative under exponentiation. The counter example a,b,c = 5,6,7 shows that the period of c^n - a^n (mod b) does not necessarily divide phi(b). >The same is true of a^(n+phi(b)) - a^n. >Therefore (c^(n+phi(b)) - a^(n+phi(b))) - (c^n - a^n) is a multiple of >Therefore (c^(n+phi(b)) - a^(n+phi(b))) mod b = (c^n - a^n) mod b >If that doesnt establish that the period of (c^n - a^n) mod b is a >factor of phi(b), what does? Nothing does. I argued the same way to myself, that the period of the component exponential generators c^n mod b and a^n mod b | phi(b), and so t(c^n - a^n (mod b)) | phi(b). It simply isnt true. Yes, 0-0=0, but for some other n, b | c^n - a^n. Theres no reason these two powers cant combine with subtraction because subtraction doesnt associate with exponentiation. (cn - an) = (c-a)n but (c^n - a^n) != (c-a)^n multiplication does associate with exponentation: (c^n * a^n) = (ca)^n thats what makes FLT such a hard nut to crack. I tolerance everything and tolerate everyone. I love: Dona, Jeff, Kim, Kimmie, Mom, Neelix, Tasha, and Teri, alphabetically. I drive: A double-step Thunderbolt with 657% range. I fight terrorism by: Using less gasoline. === Subject: Re: Counterexample to t( (c^n - a^n) mod b ) | phi(b) >c^(n+phi(b)) - c^n is a multiple of b (for sufficiently large n in the >case that gcd(b,c) > 1). > This seems to be a misapplication of Eulers totient theorem, that for > relatively prime a and n > a^(phi(n)) == 1 mod n > Is it? > We dont need to consider the case gcd(b,c)>1. gcd(a,b,c)=1 is given in the OP > to this thread. Right. You gave gcd(a,b,c)=1. You did not give gcd(a,b)=gcd(a,c)=gcd(b,c)=1. Consider a=6, b=10, c=15. Then gcd(b,c)=5 but gcd(a,b,c)=1. > Given b | c^(n+phi(b))-c^n, what you say would be true. Whence cometh this > assertion? Its as if you are implying > c^(n+phi(b)) - c^n = c^(phi(b)) No. Eulers totient theorem gives us b | c^(phi(b)) - 1 Since c^(n+phi(b))-c^n = c^n*(c^(phi(b)) - 1), the result is immediate. > The counter example a,b,c = 5,6,7 shows that the period of > c^n - a^n (mod b) > does not necessarily divide phi(b). Thats not a counterexample, as has already been pointed out to you. 7^n - 5^n (mod 6) is 0 for even n and 2 for odd n. Thats periodic with a period of 2, just like 5^n mod 6, and 2 divides phi(6) = 2. (7^n mod 6 actually has a period of 1.) >The same is true of a^(n+phi(b)) - a^n. >Therefore (c^(n+phi(b)) - a^(n+phi(b))) - (c^n - a^n) is a multiple of >b. >Therefore (c^(n+phi(b)) - a^(n+phi(b))) mod b = (c^n - a^n) mod b >If that doesnt establish that the period of (c^n - a^n) mod b is a >factor of phi(b), what does? > Nothing does. I argued the same way to myself, that the period of the > component exponential generators c^n mod b and a^n mod b | phi(b), and so > t(c^n - a^n (mod b)) | phi(b). It simply isnt true. Yes, 0-0=0, but for > some other n, b | c^n - a^n. Theres no reason these two powers cant > combine with subtraction because subtraction doesnt associate with > exponentiation. > (cn - an) = (c-a)n but > (c^n - a^n) != (c-a)^n > multiplication does associate with exponentation: > (c^n * a^n) = (ca)^n Multiplication does distribute over subtraction, which is all that matters. More generally, suppose f(n) and g(n) both have periods that divide k. In other words, f(n+k) - f(n) and g(n+k) - f(n) are 0 for all n. In this case, f(n) = c^n mod b and g(n) = a^n mod b, and the period k is phi(b). Define h(n) = f(n) - g(n). We then have, for all n: h(n+k) - h(n) = (f(n+k) - g(n+k)) - (f(n) - g(n)) = f(n+k) - f(n) - g(n+k) + g(n) = (f(n+k) - f(n)) - (g(n+k) - g(n)) = 0 - 0 = 0 Q.E.D. -- Daniel W. Johnson panoptes@iquest.net http://members.iquest.net/~panoptes/ 039 53 36 N / 086 11 55 W === Subject: Re: Counterexample to t( (c^n - a^n) mod b ) | phi(b) >phi(6)=2 (5 and 1 do not divide 6) > Neither does 4. > I just misspelled ph(b)=3, it wasnt calculated correctly. > So does the period of (c^n-a^n) mod b divide phi(b) or doesnt it? > I say it doesnt always divide phi(b). Dont just say, prove. (17:38) gp > for(a=0,5,for(b=0,5,print1(a b : );for(n=1,6,print1( (a^n-b^n)%6));print())) 0 0 : 0 0 0 0 0 0 0 1 : 5 5 5 5 5 5 0 2 : 4 2 4 2 4 2 0 3 : 3 3 3 3 3 3 0 4 : 2 2 2 2 2 2 0 5 : 1 5 1 5 1 5 1 0 : 1 1 1 1 1 1 1 1 : 0 0 0 0 0 0 1 2 : 5 3 5 3 5 3 1 3 : 4 4 4 4 4 4 1 4 : 3 3 3 3 3 3 1 5 : 2 0 2 0 2 0 2 0 : 2 4 2 4 2 4 2 1 : 1 3 1 3 1 3 2 2 : 0 0 0 0 0 0 2 3 : 5 1 5 1 5 1 2 4 : 4 0 4 0 4 0 2 5 : 3 3 3 3 3 3 3 0 : 3 3 3 3 3 3 3 1 : 2 2 2 2 2 2 3 2 : 1 5 1 5 1 5 3 3 : 0 0 0 0 0 0 3 4 : 5 5 5 5 5 5 3 5 : 4 2 4 2 4 2 4 0 : 4 4 4 4 4 4 4 1 : 3 3 3 3 3 3 4 2 : 2 0 2 0 2 0 4 3 : 1 1 1 1 1 1 4 4 : 0 0 0 0 0 0 4 5 : 5 3 5 3 5 3 5 0 : 5 1 5 1 5 1 5 1 : 4 0 4 0 4 0 5 2 : 3 3 3 3 3 3 5 3 : 2 4 2 4 2 4 5 4 : 1 3 1 3 1 3 5 5 : 0 0 0 0 0 0 Either constant (period 1) or alternating (period 2). Phil -- ... one Marine noticed one of the prisoners was still breathing. A Marine can be heard saying on the pool footage provided to Reuters Television: Hes ing faking hes dead. He faking hes ing dead. The Marine then raises his riße and fires into the mans head. The pictures are too graphic for us to broadcast, Sites said. === Subject: Re: Counterexample to t( (c^n - a^n) mod b ) | phi(b) >Dont just say, prove. Good advice. a b c (c^n - a^n) mod b 5 6 7 0 2 0 2 0 2... period is two (2). The totatives of b=6 are 1, 4, and 5. 1 has no factor and can have no factor in common with 6. phi(6) = 3. The period of the dual subtractive exponential generator with gcd(a,b,c)=1 and a blithered: >Dont just say, prove. > Good advice. > a b c (c^n - a^n) mod b > 5 6 7 0 2 0 2 0 2... > period is two (2). > The totatives of b=6 are 1, 4, and 5. 1 has no factor and can have no > factor in common with 6. phi(6) = 3. gcd(4,6) = 2 > 1. 4 is not a totative of 6. So, what is 5^phi(6) mod 6 ? -- Daniel W. Johnson panoptes@iquest.net http://members.iquest.net/~panoptes/ 039 53 36 N / 086 11 55 W === Subject: Re: new twist to the Crossover Technique of the VonNeumann Gametheory in playing StockMarket; BCE, SBC, drug companies I did not talk about the new twist very much. So let me detail it further. When I started the PAF portfolio in October of 2002 I was immediately challenged with a Crossover technique applied to Verizon and Wyeth. If my memory serves me correctly, these two stocks were in the general price range of about $32 to $35 a share and one day Wyeth would be 32 and Verizon be 35 and a couple of weeks later VZ be 32 and Wyeth be 35 allowing me to sell one and buy the other and gain in total number of shares and this switching campaign lasted for several months. In every switch Crossover, the extra shares are like getting something for free (before taxes of course). Then I remember the switching Crossover campaign between BMY and SBC and that lasted for several months. But the trouble is that the Crossovers last only brießy before one partner of a switching campaign zooms ahead and stays ahead for years at a time. One of the very best examples of Crossover Switching Campaigns for the last 5 years has been SBC and BLS. In fact if I were forced to stick to just 2 stocks to run the switching for the 1990s and up to 2005 it would have probably, no doubt, been SBC and BLS. For most of 1990s SBC has been priced above BLS but around 2001 and thereafter BLS has traded about 1 to 2 dollars higher than SBC. Today SBC is about $26.50 and BLS is about $28. So an astute Crossover Switch player could have just profited both in terms of increasing number of total shares in the portfolio by taking advantage of price discrepancies between SBC and BLS but also increased in terms of extra cash in the switches as well as happy over the steady dividends every 3 months. But again the main trouble with Crossover Switches is that they come few and far between. I remember the Crossover of Verizon to SBC way back years ago. Verizon usually trades about $10 premium above SBC but many years ago there was a union strike at VZ to where its price dropped below that of SBC. In those days VZ and SBC were trading around 40 to 52 dollars per share and VZ dropped to around 44 and SBC kept rising to over 52. So that was a glorious Crossover to have made. Then again, I probably should be trading less in the portfolio and just sit back and wait for years to move by and then jump in with a crossover such as VZ to SBC when they Crossover in a big manner. But the new twist that I have recently learned is that of applying the Crossover not just to 2 companies such as Wyeth to VZ or BMY to SBC or BLS to SBC. Instead, apply the Crossover to 1 company and to cash. If you watch stocks as much as I do, that is track them for every day for years at a time or even decades then, we trackers or fellow trackers, soon develop a sense of the price going too high for what it is worth. Not only the stocks we track but other stocks such as for example does anyone really believe that Microsoft is worth over 300 billion in capitalization or does anyone really believe Pfizer should be worth nearly 300 billion in capitalization when its brethren of Merck fell to 60 billion with one fiasco of Vioxx. Does anyone really believe that Lipitor and Celebrex is worth 300 billion in capitalization when Sanofi has a drug that promises to lose weight as well as reduce cholesterol. So what I am saying is that playing the Crossover, such as yesterday there was a clearcut crossover of BCE with BMY in that BCE was trading at 24.30 and BMY was trading at 24.15 and that was the first Crossover of BCE to BMY in the last 3 or 4 or 5 or even more years. Perhaps I should have taken advantage of that Crossover and sold some BCE to buy BMY but I doubt it because the entire drug industry is clouded by Vioxx. So the new partner to Crossover Switching is Cash. Where I feel a company has gone ahead too fast and too steep of a price that I sell a chunk and sit in cash for days or several weeks and then hopefully buy back the same company at a more reasonable price. For instance, Verizon is overpriced and so is Microsoft and so was the oil companies during the recent run up in oil where it went over $50 a barrel. So I need to augment the clearcut Crossover of say company A going higher than company B and weeks later Company B going higher than Company A and switching back having profited with more shares than originally. Augment that Crossover with Company X and cash. So if I feel Company X has priced itself too high, then sell a chunk, sit back and wait and hopefully it drops enough in price to rebuy and profit with more shares plus cash extras. So the new twist is to augment the Crossover Switch Campaign with Company X and cash alongside the clearcut Crossover Switch Campaign between Company A and Company B. Archimedes Plutonium www.iw.net/~a_plutonium whole entire Universe is just one big atom where dots of the electron-dot-cloud are galaxies === Subject: Re: a question on continuous functions, please help... at 01:40 PM, kinki_best@hotmail.com (mindy) said: >Let f: R-> R be continuous on R. Given a,b in R, a=set A = {x in R: a =< f(x) =< b}. Show that if (x_1, x_2, x_3,...) >is a sequence in A that converges to a number x, then x lies in A. >My thoughts: Since f is continuous on R, (x_1, x_2, x_3,....) >converges to x implies (f(x_1), f(x_2), f(x_3),...) converges to >f(x). Then I have no idea what to do next. Please enlighten. Apply the Triangle Inequality and the definiyion of convergence. -- Shmuel (Seymour J.) Metz, SysProg and JOAT Unsolicited bulk E-mail subject to legal action. I reserve the right to publicly post or ridicule any abusive E-mail. Reply to domain Patriot dot net user shmuel+news to contact me. Do not === Subject: Re: Predicting the Stockmarket throughout the 21st century > You need to read from the wise book that says that when someone is > working on > an idea that the wise person looks for true bits and pieces. Whereas the > dumb > guy jumps into the discussion with attack, attack and attack. > Looking at a rise in population as the development of modern civilization is > interesting. > But China is developing into a middle-class society while controlling > population. India is just as smart and a thousand years from now Africa may > be developing into a middle-class society. So this is an idea of the > development of existing populations... > Economics is a major discipline with multiple levels of fundamentals. The > fundamentals truly coorelate and fail to truly coorelate all over the map. I > just mention productivity, development of new technology, and development of > existing populations. Well I am thinking that a Barrier Concept exists for the StockMarket. We know and agree that oil is finite so there is a barrier to oil in that once we find the last of it and use it up, we have to make it artificially. We know that human population is finite and that once we fill this planet there comes a moment where we cannot add one more single person. We know that gold on Earth is finite and that it is neither created or destroyed (in practice) and so gold and oil and number of humans is finite and have a barrier. But now let us look at the StockMarket. Is it infinite? Does it have no barrier? Is it different from oil from gold and from the number of humans? Those questions suggest to me that the StockMarket is just a passing phenomenon. I would not call it a fade of history for it is stronger than a passing fade or trend. It certainly has its mark on history but I suspect that in a few future centuries from now that the StockMarket will be nothing that we recognize today. I suspect that the Bond Market of today will be the StockMarket of the future. And that the StockMarket we recognize today will have become defunct. Because in a sense, the reason you have a 10 fold increase in DJIA, and a 10 fold increase in price of gold and a 10 fold increase in human population from day in work and someone in New York City raking in $1 million per day from trading stocks. The poorness of billions of humans is at the expense of a few who simply lavish in riches and do nothing but place a trade order and rake in millions. The reason DJIA went 10 times and gold went 10 times is because human population went 10 times over that period of history. But the spread of that of Africa, Asia, South America payed the price. The StockMarket is an avenue of siphoning off the wealth of continents and placing it into the hands of a few. In that sense, the StockMarket of today is doomed to become something unrecognizable in future centuries. We see it already in GlobalWarming that we cannot increase human population. We see it in the fact that today it was announced that 10,000 species including sharks, turtles, fir trees, frogs are going extinct. The StockMarket as set up today increases GlobalWarming. Increases human overpopulation. Increases extinctions of species. Archimedes Plutonium www.iw.net/~a_plutonium whole entire Universe is just one big atom where dots of the electron-dot-cloud are galaxies === Subject: help! a probablilty problem about ßipping coins... Suppose we ßip a unfair coin with prob. p it is head, with prob. 1-p it is tail. So the prob. of head is p, a prior probablity. I ßip the coin N times, what is the a posterprior prob. of head if I know that there are at least K heads? i.e. given at least K heads? what is the prob. of getting M heads out of these N ßippings given at least K heads occurred? === Subject: Re: help! a probablilty problem about ßipping coins... > So the prob. of head is p, a prior probablity. Note that typically we apply the term prior in a different sense. It is a probability density function of the possible values of some unknown parameter. If in this case the parameter is Pr(H), then our knowledge that Pr(H) = p can be expressed as a prior pdf over the possible values of this probability: f(w) = delta(w-p) . Back to the problem now. If we are unshakeably sure about the value of Pr(H) (as you assume) then we cannot learn anything from the data. ~ George Kahrimanis === Subject: Re: help! a probablilty problem about ßipping coins... >> So the prob. of head is p, a prior probablity. > Note that typically we apply the term prior in a different > sense. It is a probability density function of the possible values > of some unknown parameter. > If in this case the parameter is Pr(H), then our knowledge that > Pr(H) = p can be expressed as a prior pdf over the possible > values of this probability: f(w) = delta(w-p) . > Back to the problem now. If we are unshakeably sure about the > value of Pr(H) (as you assume) then we cannot learn anything from > the data. > ~ George Kahrimanis What if the bias P is a random variable and we dont know P... So from data -- given that at least K ßips are heads -- ... we should learn something about P... === Subject: Re: help! a probablilty problem about ßipping coins... >So the prob. of head is p, a prior probablity. >>Note that typically we apply the term prior in a different >>sense. It is a probability density function of the possible values >>of some unknown parameter. >>If in this case the parameter is Pr(H), then our knowledge that >>Pr(H) = p can be expressed as a prior pdf over the possible >>values of this probability: f(w) = delta(w-p) . >>Back to the problem now. If we are unshakeably sure about the >>value of Pr(H) (as you assume) then we cannot learn anything from >>the data. >>~ George Kahrimanis > What if the bias P is a random variable and we dont know P... > So from data -- given that at least K ßips are heads -- ... we should learn > something about P... This should be covered in any basic book on Bayesian analysis: if you knew that exactly K ßips were heads, then it would be about the simplest example of using Bayesian probability as a model of learning. The rest is just mathematics. Bob -- Bob OHara Dept. of Mathematics and Statistics P.O. Box 68 (Gustaf H.84llstr.94min katu 2b) FIN-00014 University of Helsinki Finland Telephone: +358-9-191 51479 Mobile: +358 50 599 0540 Fax: +358-9-191 51400 WWW: http://www.RNI.Helsinki.FI/~boh/ Journal of Negative Results - EEB: http://www.jnr-eeb.org === Subject: Re: help! a probablilty problem about ßipping coins... >Suppose we ßip a unfair coin with prob. p it is head, with prob. 1-p it is >tail. >So the prob. of head is p, a prior probablity. >I ßip the coin N times, >what is the a posterprior prob. of head if I know that there are at least K >heads? i.e. given at least K heads? >what is the prob. of getting M heads out of these N ßippings given at least >K heads occurred? The probability of exactly M heads is given by the binomial distribution. P(M) = p^M * (1-p)^(N-M) * choose(N,M) The probability of event A given event B is: P(A|B) = P(A&B) / P(B) [The | character means given in this context; & means and] That should get you started. --Keith Lewis klewis {at} mitre.org The above may not (yet) represent the opinions of my employer. === Subject: Re: help! a probablilty problem about ßipping coins... > Suppose we ßip a unfair coin with prob. p it is head, with prob. 1-p > it is > tail. > So the prob. of head is p, a prior probablity. > I ßip the coin N times, > what is the a posterprior prob. of head if I know that there are at > least K > heads? i.e. given at least K heads? > what is the prob. of getting M heads out of these N ßippings given at > least K heads occurred? Fellers book, Vol. 1. John Lowry Flight Physics (and former geneticist) === Subject: Inversion of complicated Laplace transform Im trying to obtain the inverse Laplace transform of the following expression: ( 400 * (10 + Sqrt(15 + 300*s)) ) / ( 10410 + 41*Sqrt(15 + 300*s) + 40*s^2*(10010 + Sqrt(15 + 300*s)) + 22*s*(10210 + 21*Sqrt(15 + 300*s)) ) It appears as if the usual factorization of the denominator does not apply here due to the appearance of the Sqrt(15 + 300*s) terms. Any ideas? In principle, an asymptotic expansion valid for long t would suffice. Im thankful for every proposal that would help to avoid a numerical inversion. Johan === Subject: Re: Inversion of complicated Laplace transform Hi Johan, I hab a look at your function. Since it is not the usual rational function, one has to look at the expansions of it at the zeros of the denominator with the largest real parts to get an asymptotic expansion. I tried a little bit; a further problem here is that it looks to me that these zeros are two conjugate zeros very near. The expansions are different, if one has two zeros or if they coalesce into one point. First case gives here something like t^{-1/2}exp(-at) with a the real part of the zeros or exp(-at) if they coalesce into one. (see f.e. G. Doetsch, Intro t. t. Theory and Appl. o. t. Laplace transform, Springer, 1974). Any ideas which might be the right order of magnitude in your case? Ciao Karl > Im trying to obtain the inverse Laplace transform of the following > expression: > ( 400 * (10 + Sqrt(15 + 300*s)) ) / > ( 10410 + 41*Sqrt(15 + 300*s) + 40*s^2*(10010 + Sqrt(15 + 300*s)) + > 22*s*(10210 + 21*Sqrt(15 + 300*s)) ) > It appears as if the usual factorization of the denominator does not > apply here due to the appearance of the Sqrt(15 + 300*s) terms. Any > ideas? In principle, an asymptotic expansion valid for long t would > suffice. Im thankful for every proposal that would help to avoid a > numerical inversion. > Johan === Subject: astonishingly many numbers with abundace 12 and 56 hi, im currently writing a text about perfect numbers and many things related to it for my final school exam. in order to get an idea of how the whole thing isnt good enough) which are supposed to tell me how many numbers are perfect, abundant, deficient, and similar things. what i got was a frighteningly long list of numbers, so i visualized it using gnuplot. the results were surprinsing for me. i knew from books that there is just a little amount of perfect numbers, there are several numbers with deficiency 1 and none with abundance 1 (plz correct me if i use wrong terms, english is not my mother tongue). but it struck me how many numbers there are with an abundance of 12 and 56. observing integers from 1 to 100,000, i found 505 numbers abundant by 56 and even 1929 numbers abundant by 12. this is especially astonishing as the next frequent abundance is 992, found in just 47 numbers in the observed range, all the others only occur 21 times or even rarer. i tried to find out why i get such extreme values, but didnt find anything. if anyone wants to have a look at it, i can post the scripts (unfortunately, not knowing that i would ask here, variable and function names are german) or gnuplot plots (please tell me which format you prefer). if you have any idea why these things are as they are, please let me know! btw: i also let gnuplot draw a diagram with N on the x-axis and sigma(N)-n on the y-axis. drawing everything from 1 to 50,000, the accumulations of points on y=x+12 and y=x+56 are invisible, but several other Ôlines, i.e., accumulations of abundancies as a linear function of n, are, which resemble functions of simple fractions of x. these are just special ones -- i couldnt find out which until now; y=1/2*x and y=3/4*x are such lines, y=2/3*x isnt. i could send images of that as well. greetings webograph === Subject: Re: astonishingly many numbers with abundace 12 and 56 format=ßowed; reply-type=response