mm-77 == Say curve Ked quadraticly by (from random sets of (x,y)in space)parabola A that concave up for x= a to bparabola B that concave down for x = b to cThe two parabolas join smoothly at b with continuous ?st degreederivative.At b, C changes concavity, which suddenly causes the tangent vectorsto be ?mirrored against the curve. (Graphicly, instead of beingalways above parabola A, now the tangents are always below parabola B)This causes problem for me because in 3d, the Normal calculated fromthe Tangent suddenly become mirrored against the curve. (from the TNBcoordinates view, everything is now upside down after passing thechange in concavity).Basicly I need an interpolation method that prevents the TNB system === Well, you sound like you want to suck Shaq off, and are jackin yourload over getting payton and malone. I AM FROM hollywood unlike youhillbilly types.Dont shoot your load too soon. You got the porno on your webtvsystem I bet, so you cant even claim ignorance. But claim something,cause your usenet post just sucked rats ass.Perhaps you would like to suck Ronald Reagans cock === ermmmthis post is very nice. only an artist can appreciate this kind of work.hahahahahaha> Well, you sound like you want to suck Shaq off, and are jackin your> load over getting payton and malone. I AM FROM hollywood unlike you> hillbilly types.>> Dont shoot your load too soon. You got the porno on your webtv> system I bet, so you cant even claim ignorance. But claim something,> cause your usenet post just sucked rats ass.>> Perhaps you would like to suck Ronald Reagans cock === > Well, you sound like you want to suck Shaq off, and are jackin your> load over getting payton and malone. I AM FROM hollywood unlike you> hillbilly types.> > Dont shoot your load too soon. You got the porno on your webtv> system I bet, so you cant even claim ignorance. But claim something,> cause your usenet post just sucked rats ass.> > Perhaps you would like to suck Ronald Reagans cock> Dont you love it when someone makes a post like this but leaves out all the attribution. AOL - still a bastion of idiocy.-- Go Yankees!Go Lakers!!Go Rangers!Go Giants!! Fire Fassle NOW!!!This is very upsetting to me (j/k, mostly) but I just cannot seem to reallyUNDERSTAND why a number with an irrational exponent exists. I believe itstrue, because people much smarter than me say it is, but I dont see why. Howcan 2 ^ pi, for example, be a number? What does 2 ^ pi MEAN? 2 ^ 0.713 meansthe thousandth root of two ^ 713. But if the exponent is irrational, isnt itmeaningless?Its been explained to me that since you can get closer and closer to thenumber without reaching it (2^3.14, 2^3.141, 2^3.1415...) it must exist sinceotherwise it would cause a hole in the rationals...but how can an utterlymeaningless symbol like 2^pi be a hole? They see a hole, because it doesntEXIST and they want it to exist. (Like I said, I DO believe them, I just dontErin === Do you know calculus?Take a constant a, and imagine an object moving on the real line sothat its position x(t) at time t obeys x(t) = a x(t), with startingvalue x(0)=1. That is, the velocity is proportional to the coordinate.[Imagine a race-car driver starting at marker 1 meter going at speed 1meter per second; when he reaches marker 10 meters, he should be goingat speed 10 meters per second; when he reaches marker 20 meters, heshould be goint at speed 20 meters per second; and so on. I used a=1in this example.]Then the position at time t will be exp(at). That is the MEANING ofexp(at). If we take the value a so that x(1) = 2, that is exp(a) = 2,we call that value a=ln(2). Using this value we have x(t) = exp(at) =2^t for integer (or rational) t, so take this differential equation asthe MEANING of 2^t for ALL values of t. If time pi makes sense, then2^pi is the location of the race-car at that time.Does that help? If you dont know calculus, perhaps you will just haveto wait. Every calculus text has a section on exponential growth anddecay.As an aside: Sometimes people are confused by COMPLEX NUMBERS asexponents. Well, the same differential equation method works toexplain them, too.-- G. A. Edgar http://www.math.ohio-state.edu/~edgar/ === For a given group G does there always exist a group H such that G=Aut(H)? === > For a given group G does there always exist a group H such that G=Aut(H)?Not always. For example there is no group H such that Aut(H) is acyclic group of order 3.Alireza Abdollahi === > Not always. For example there is no group H such that Aut(H) is a> cyclic group of order 3.Can you prove this? === >> For a given group G does there always exist a group H such that G=Aut(H)?> > Not always. For example there is no group H such that Aut(H) is a> cyclic group of order 3.I guess if Aut(G) is of prime order pthen G/Z(G) is of order p or 1, and so G is abelian.It is easy to deal with _?ite_ abelian groups,but does the argument extend to in?ite abelian groups?If an in?ite abelian group has only a ?ite number of automorphismsis it necessarily ?itely-generated(in which case it would be easily dealt with).Im sure this is answered at length in Kaplanskys book.-- Timothy Murphy tel: +353-86-233 6090 === > >>> For a given group G does there always exist a group H such that>>> G=Aut(H)?>> >> Not always. For example there is no group H such that Aut(H) is a>> cyclic group of order 3.> > I guess if Aut(G) is of prime order p> then G/Z(G) is of order p or 1, and so G is abelian.> > It is easy to deal with _?ite_ abelian groups,> but does the argument extend to in?ite abelian groups?> If an in?ite abelian group has only a ?ite number of automorphisms> is it necessarily ?itely-generated> (in which case it would be easily dealt with).Most abelian groups have an obvious automorphismof order 2 :-)-- Robin Chapman, www.maths.ex.ac.uk/~rjc/rjc.html The League of Gentlemen === > > >> > suppose H is a normal subgroup in G and K is normal in H. Of course> > then K is a subgroup of G.> > But is K normal in G? Proof or counterexample!> >> > This problem occured to me some time ago, I dont have time to ?ure> > it out for myself these days so thanks for help!> > May be that Ive overlooked something.> > But, as K is normal in H it follows that> forall kin K ==> kin H> > The only thing we gotta check now is whether> g^{-1}kg in G> but as this holds for every h in H by hypothesis and -- by the statement> above -- every k lies H it follows that K is also normal in G.You have to check that g^{-1}kg is in K, not G. The statement is not necessarily true. Consider S_4, the set ofpermutations of four elements. Let G = A_4, the alternating group ofS_4 (i.e. the even permutations). Let H = {1, (12)(34), (13)(24),(14)(23)}, the Klein four-group. Then H is normal in S_4 and hence inA_4.Let K = {1, (12)(34)}. Then K is normal in H.However, K is not normal in A_4, since conjugating (12)(34) by (123)gives(13)(24) which is not in K.Rob === In Cantors Diagonal Argument reals are listed by their decimalrepresentations. However, if the digits in a decimal representationof a real are denoted d_1, d_2...d_n, then the set of numbers that comprise the subscripts of d are integers, and therefore are countably in?ite. Assuming the validity of uncountablty in?ite, a countably in?ite set of subscript numbers is not comprehensive; there must exist decimal places greater than the nth place where nis an integer. As the value of a given real is completed in acountably in?ite number of digits, any remaining digits must bezeros. If all reals have some point after which the remaining digitsare zeros, diagonalization no longer works. === What argument?> In Cantors Diagonal Argument reals are listed by their decimal> representations. However, if the digits in a decimal representation> of a real are denoted d_1, d_2...d_n, then the set of numbers that> comprise the subscripts of d are integers, and therefore are> countably in?ite.OK> Assuming the validity of uncountablty in?ite,?> a countably in?ite set of subscript numbers is not comprehensive;comprehensive?> there must exist decimal places greater than the nth place where n> is an integer.Hmmm. This sounds like the dreaded there are in?itely many integersdo there are in?ite integers argument.What do you mean here?That for each positive integer n there is a decimal place beyondthe n-th? (yes there is, for instance, the (n+1)-th).or, that there is a decimal place beyond the n-th for all positiveintegers n? (no, the decimal expansion is a function from N to {0,..,9})> As the value of a given real is completed in a> countably in?ite number of digits, any remaining digits must be> zeros.Aha, you did mean the second after all! But there are no remaining digits.> If all reals have some point after which the remaining digits> are zeros,They dont.> diagonalization no longer works.?-- Robin Chapman, www.maths.ex.ac.uk/~rjc/rjc.html The League of Gentlemen === > In Cantors Diagonal Argument reals are listed by their decimal> representations. However, if the digits in a decimal representation> of a real are denoted d_1, d_2...d_n, then the set of numbers that > comprise the subscripts of d are integers, and therefore are > countably in?ite. Assuming the validity of uncountablty in?ite, > a countably in?ite set of subscript numbers is not comprehensive; > there must exist decimal places greater than the nth place where n> is an integer. As the value of a given real is completed in a> countably in?ite number of digits, any remaining digits must be> zeros. If all reals have some point after which the remaining digits> are zeros, diagonalization no longer works.A decimal representation consists of a countable number of integers in the range 0..9. If you like you can think of a decimal representation as a function N->{0,1,2,...9} where N is the natural numbers.Its not clear what you mean when you say that a countably in?ite set of subscript numbers is not comprehensive. It is true that for any natural number n there are decimal places past n. But each decimal place is indexed by a natural number. === >In Cantors Diagonal Argument reals are listed by their decimal>representations. However, if the digits in a decimal representation>of a real are denoted d_1, d_2...d_n, then the set of numbers that >comprise the subscripts of d are integers, and therefore are >countably in?ite. Assuming the validity of uncountablty in?ite, >a countably in?ite set of subscript numbers is not comprehensive; >there must exist decimal places greater than the nth place where n>is an integer. Uh, right. Just like if the idea of in?ite sets is valid then everyset must be in?ite.Hmm.>As the value of a given real is completed in a>countably in?ite number of digits, any remaining digits must be>zeros. If all reals have some point after which the remaining digits>are zeros, diagonalization no longer works.************************David C. Ullrich === > In Cantors Diagonal Argument reals are listed by their decimal> representations. However, if the digits in a decimal representation> of a real are denoted d_1, d_2...d_n, then the set of numbers that > comprise the subscripts of d are integers, and therefore are > countably in?ite. Assuming the validity of uncountablty in?ite, > a countably in?ite set of subscript numbers is not comprehensive; > there must exist decimal places greater than the nth place where n> is an integer. Your last statement is incorrect. There are uncountably many realnumbers, but there also are uncountably many decimal digit sequences d_1,d_2, ..., where each such sequence is a countable collection of digits.Therefore, there are plenty of digit strings to go around, with no needfor uncountably-long strings to represent the real numbers.>As the value of a given real is completed in a> countably in?ite number of digits, any remaining digits must be> zeros. If all reals have some point after which the remaining digits> are zeros, diagonalization no longer works.Your premise doesnt hold. There are no remaining digits.-- Dave SeamanJudge Yohns mistakes revealed in Mumia Abu-Jamal ruling. === > In Cantors Diagonal Argument reals are listed by their decimal> representations. However, if the digits in a decimal representation> of a real are denoted d_1, d_2...d_n, then the set of numbers that > comprise the subscripts of d are integers, and therefore are > countably in?ite.I follow you up to here.> Assuming the validity of uncountablty in?ite, > a countably in?ite set of subscript numbers is not comprehensive; > there must exist decimal places greater than the nth place where n> is an integer. As the value of a given real is completed in a> countably in?ite number of digits, any remaining digits must be> zeros. ... a bit fuzzy but...>If all reals have some point after which the remaining digits> are zeros, diagonalization no longer works.This point does not exist. Moreover, there are countably in?itesets such as the rationals for which the above statement isnt trueeither. === > > >In Cantors Diagonal Argument reals are listed by their decimal> >representations. However, if the digits in a decimal representation> >of a real are denoted d_1, d_2...d_n, then the set of numbers that > >comprise the subscripts of d are integers, and therefore are > >countably in?ite. Assuming the validity of uncountablty in?ite, > >a countably in?ite set of subscript numbers is not comprehensive; > >there must exist decimal places greater than the nth place where n> >is an integer. > > Uh, right. Just like if the idea of in?ite sets is valid then every> set must be in?ite.> > Hmm.Well, a number such as 1.0 _could_ be expressed in a ?ite number ofplaces, but because of the validity of carrying out calculations pastthe zero (in?itely so), this number is thought to have an endlesstrail of zeros.I am asking: if uncountably in?ite is valid, then in the same way we require a (countably) in?ite number of decimal places even if the _value_ of a number can be expressed in a ?ite number of digits,why dont we require an uncountably in?ite number of decimal places even though any numbers _value_ will be expressed in a countably in?ite amount of places? (allow calculations to continue as the new size permits....)dg> >As the value of a given real is completed in a> >countably in?ite number of digits, any remaining digits must be> >zeros. If all reals have some point after which the remaining digits> >are zeros, diagonalization no longer works.> > ************************> > David C. Ullrich === I have answered the following in response the OTHER place where you posted the same comment. To post the same comment twice under two different subject headings, presumably in the hope that one of the postings will remain unanswered and thus appear to be unanswerable, is very bad form.Since I have already given an answer to the other identical posting that you made, I wont bother here, except to point out that I have made an extra remark at the end.>> >1. There exists two point masses moving towards each other.>> >2. At time T they collide at point P.>> >3. At time T two simultaneously paired opposite forces of equal magnitude occur>> >at point P.>> >> This is a contact force. On a side note, in Special Relativity, all >> forces are contact forces.>> >> >4. ________ >> >Fill in the blanks.>> >> Point mass 1 exerts a force on point mass 2, and point mass 2 exerts the >> paired force on point mass 1. The motion of point mass 1 is affected by >> the force exerted on it by point mass 2. Since the force exerted on point >> mass 2 by point mass 1 is not on point mass 1, then it has no effect on >> the motion of point mass 1. While you continue to consider that there is >> no effect of two paired contact forces on a system because they balance, >> then you are not doing Newtonian Mechanics, because you are making an >> assumption which is contradictory to Newtonian Mechanics (speci?ally,>> it is contradictory to Newtons Second Law of Motion).>You still have it all wrong.>POINT mass A has mass Ma.>POINT mass B has mass Mb.>At time t, a collision occurs at POINT p.>So at time t we observe mass A and mass B existing simultaneously at>point P. An equivalent observation would be that there exists a SINGLE>POINT>mass C with mass Ma+Mb existing at POINT P at time t.>Also at time t, we have the paired force as predicted by Newtons 3rd>law. Given that there is a single POINT mass at point p, then the>superposition principle applies and the paired forces cancel each>other out as predicted.>Do you see the problem yet?>> >> Newtons Three Laws of Motion:>> >> 1. If a body has no forces acting on it, then it either remains >> stationary or it moves uniformly.>Empirical evidence implies otherwise.>> 2. The time-derivative of the momentum of a body is equal to the >> sum of the forces which are exerted on the body.>Contact forces can never exist as they are always cancelled out at the>point of contact.>> 3. Forces are paired in such a manner that the forces in a pair >> are equal in magnitude and opposite in direction. The two forces>> in a pair are caused by the same mechanism. The same body >> experiences one of the forces and exerts the other, so that if>> one force in a pair is exerted on body A by body B, then the >> other force in the pair is exerted on body B by body A.>The problem with Newtons laws is that they do not de?e what a body>is and isnt. Furthermore, Newtons laws do not prohibit the existence>of POINT>masses and - as ive clearly shown - fails to predict their behaviour>(unless logical fallacies constitute strong evidence in academic>circles).As I pointed out when I responded to your other ideration = 7.5058959(93) x 10^87 rad/s^2> 139) thermal transfer constant = 6.2272531(21) x 10^88 kg/s^3-K > 140) current density constant = 7.2263839(39) x 10^92 A/m^2 > 141) gravitational density = 8.2089700(31) x 10^95 kg/m^3 > 142) energy density = 7.3778543(28) x 10^112 kg/m-s^ 2 > 143) radiance constant = 3.2280937(18) x 10^119 kg/s^3-sr> 144) irradiance constant = 2.2118250(84) x 10^121 kg/s^3