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[math-fun] Matthew Cook and his proof about Rule 110
by asimovd＠aol.com 22 Jan '03

22 Jan '03

Harold writes: << ... Cook's web page at CalTech has been "disappeared" (replaced by a "FORBIDDEN" notice, that is)... >> Can anyone explain how a mathematical theorem can be protected intellectual property? If there's one thing I thought I knew about intellectual property law, it was that *ideas* per se could not be protected. I've never heard of another situation where a theorem was considered proprietary. --Dan

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[math-fun] another ANKoS review
by Richard Schroeppel 21 Jan '03

21 Jan '03

[Thanks to Paul Chapman on the Life list for pointing this out.] Larry Gray's review of Wolfram's ANKoS is available online at http://www.ams.org/notices/200302/fea-gray.pdf This is a much more useful review than the previous AMS screed. It points to some of the useful ideas in the book, and doesn't get carried away with criticism of Wolfram. It also mentions a half dozen other reviews, with one sentence summaries. Rich rcs(a)cs.arizona.edu

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[math-fun] "Beal's Conjecture"
by Steve Gray 18 Jan '03

18 Jan '03

I thought this comjecture was relatively new, following Wiles' proof of FLT. But it is discussed, not in connection with Beal's name, in 1968. See "On Solutions of the Equation x^a + y^b = z^c" in Mathematics Magazine, 1968, p. 174, by Allan I. Liff, who presents some facts and conditions on its solution. I think the usual notation now is a^x + b^y = c^z. So far as I know, in all solutions found so far, one of x,y,or z is 2. Steve Gray

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[math-fun] Ideal polygons in the hyperbolic plane
by asimovd＠aol.com 17 Jan '03

17 Jan '03

In the Poincaré model, the hyperbolic plane H is viewed as an open unit disk D in the (ordinary) plane, with the geodesics being any arc of a circle that's perpendicular to the circular boundary bd(D). For any geodesic polygon in H, its area is A = [sum of its exterior angles] - 2 pi. One can also have ideal (geodesic) polygons, all of whose vertices lie on "the circle at infinity", i.e., bd(D). Since each exterior angle of such a polygon must be pi, its area is a function only of the number of sides N: A = (N-2) pi. Also, all the sides of an ideal polygon are of infinite length. QUESTION: When are two such ideal hyperbolic N-gons isometric (i.e., congruent in H) ? Note that the space of all such N-gons is N-dimensional (depending on the vertices on bd(D), whereas the group of isometries of H is the same as the group of conformal (or anti-conformal) automorphisms of D -- a 3-dimensional group. Hence there are N-3 dimensions of congruence classes of such ideal N-gons. >From this it's easy to see that all ideal triangles in H are congruent. Given the 4 vertices on bd(D) of each of two ideal squares in H, what's a concise algorithm to determine whether the two squares are congruent? --Dan

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Re: [math-fun] Copyright extension
by Dan Hoey 16 Jan '03

16 Jan '03

> Dan, > There seems to be a considerable interest in this topic. If it leaves you > cold, why not just delete the posts with subject line as above? > Regards, > Dan I'm sick and tired of mailing lists, newsgroups, and any other discussion forum turning into outlets for misinformation, posturing, poseuring, and vapid speculation on this topic. I did not subscribe to math-fun to listen to yet another copyright spew. It's not math, it's just something that EVERYONE has an opinion on, not just mathematicians. You don't think math-fun is the first place it's happened, do you? Copyright arguments EAT discussion groups. If you're so interested in getting misinformation on copyright, why aren't you reading misc.news.intellectual-property, or whatever it's called, on Usenet? You can get much greater quantities of opinions, with the same level of unreliability. And people there won't be asking "where's the math?" because those people are reading a newsgroup devoted to copyright opinionizing, not one they are reading for the math. Dan

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[math-fun] Re: Manners
by Dan Hoey 16 Jan '03

16 Jan '03

Joshua Singer <singer(a)stanford.edu> thinks my tone is uncalled for. Well, my tone expresses my discomfiture at having to endure this topic, argue against this topic, or both. Someone here might have the mistaken impression that I enjoy arguing against copyright discussions as much as I dislike the discussions themselves. No, I hate and abhor having to remind people that I'm here for the mathematics and not for extended discussions of other topics. I will not enter into any further remonstrations with people who misuse math-fun with discussions of what copyright law is and should be. If it continues beyond my tolerance, I will just unsubscribe. I like reading about math. I am not willing to subscribe to a copyright discussion group to do so. And if anyone tells me "just hit delete" again, I suggest you subscribe to sneh-lovers and see how many times you can hit delete before you've had enough. But I find it difficult to respect anyone's argument for the continuation of this discussion on math-fun. It's not like there aren't places where you can get copyright discussions, all copyright discussions all the time, and the people there are there for the copyright discussions. It's not like the you're going to find anyone posting to math-fun with any special expertise in the subject, or with any great potential for changing the status quo. In fact, the choice of math-fun as a venue for copyright discussion practically ensures that you are going to get half-baked opinions from people who don't know much about copyright, haven't thought through what they do know, and don't have a better outlet for their witless maunderings than gassing in e-mail. Forgive me if anyone who posted here actually _is_ a copyright lawyer, or legislator, or treaty negotiator, or pressure group runner. It certainly sounded like gas to me. And as for it being a popular topic, how about great sex? Everyone's interested in great sex. Let's have a discussion about our sexual experiences, fantasies, aspirations, and phobias, and by all means let's do it in the road on math-fun. And does anyone want to discuss the war on drugs on math-fun? I understand war is hell, but maybe it's more enjoyable on drugs, and I'm sure someone on math-fun has an opinion. How about Nu-Skin--I understand you can make more money with it than Amway, and if your friends turn against you, at least their skin is soft. What does math-fun think about international funds transfer, penis enlargement, collecting pop-tops for kidney transplants, the source of the phrase "rule of thumb", Joe Boxer, Joe Millionaire, Joe Camel, and Joe Pye Weed? Have you ever tried looking in the yellow pages, deleting ninety-eight or ninety-nine of every hundred words, and trying to make a theorem out of what is left? Would you like to try that with math-fun? I wouldn't. You know, I was just now working on the mathematics of Bingo, and here I have to leave for the weekend. Well, have a good one, and I'll see you all in some mathematical venue. Dan

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[math-fun] copyright topic - ground rules
by Richard Schroeppel 16 Jan '03

16 Jan '03

As list moderator, I've decided that copyright is somewhat on-topic since it affects (some of) our working conditions. However, I also agree with Dan Hoey that it isn't math. In order to keep our tempers about us, I'll impose the following rules for this instance of this topic: a) A limit of one more message per person. b) Time limit: 72 hours. Nothing after Sunday night (Jan 19). c) Trim replies: there's no need to repeat the whole discussion in each reply. d) Try to say something new. e) Try to sound pleasant. For those who want to read about the case, there's a web site (eldred.cc) set up by the plaintiffs that seems to have most of the legal filings, including arguments by the other side. For those who are sick of it, I think the Math-Fun web page has a "vacation" option to temporarily shut off the mail. Rich rcs(a)cs.arizona.edu

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Re: [math-fun] Copyright extension
by asimovd＠aol.com 16 Jan '03

16 Jan '03

Dan, There seems to be a considerable interest in this topic. If it leaves you cold, why not just delete the posts with subject line as above? Regards, Dan

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[math-fun] How big is a Gibibyte?
by Thane Plambeck 16 Jan '03

16 Jan '03

We engineers have long suffered from the confusion resulting from the regretable fact that powers of two are not also powers of ten. The IEEE has a draft standard "Standard Prefixes for Binary Multiples" http://www.ieee802.org/secmail/pdf00106.pdf that would clear up the nomenclature surrounding multiplication by 2^(10n). Unfortunately, I can't quite get myself to utter "kibibyte" without thinking of dog snacks. Here's an excerpt from the Draft standard, in the "Applications" section: * * * * Q: The formatted capacity of my hard drive seems smaller than what was ordered. Why? A: Your operating system assumes that 1 MB equals 1 048 576 bytes. Drive manufacturers consider 1 MB as equal to 1 000 000 bytes. Thus if the drive is advertised as 6.4 gigabytes (6 400 000 000 bytes) the operating system sees it as approximately 6.1 GB. [(6 400 000 000)/(1 048 576 000) = 6.1035...]. Thane Plambeck 650 321 4884 office 650 323 4928 fax http://www.qxmail.com/home.htm

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Re: [math-fun] Copyright extension
by Dan Hoey 16 Jan '03

16 Jan '03

Every person has an opinion about what copyright law is, and what it should be. Most of the opinions differ. Most of the former are erroneous, and most of the latter are wrong-headed. What makes any of us think anyone subscribed to math-fun to hear our erroneous, wrong-headed opinions on a subject we know so little about? Dan

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