Wikipedia talk:WikiProject Mathematics/Archive/2007/Dec

message: There is an interesting collection of photos of lots(!) of mathematicians at http://owpdb.mfo.de/. It seems that the institute is willing to grant WP the right to publish it here, see the discussion at the German Wikipedia http://de.wikipedia.org/wiki/Portal_Diskussion:Mathematik#Biographien_und_Fotos. Apparently the German Wikipedians don't want to take it under "Fair Use" license. I'm not that familiar with these license issues, but it is worth a look. Jakob.scholbach 14:47, 1 December 2007 (UTC)
replies: text: (Note: I haven't read the German discussion.) Fair use is not a license, but quite the opposite: it means that we decide to use an image claiming it is fair use under US law, whether the owner wants it or not. If what they mean is that they would give some sort of exclusive license to Wikipedia, I don't think that would be allowed by Wikipedia policies. It would have to be under a free license which allows everyone, not just Wikipedia, to use, modify, and distribute the images. --Itub 14:58, 1 December 2007 (UTC)
replies: text: I think the best thing we can do right now is wait for the results of the discussion on the German Wikipedia. The chances that the photos to which MFO actually has full rights (those with "Source: MFO") will be put under a sufficiently free licence to put them on Creative Commons seem to be by no means negligeable. Someone has contacted MFO already. If this fails, there might still be a chance to use some of the photos under fair use rules. The German Wikipedia does not accept fair use pictures (probably for legal reasons), but of course that doesn't restrict us. --Hans Adler 17:03, 1 December 2007 (UTC)
replies: text: I managed to justify fair use for a portion of one of the photos in this collection. Knowing the copyright holder is already helpful, as it is an important ingredient in the fair use rationale. Geometry guy 17:17, 1 December 2007 (UTC)

text: It isn't German law. German Wikipedia doesn't use nonfree images because they don't want to. We use them because there is no consensus on English Wikipedia to get rid of them. The Wikimedia foundation allows each project to decide individually. — Carl (CBM · talk) 02:28, 4 December 2007 (UTC)
thread_title:  photos of mathematicians 

message: The ICA page is somewhat of a mess, with the first definition on the page not being a true definition, and no examples or common uses. Does this page fall within the boundaries of the Mathematics project? I assumed so, so I'm posting a request here that it be the "article to be fixed of the day/week/month" so that a few people can check it out and fix it up. Thanks! -- eykanal talk 01:53, 3 December 2007 (UTC)
thread_title:  [[Independent Component Analysis]] page 

message: Look at List of inequalities.  There's a section titled "Pure mathematics" and another one titled "Probability theory".  "Pure mathematics" is in effect being used as a catch-all---a "none-of-the-above" category (except that in this case it's below rather than above).  Can it be organized into sections? Michael Hardy 16:22, 3 December 2007 (UTC)
replies: text: I'm working on that, in alphabetical chunks. If someone could review my work when I'm done, that would be great. -GTBacchus(talk) 18:14, 3 December 2007 (UTC)
replies: text: Ok, I sorted them all. There were some iffy cases (I'm not certain the various generalizations of the Arithmetic/Geometric mean inequality should be grouped together under "Analysis" as they are, and the inequalities under "Linear algebra" could probably be sorted differently), and I listed a couple of inequalities twice: Weyl's inequality, because there are two covered in the article; and Triangle inequality, which I put under "Geometry" and also under "Linear Algebra" (although I guess it's not true unless you're in a normed vector space, which is getting towards analysis). Corrections and improvements are more than welcome. -GTBacchus(talk) 18:49, 3 December 2007 (UTC)
thread_title:  Help organize the "list of inequalities" 

message: This is currently a redirect to . I think it should be deleted - it encourages 'flag planting' instead of actually rating articles. There's no need to tag talk pages since the List of mathematics articles already lists all the math articles. — Carl (CBM · talk) 15:59, 4 December 2007 (UTC)
replies: text: I agree. I guess it was created (recently) for consistency with other WikiProjects. Instead they should be encouraged to adopt the "rating" approach :-) Geometry guy 21:16, 4 December 2007 (UTC)
thread_title:  [[Template:WikiProject Mathematics]] 

message: User:Oleg Alexandrov suggested I came here for insightful comments on the constant article I'm working on. I've basically rewritten most of the article, do you think I'm on the right track? Randomblue (talk) 21:00, 6 December 2007 (UTC)
thread_title:  Constant article 

message: Would someone be so kind and have a look at the "wrong proof". Thanks --Meisterkoch (talk) 16:21, 8 December 2007 (UTC)
replies: text: The portion of the proof which "derives" the Euler-Wallis formula for \sin(x) is incorrect, but the formula itself is right.  It is valid to insert \pi/2 into that formula and equate both sides, and since the infinite product converges it is also valid to take the inverse of both sides and equate them.  So the proof is "right", but presented in a rather uninformed, naive way.  Also, Wallis' formula has an elementary proof using integration by parts.  I will correct what is there but I do not advocate adding the second proof; it is not of encyclopedic value and I'm not sure about the one that's there either.  It at least has the virtue of being entertaining. Ryan Reich (talk) 16:45, 8 December 2007 (UTC)
replies: text:  ;-). Thanks --Meisterkoch (talk) 16:48, 8 December 2007 (UTC)
thread_title:  Wallis product 

message: See talk:Lists of mathematics topics#This article doesn't pass WP:VER and Wikipedia:Featured list removal candidates/Lists of mathematics topics.  The Transhumanist    22:28, 10 December 2007 (UTC)
thread_title:  [[Lists of mathematics topics]] issues 

message: I removed Homotopy groups of spheres from Wikipedia:WikiProject_Mathematics/A-class_rating today; it isn't A-class yet but the comments show it is getting close. Meanwhile Pi is a new candidate, nominated by Disavian. This is obviously an extremely important article for a general encyclopedia. Give it a read to see how far it has come. 
Although it's a relatively low-volume process, the A-class rating system gives detailed peer review about mathematics articles by editors who are familiar with the topic, without the hassle of the featured article process. I hope more editors will take advantage of it. — Carl (CBM · talk) 16:46, 11 December 2007 (UTC)
thread_title:  A-class rating 

message: With help from Hans Adler, I have been working on a major expansion of Mathematical logic. If you have interest or expertise in the area, and the time to read through it, I would appreciate any suggestions you have to fill out the coverage or improve the exposition. — Carl (CBM · talk) 20:32, 11 December 2007 (UTC)
thread_title:  [[Mathematical logic]] 

message: Can anyone confirm what SilvermanJ. H. Silverman, "Wieferich's criterion and the abc-conjecture", Journal of Number Theory, 30:2 (1988) 226-237 actually proved from the abc Conjecture?  The consensus seems to be:
* for any positive integer a > 1, there exist infinitely many primes p such that p² does not divide ap − 1 − 1. 
but WAREL quotes
* there exist infinitely many primes p such that p² does not divide 2p − 1 − 1. 
(In either case, we need to revert that idiotic superscript 2 character to 2.  Is it possible for an AWB substitution to select those?) — Arthur Rubin |  (talk) 18:02, 12 December 2007 (UTC)
replies: text: Well, block him first, and we can discuss if he is right later. :) Seriously, it is highly unlikely he is right, and he has shown to be a very poor expert in mathematics (one of his recent claim was that any integral domain was a division ring). I suggest that when in doubt his edits be reverted, just to keep on the safe side. Oleg Alexandrov (talk) 05:43, 13 December 2007 (UTC)
replies: text: What a persistent edit warrior! Surely there is a pretty solid case for an extended or indefinite block at this point, no? —Cronholm144 06:02, 13 December 2007 (UTC)
replies: text: His actual accounts (except WAREL) have been indefblocked as sockpuppets.  (I think the explanation for some of the sockpuppets is that he forgot the password to WAREL.  After all, it may be an English word, and it's clear he doesn't understand English.)   At least one admin believes this IP to be in SoftBank's dynamic pool, even though all edits from the IP have been in WAREL's style, so it can't be indefblocked.  WHOIS says "status:       ALLOCATED PORTABLE".  I suppose we could ask SoftBank whether it's static or dynamic by filing an abuse report....  — Arthur Rubin |  (talk) 18:00, 13 December 2007 (UTC)

text: Oleg was the last to block WAREL, back in '06.  — Arthur Rubin |  (talk) 18:03, 13 December 2007 (UTC)
replies: text: Ick. Is WAREL really annoying enough to go through the trouble of filing such a report? Or is the policy of revert->block->ignore enough? —Cronholm144 18:12, 13 December 2007 (UTC)
thread_title:  [[Wieferich prime]] and [[User:WAREL|WAREL]] 

message: Some users are talking about starting a Wiki Project for mathematical biology, e.g. in user space this  tentative project page. I added math to the list of related projects. On account of my interest in convergence phenomena in self-adapting genetic algorithms, I'm a big believer that we can suck up their wisdom the way we have leeched physicists for centuries :-) Pete St.John (talk) 17:35, 13 December 2007 (UTC)
thread_title:  Mathematical & Computational Biology 

message: After being in unsatisfactory form as a subpage of a user page for a long time, the list of triangle topics is now an article, no longer a red link within the lists of mathematics topics.  Of course it could still use improvement, so work on it! Michael Hardy (talk) 01:30, 14 December 2007 (UTC)
replies: text: I merged the page history from User:DavidCBryant/List of triangle topics  into List of triangle topics. The page history is not that important, but it is nice to have. Oleg Alexandrov (talk) 06:25, 14 December 2007 (UTC)
thread_title:  List of triangle topics 

message: If you weren't having enough AfD fun already, I happened to notice that the page Natural mathematics seems a little, well, confused.  As elaborated at further length here, there's reason to suspect it's a work of, er, fractured ceramics.  Somebody more familiar than I with the philosophy of mathematics might be better able to tell if there's content there worth salvaging.
Cheers, Anville (talk) 19:33, 16 December 2007 (UTC)
replies: text: Salix Alba has taken it to AfD. I was about to prod it with notification to the original author and Gregbard, who tagged the article talk page with the WikiProject Philosophy banner. The question is, are there reliable secondary sources that support notability? Geometry guy 19:57, 16 December 2007 (UTC)
replies: text:  Notability issues may be confused by other topics being discussed under the same name; I believe there's a concept in children's mathematics education which goes by the same name ( ).  Anville (talk) 21:19, 16 December 2007 (UTC)
thread_title:  "[[Natural mathematics]]" 

message: A requested move Boolean logic in computer science → Boolean logic  is being discussed here.  --Lambiam 22:50, 17 December 2007 (UTC)
thread_title:  Requested move Boolean logic in computer science → Boolean logic 

message: A related issue that comes up regularly concerns proofs, often elementary inductions, added to articles without crediting a source for that proof. I'm no longer convinced that this is a good idea, but here's an example of one I added myself, over a year ago: Fáry's theorem. If an article contains a proof, is it necessary that the proof adhere closely to one of the published proofs of the same result and be credited to a reliable source, or do we view proofs of this type as self-verifying? Obviously if a particularly clever proof can be attributed to someone, it should be, as a matter of good scholarship, but I am thinking here more about whether an uncredited proof should be viewed as original research and disallowed as such.
I note that Totient function/Proofs survived AfD without this issue really being directly addressed; it has since been sprinkled with fact tags, but those are for the individual assertions within its proofs, not for the provenance of the proof as a whole. —David Eppstein (talk) 19:55, 16 December 2007 (UTC)
replies: text: I think the details of a proof are self-verifying. However, the proof should have an overall provenance. What is needed in this article is not a string of citations, but a couple of references to good number theory textbooks which contain these results. Geometry guy 20:08, 16 December 2007 (UTC)
replies: text: In theory a proof could be self-verifying, but in practice how many of the proof of these articles have been checked? Could there be typo errors or even invalid assumptions. A reference adds to the verifiability of the article.
I've had a look though some of the proof articles:
*Addition of natural numbers/Proofs - Proof using sucessor operations, no references
*Approximation theory/Proofs - Hand wavy proof, by reference to a graph, no references
*Proof of Bertrand's postulate - A proof appeared in Proofs from THE BOOK so high on the notability states.
*Cardioid/Proofs - Fairly standard algebra, not particularly interesting as a proof. Unreferenced. 
*Chebyshev polynomials/Proofs - A little bit of calculus. Unreferenced.
*Christoffel symbols/Proofs - Poor on context, hard to tell whats being proved as no theorem statements. unreferenced.
--Salix alba (talk) 20:54, 16 December 2007 (UTC)

text: I think the original research policy is very clear on this. Original proofs are not allowed. Otherwise we will have no protection against a crank who wants to post a "self-verifying proof" of the continuum hypothesis, for example.  Attempting to argue with such a person on the grounds of correctness will only lead to trouble. Perturbationist (talk) 03:07, 19 December 2007 (UTC)
replies: text: Proofs of new results are no good, for the reason you just gave. On the other hand, a new exposition of a well-know result using a standard technique is probably fine. — Carl (CBM · talk) 03:11, 19 December 2007 (UTC)
thread_title: Related issue: Are original proofs acceptable?

message: Talk:Carl Hewitt has been protected, to supress this discussion. Is that appropriate?  Comments? (I guess we need to comment here, since again, that talk page is protected). Oleg Alexandrov (talk) 05:08, 18 December 2007 (UTC)
replies: text: I've started a discussion (in very unspecific terms) at Wikipedia talk:Biographies of living persons, which I think may be a more appropriate place for this. —David Eppstein (talk) 05:35, 18 December 2007 (UTC)
replies: text: Update:  has unprotected it, with conditions. See Talk:Carl Hewitt#Suggestion. JRSpriggs (talk) 01:38, 19 December 2007 (UTC)
thread_title:  Page protection of [[Talk:Carl Hewitt]] 

message: May I request your attention for the following burning question: should the verifier-based definition of NP-complete in the section Formal definitions for P and NP of P = NP problem use the definite article (the verifier) or the indefinite article (a verifier)? The discussion has stalled. See Talk:P = NP problem#Request for comments: "the" verifier or "a" verifier?.  --Lambiam 08:39, 22 December 2007 (UTC)
thread_title:  Request for comments: "the" verifier or "a" verifier? 

message: I added canonical representative to Wikipedia:Requested_articles/mathematics a few days ago, and Jitse's bot has updated Wikipedia:WikiProject Mathematics/Current activity since then, but my request doesn't appear on that page.  Why is that?  -- Dominus (talk) 03:02, 24 December 2007 (UTC)
replies: text: It must have been a while back, the 4th Dec version had canonical representative and the Bot only adds requested articles from the last week or so. --Salix alba (talk) 10:26, 24 December 2007 (UTC)
replies: text: My brain says I added it around 20 December, but the edit history says I didn't.  Freaky.  -- Dominus (talk) 20:59, 24 December 2007 (UTC)
thread_title:  [[Wikipedia:WikiProject Mathematics/Current activity]] 

message: I have nominated one of us, Salix alba, for adminstrator position. If you know Salix alba and would like to comment in the discussion, you can do so at Wikipedia:Requests for adminship/Salix alba. Oleg Alexandrov (talk) 16:35, 17 December 2007 (UTC)
replies: text: Salix alba's RFA ended successfully with 80 supporting opinions and no opposing opinions, which is a strong expression of confidence. — Carl (CBM · talk) 13:08, 25 December 2007 (UTC)
thread_title:  Salix alba for admin 

message: I think, there is an invalid statement in the middle of the section Examples in the article permutation group. There is stated: G forms a group, since aa = bb = e, ba = ab, and baba = e. So (G,M) forms a permutation group. However nowhere is mentioned associativity of permutations, although there is ab = ba, which refers to commutative group. I'm only starting with group theory, so it might be correct, only I can't see how these properties imply associativity. Even if it is true, I think, it is a bit misleading. Please, somebody have a look at it. Thanks. --Tomaxer (talk) 00:03, 28 December 2007 (UTC)
replies: text: Associativity is automatic, since G is contained in the permutation group on 4 letters, and composition of functions is always associative. Thus we just need to check that G contains the identity and is closed under composition and inverses. Algebraist 01:18, 28 December 2007 (UTC)
replies: text: There is an issue - neither the permutation group article nor the symmetric group article seems to state explicitly that composition of bijections is associative. Does anyone want to take a stab at explaining it? Which page should it go on (both?) — Carl (CBM · talk) 01:28, 28 December 2007 (UTC)
replies: text: It's mentioned at associativity#examples, at least. Algebraist 02:08, 28 December 2007 (UTC)

text: Function composition also mentions the more general fact that composition of functions is associative. —David Eppstein (talk) 02:13, 28 December 2007 (UTC)

text: I've added a section "Product and inverse of permutations" to the article on permutations. Please review.  --Lambiam 12:13, 28 December 2007 (UTC)
replies: text: That's a natural place for it. I also added very brief paragraphs to the group articles. This is the sort of fact that writers are likely to take for granted but readers (especially if their prof has impressed the need to verify all the group axioms)  may wonder about. — Carl (CBM · talk) 20:21, 28 December 2007 (UTC)
thread_title:  Example in the article Permutation group 

message: As we have tried, and tried to improve mathematics education for elementary and secondary students, it is obvious that a simpler, humbler, more beautiful definition of mathematics is urgently needed.  I am personally tired of trying to fit some of the narrow focused, often distracting, and often arrogant definitions I find at hand.  Yes, we deal with forms. patterns, a language, and can discuss about structures being "pure" or "applied", but I am sure there are simpler ways of explaining the nature and high value of mathematics to our frustrated children and  math-phobic adults.  There is a great disservice being done today by much of the K-12 curriculum being defined by people who do not seem to understand the yearnings of common people to see the simpler meaning of things, precision, accuracy, reliable predictability, cost-benefit, and safety, among others.  Mathematics, I believe is not "the language of god", as we sometimes want to define it, perhaps to give ourselves some self-improtance (talking like god?), but a useful tool that, pure or applied, is intended to be part of all our activities, sciences, arts, and religions, and make our lives easier, happier. 
I KNOW there are simpler definitions, but sometimes it feels like it will take another 100 years, before we can get off our high math horse - Last year I tried to suggest a new, more pragmatic addition to try to help on this, but that was removed (!!!) by Wikipedia. So far for contributive definitions.[[User:68.7.11.138 (talk) 00:51, 31 December 2007 (UTC)
replies: text: What was your contribution?  As your IP address hasn't made prior contributions, and User:Felipe Razo doesn't seem to exist, I don't know what you're talking about.  — Arthur Rubin |  (talk) 00:55, 31 December 2007 (UTC)

text: It should also be pointed out that there are always simple, wrong definitions of mathematics and mathematical concepts.  "Make everything as simple as possible, but not simpler."  — Arthur Rubin |  (talk) 00:59, 31 December 2007 (UTC)

text: OK, hard to chase this page editing tail format.  I guess you are right, there are wrong, and oversimplified definitions, and that is NOT beautiful, you should know.  For some reason I feel that it is still hard to move out of the box on this issue, and I should not be wasting your, or my time anymore.  I will continue to do what is right and productive with my students.  Thank you for your attention. 68.7.11.138 (talk) 01:18, 31 December 2007 (UTC)
thread_title:  A simpler, more beautiful definition of mathematics?