Wikipedia talk:WikiProject Mathematics/Archive/2008/Sep

Groups FAC

Since it seems to be standard to gather some feedback on FAC's prior to actually nominating: I'm about to propose group (mathematics) for featured article candidacy (next week or so). It has obtained GA status and has also had a peer review since. Whoever is interested in this, have a look at the article. Jakob.scholbach (talk) 12:40, 25 August 2008 (UTC)

After a very quick scan, it looks good. However, I did not notice any mention of free groups or free abelian groups. Are they mentioned? JRSpriggs (talk) 12:56, 28 August 2008 (UTC)

The only use of the word 'free' in the article is in the following:

Quotient and subgroups together form a way of describing every group by its presentation: any group is the quotient of the free group over the generators of the group, quotiented by the subgroup of relations.

Algebraist 13:06, 28 August 2008 (UTC)

Just until a few days ago, we did have a slightly more detailed mentioning of freeness. However, due to total length considerations, I removed the paragraph containing this piece of information. Regrettably or not, there are many things which have a reasonable right to show up there, some choices have to be made. Jakob.scholbach (talk) 12:51, 30 August 2008 (UTC)

Proposed deletion of Paul Zimmermann

Just to inform you, I've tagged Paul Zimmermann for proposed deletion. Please consider improving the article. I don't no nothing about mathematics or people who do this stuff ;-) But this article fails Wikipedia:Notability (academics) and Wikipedia:Verifiability, because I can't see any conditions met (meeted ... hm what's the word) fulfilled and there is no secondary source. Greetings (and plz excuse my bad English, I'm not a native speaker and don't want to sound rude.) Sebastian scha. (talk) 02:19, 30 August 2008 (UTC)

Integration using complex analysis

Integration using complex analysis seems misleadingly titled, since that term would usually be taken to mean something like the residue calculus. What should it be moved to? Should this title be redirected to a different already-existing article? Michael Hardy (talk) 15:17, 30 August 2008 (UTC)

This article was split from Integration with other techniques, which had already been prodded. I guess this means that whoever did the splitting contested the prod. Anyway, now there are three articles to delete instead of just one. *sigh* siℓℓy rabbit (talk) 15:28, 30 August 2008 (UTC)

I have replaced Integration using complex analysis with a redirect to Residue calculus. siℓℓy rabbit (talk) 15:32, 30 August 2008 (UTC)

I'm not sure that Integration using parametric derivatives needs to get deleted. Michael Hardy (talk) 16:51, 30 August 2008 (UTC)

I think that what the article Integration using complex analysis was referring to was Real integration which happens to involve i which is just a constant. I don't think the intention was to refer to contour integration at all. I think this should be reverted and clarification added by carrying the calculation out to the end:

=Re (1/(1+i)) * exp((1+i)*x)

=Re ( 1/2 + i*1/2 ) * exp(x) * (cos (x) +i*sin(x))

=Re 1/2*exp(x)*cos(x)+1/2*i*exp(x)*sin(x)-1/2*i*exp(x)*cos(x)+1/2*exp(x)*sin(x)

=1/2 exp(x)*cos(x) + 1/2 exp(x)*sin(x)

I don't know if there is a commonly used name for this technique, but something like Integrating by writing trig functions as exponentials. Delaszk (talk) 22:00, 30 August 2008 (UTC)

Certainly integration using complex analysis is not the right name for it. There's no use of complex analysis, even though complex numbers turn up.

I'm not convinced that this technique merits its own article. Is there an example of a function which is substantially easier to integrate this way than by other techniques (like integration by parts)? Ozob (talk) 00:04, 31 August 2008 (UTC)

I don't think it fits in any of the other articles on integration techniqes. I've moved it to Integrating trigonometric products as complex exponentials. Delaszk (talk) 08:14, 31 August 2008 (UTC)

Uniform names for articles on numbers in different languages

The following articles do not cover any pure numeral system where the symbols and notations are clearly defined, instead they cover how numbers are used in the respective languages. I have proposed all of them be moved. Please discuss HERE.

• Names of numbers in English → Numbers in English
• Chinese numerals → Numbers in Chinese
• Japanese numerals → Numbers in Japanese
• Korean numerals → Numbers in Korean
• Welsh numerals → Numbers in Welsh
• Proto-Indo-European numerals → Numbers in Proto-Indo-European

Thank you. --Voidvector (talk) 07:45, 31 August 2008 (UTC)

Hundred-dollar, Hundred-digit Challenge problems

Hundred-dollar, Hundred-digit Challenge problems is an orphan, linked to only from the list of mathematics articles. It seems like something that deserves more attention, but just which articles should link to it isn't something for which I have any quick answers. Michael Hardy (talk) 14:08, 31 August 2008 (UTC)

Groups for FAC

The article is up for FAC now. Please opine here. Jakob.scholbach (talk) 12:28, 1 September 2008 (UTC)

Problem editor at Affine curvature

User:Dojarca persists in inserting a formula into the article Affine curvature which he/she claims to be an accurate representation of one found in an obscure (nonexistent?) source. In addition to correcting the formula and providing a source, I have explained why the formula was incorrect in about five or six different ways (of increasing level of sophistication) on the talk page of the article. An edit war is brewing... siℓℓy rabbit (talk) 13:44, 1 September 2008 (UTC)

The case is somewhat different. Silly rabbit peristently deletes from this article a formula taken from a mathenatic encyclopedia and inserts his own derived variant, claiming it is more correct.--Dojarca (talk) 13:47, 1 September 2008 (UTC)

It isn't a "variant", it is a "completely different formula". The formula you persistently restore is totally and completely wrong for umpteen different reasons. It's baffling to me why you continue to insist that it is correct. siℓℓy rabbit (talk) 13:51, 1 September 2008 (UTC)

Dojarca's version cannot possibly be correct, since it is always positive and the first paragraph of the article discusses negative curvatures. Either Dojarca's version is just wrong, or there are differing definitions of affine curvature. Either way, having an inconsistent article is never right. --Tango (talk) 22:04, 1 September 2008 (UTC)

To Tango: As of 19:46, 1 September 2008, Dojarca agreed with Silly rabbit that the dispute had been resolved and removed the disputed tag from the article. After two minor errors were discovered and corrected in Dojarca's formula, it was accepted as correct and equivalent to Silly rabbits' formula. The article now incorporates both as follows.

${\begin{aligned}k(t)&={\frac {x''y'''-x'''y''}{(x'y''-x''y')^{5/3}}}-{\frac {1}{2}}\left[{\frac {1}{(x'y''-x''y')^{2/3}}}\right]''\\&={\frac {4(x''y'''-x'''y'')+(x'y''''-x''''y')}{3(x'y''-x''y')^{5/3}}}-{\frac {5}{9}}{\frac {(x'y'''-x'''y')^{2}}{(x'y''-x''y')^{8/3}}}\end{aligned}}$

The end. JRSpriggs (talk) 02:17, 2 September 2008 (UTC)

Gang Tian or Tian Gang

Gang Tian, Tian Gang. It's weird to read a section like this without being able to click on a link to the article. Michael Hardy (talk) 23:29, 2 September 2008 (UTC)

As someone who at least has a passing acquaintence with the man, I believe the article should be "Gang Tian" instead of "Tian Gang". This is also how his name appears in all of his English-language publications. However, the page was recently moved by User:Ramtears with the edit summary: moved Gang Tian to Tian Gang: Chinese name convention. Does anyone else have a strong opinion about this? My own feeling is that if all reliable English sources use Gang Tian, then so should the Wikipedia entry. Anyway, if there is consensus, I suggest that an admin should undo this move. siℓℓy rabbit (talk) 21:14, 31 August 2008 (UTC)

I agree. Chinese mathematicians working in the US adopt American naming conventions, and that's how they're known here. RayAYang (talk) 21:41, 31 August 2008 (UTC)

I have undone the move (anyone could have done it, it wasn't blocked). Kusma (talk) 11:48, 1 September 2008 (UTC)

And it has been moved back. Can somebody help me explain our conventions to the guy who moved it again? Kusma (talk) 12:52, 2 September 2008 (UTC)

His MIT web page says "Gang Tian", and I remember that when I was at MIT, that's how his name appeared on his office door. Michael Hardy (talk) 23:33, 2 September 2008 (UTC)

The issue is there are two style guides. WP:NAME says "While the article title should generally be the name by which the subject is most commonly known, the subject's full name should be given in the lead paragraph, if known." And WP:NC-CHINA says "The encyclopedia should reference the name more familiar to most English readers." It also says that "There is an exemption for people whose Chinese name is familiar but with English ordering (for example, Wen Ho Lee). In this case, the primary entry should be under the English ordering with a redirect from the Chinese ordering." So I recommend a short discussion on the talk page, to establish which name is commonly used in English. — Carl (CBM · talk) 23:57, 2 September 2008 (UTC)

calculus and non-standard calculus

I am a standard mathematician, in the sense that I was not formally trained either in Robinson's hyperreals or any other variety of pseudo or surreals. At the same time, I find the infinitesimal approach to be a helpful educational tool (aside from the issue of its merit as a research tool). I have correspondingly added some links in the standard calculus pages such as uniform continuity to the non-standard page explaining helpful and simpler approaches to some of these standard results. I hope to forestall edit wars and reverts by opening the discussion of the issue here, it being understood that everyone will abide by the results of such a discussion. Katzmik (talk) 11:43, 1 September 2008 (UTC)

I agree that non-standard analysis is an interesting area - it certainly explains why an informal argument using infinitesimals so often produces the same answer as a rigorous epsilon-delta limits argument. However, I am not so sure about the claims that proofs in non-standard calculus are simpler or clearer than standard proofs. They are only simpler if you start from the base-camp of the fundamentals of non-standard analysis - and it seems to me that it takes quite a high level of mathematical maturity to reach that base camp on foot. Of course, the teacher can "helicopter in" their students by saying "trust me, we can make all this rigorous if we have to" - but then you are essentially falling back on an informal argument, and not demonstrating a rigorous proof. Gandalf61 (talk) 12:31, 1 September 2008 (UTC)

As your message is a little bit vague concerning the question of rigor, I would like to clarify that non-standard analysis is completely rigorous and does not rely on any axioms beyond standard ZFC that standard mathematics is built upon. Katzmik (talk) 12:48, 1 September 2008 (UTC)

Yes, I understand that - I didn't mean to imply that non-standard analysis is not rigorous. I was trying to say that by the time you expand on the rigorous foundations that underly a non-standard analysis proof of the intermediate value theorem, for example, then you no longer have the nice simple two-line proof that you thought you had. In other words, if you start from something close to first principles, I doubt that non-standard proofs are generally any simpler, shorter or easier to grasp than standard proofs. You asked for a discussion, so that is my contribution - let's see what others thinks. Gandalf61 (talk) 13:00, 1 September 2008 (UTC)

It is true that non-standard analysis requires foundational work. On the other hand, so does the construction of the real numbers. Most calculus courses nowadays teach neither equivalence classes of Cauchy sequences, nor Dedekind cuts. The question is, how far back to the axioms do you want to go when you teach today's undergraduates. At any rate, the fact that both Newton and Leibniz DID use infinitesimals says something in their favor when it comes to assessing their usefulness in actually explaining what goes on in these theorems. Katzmik (talk) 13:45, 1 September 2008 (UTC)

The sense in which infinitesimals are used in the work of Newton and Leibniz is of course completely different from the way they are used in the work of Robinson and other nonstandard analysts. To obscure this difference is to do a disservice to Robinson's work, which has always been received by the mathematical community as rigorous and correct, whereas infinitesimals were viewed with great uneasiness for about 200 years until the important work of Cauchy and Weierstrass which did away with them.

The pedagogical value of infinitesimals is an interesting question -- probably it is too rich to be satisfactorily dealt with here. One should begin, I think, with making the context clear: separate discussions are probably required for (i) standard freshman calculus, (ii) honors calculus (e.g. from Spivak's book), (iii) undergraduate analysis, (iv) graduate level and beyond. At the level (i), my opinion is that the vast majority of students will not understand -- and will not want to understand -- any deeply theoretical discussion of limits, continuity, etc. If as an instructor you nevertheless want to sneak in at least a little taste of this theoretical material (as I usually do), you have a real pedagogical challenge. One of the prerequisites for success here is to yourself have a very firm and flexible (so to speak) understanding of the theory, so that you can spin it around in any direction and present small snapshots of it in a coherent and palatable way. This is not easy to do, and I have grown to believe that most authors of calculus textbooks are not good enough at this -- when they decide they want to cover "theory", they pedantically rehash canned definitions from the textbooks one level up (which they never explicitly reference, for some reason). For this reason I would not at the present time even consider using a "nonstandard calculus textbook" because my own understanding of nonstandard analysis is not deep enough, and I think the average instructor (even one who is a research mathematician) would feel the same way.

On the other hand, some physical intuition and language is certainly appropriate in places: I have no qualms about writing down a formula for, e.g. the "differential work" and then putting an integral sign in front of it to get the work. I just don't say "infinitesimal", and I try to lightly remind the students with the connection to Riemann sums (although I would be perfectly happy to replace this with the corresponding allusion to some simpler but equivalent integration theory).

Concerning the passage: "Consider for instance the function f(x) = 1/x with domain the positive real numbers. This function is continuous, but not uniformly continuous, since as x approaches 0, the changes in f(x) grow beyond any bound. A clearer explanation of this phenomenon may be found at non-standard calculus." Indeed a clearer explanation is warranted, but can certainly be provided in the context of the epsilon-delta definition. Any or all of the following would be nice: (i) Directly compute |f(x+delta)-f(x)| and observe that, for any fixed delta, this quantity tends to infinity as x tends to zero. (ii) Discuss instead the example f(x) = x^2 on the real line (also done by a similar, but even simpler, direct computation) and/or restrict to f(x) = 1/x on (0,1] and note that that the domain is bounded but the image is unbounded. I will try to make some of these changes.

My feeling is that best would be to include material and/or links on nonstandard calculus/analysis in separate sections. It could be a nice advertisement for the nonstandard theory to give some quick proofs of standard theorems (modulo the machinery of nonstandard analysis, of course). Plclark (talk) 14:48, 1 September 2008 (UTC)

To respond to your point about Newton and Leibniz, I would like to mention that there are at least two reasons to carefully distinguish between their infinitesimals and Robinson's. The first is that he is rigorous. The second is the existence of alternative theories of infinitesimals. Other than that, it can be, and it has been, said that Robinson put Leibniz's infinitesimals on a rigorous footing. I am not sure what you are objecting to exactly in such a formulation. Katzmik (talk) 15:00, 1 September 2008 (UTC)

I don't find anything objectionable in that formulation. My points are: first, that Newton and Leibniz didn't have a "theory" of infinitesimals in the modern mathematical sense: they had a kind of algorithmic yoga that made both their contemporaries and descendants uncomfortable. Second, they didn't prefer differentials to epsilons and deltas, since they didn't have the epsilon-delta definition. Plclark (talk) 15:22, 1 September 2008 (UTC)

At level (i) (undergraduate calculus), I would like to mention that I have personally taught calculus based on Keisler's wonderful book, to the satisfaction of both the students and the TA (who had, of course, to re-learn everything he learned in college). Katzmik (talk) 15:03, 1 September 2008 (UTC)

From a google search I gather you mean http://www.math.wisc.edu/~keisler/calc.html. I am not familiar with this book. Could you say something about how a course based on this book would be different -- for the students -- than a more traditional course? I notice that Keisler's preface claims that infinitesimals are more easily understood than limits -- did your students find that to be the case? How much of a freshman calculus class depends upon what's inside the black box named "limit" anyway? (These are not rhetorical questions; I'm interested to hear your response.) Plclark (talk) 15:22, 1 September 2008 (UTC)

A course based on Keisler's book would be very different. For example, a considerable amount of time is spent in a standard course on various manipulations involving limits. A special term "an indeterminate expression" is introduced to describe things like ${\tfrac {0}{0}}$. Various theorems are proved about manipulations of limits, sums, products, what happens when numerator goes to zero, what happens when it goes to infinity. In Keisler's approach this is translated into a set of rules about manipulating hypperreals. For example, an infinitesimal divided by a non-zero standard real, is necessarily infinitesimal. An infinite number divided by a finite number is infinite, etc. Once the student has mastered these rules, one can proceed to derivatives, continuity, etc. Whether or not one gets into epsilon-delta proofs in the standard course, the hyperreal approach is more convenient since one has it his disposal a collection of ideal objects that simplify all definitions, statements, and proofs. To give an analogy, consider minimal surface theory. Minimal surfaces have certain properties not possessed by arbitrary surfaces. If one did not assume the existence of minimal surfaces and had to satisfy himself with statements about surfaces that are only approximately minimal in a suitable sense, obviously this would complicate the statements about them. Katzmik (talk) 12:06, 2 September 2008 (UTC)

Okay, here's a question that occurs to me. The standard proof of the intermediate value theorem depends in an explicit way on the completeness of the reals, so it is not surprising that the theorem is not true for functions over a non-complete field such as the rationals. But one of your brighter students argues as follows: let's construct "hyperrational numbers" in an analogous way to the construction of hyperreals; then we apply the non-standard calculus proof of the intermediate value theorem to functions over these "hyperrational" numbers; since the intermediate value theorem is true for functions over "hyperrationals" then it must also be true for functions over the rationals. Where has your student gone wrong ? The non-standard proof of the intermediate value theorem does not seem to depend explicitly on completeness - so presumably their mistake is either in the assumption that "hyperrationals" can be constructed with analogous properties to hyperreals, or in the assumption that properties of functions over "hyperrationals" transfer back to properties of functions over rationals. How do you explain their mistake in terms that they can understand ? Gandalf61 (talk) 13:18, 2 September 2008 (UTC)

Great question, hope I have the right answer (I mentioned already that I have no professional training in non-standard analysis, although I seem to have been able to defend myself successfully at the talk page of non-standard calculus recently). At any rate, π can be made to look like a hyperrational by taking the n-th continued fraction with n hyperinteger. We see that the standard part of a hyperrational may be irrational. In fact, perhaps the shortest construction of the reals out of the rationals may be via hyperrationals. Katzmik (talk) 13:27, 2 September 2008 (UTC)

Indeed. Another way of looking at this is that if you apply the ultrapower construction to the rationals, then any sequence converging to an irrational will correspond to a finite hyperrational that is a non-infinitesimal distance from any rational; in other words a finite hyperrational without a rational standard part. Algebraist 13:49, 2 September 2008 (UTC)

Okay, I see - so you can define hyperrationals and the IVT does apply to functions over hyperrationals but when you pull back the standard part of a hyperrational you might find you no longer have a rational number. Hmmm ... these non-standard proofs seem to have a few traps for the unwary. I still prefer the standard proofs - they might be longer, but their assumptions are visible up-front. Gandalf61 (talk) 14:21, 2 September 2008 (UTC)

As far as uniform continuity is concerned, a rigorous explanation can certainly be written down to explain why x² is not. My point was that there is built-in logical complexity here, represented by the sheer number of the quantifiers, which usually baffles the average student. One argument in favor of infinitesimals is that all this foundational work is done once and for all in the construction of the hyperreals. The epsilon-delta arguments we are all so good at, from the non-standard viewpoint, are merely tedious repetitions of the same thing, combined with the fact that one repeatedly has to solve an inverse problem, which is notoriously difficult (can you hear the shape of a drum?). Katzmik (talk) 15:07, 1 September 2008 (UTC)

I hate to disagree with Katzmik, but personally I find the epsilon-delta definition of uniform continuity much easier to understand than the non-standard reals version. JRSpriggs (talk) 16:25, 1 September 2008 (UTC)

I responded at your page. Katzmik (talk) 12:56, 2 September 2008 (UTC)

As per the size of this discussion, I thought a more appropriate place may be at the talk page of non-standard calculus. I copied the discussion over to that talk page. Please make any additional comments there. Katzmik (talk) 12:12, 3 September 2008 (UTC)

Details....

I'm too rushed to check over this edit right now; could someone who's not so rushed take a look? Michael Hardy (talk) 11:53, 4 September 2008 (UTC)

Seems to be just a reorganizing of the identities and some layout stuff. (TimothyRias (talk) 19:54, 4 September 2008 (UTC))

Fibre Bundle

It is very sad news to hear of the death of user Oded Schramm; it was a pleasure to collaborate with him. I can't believe that I posted a message on his talk page on the very day of the tragic incident.

I am somewhat worried about the standards of the article on fibre bundles. Could someone please have a look at the last section on User talk:OdedSchramm. I have included some reasons as to why I think that the article is unsatisfactory.

I remember that Oded was keen to improve the article on End (topology) so perhaps we should work on that.

Topology Expert (talk) 07:14, 5 September 2008 (UTC)

MTAA again

Regarding various attempts to appease the WP:MTAA-pushers, some mathematics articles now have little hatnotes indicating what sort of background would be helpful to understanding the contents of the article or a section of the article. Quite recently, there was a discussion at the pump in which one of the possibilities suggested (and, I suppose, endorsed by a plurality of editors) was to consider this as an alternative to "dumbing down" articles.

I bring this up because of this edit to Clifford algebra, in which the note

Some familiarity with the basics of multilinear algebra will be useful in reading this article

was removed, with the edit summary

see Wikipedia:Manual_of_Style_(mathematics)#Writing_style_in_mathematics and also no disclaimers in articles.

I am inclined to revert this, but I wanted to submit it first for some community input, since after all User:Cenarium does have a point. siℓℓy rabbit (talk) 20:24, 3 September 2008 (UTC)

Well, I'm for WP:NCD and against silly little notes. Richard Pinch (talk) 21:18, 3 September 2008 (UTC)

Me too. If I see a disclaimer, I'm killing it. Ozob (talk) 21:24, 3 September 2008 (UTC)

Let's tread a little lightly here. There's always going to be a tension between us and the populist faction, but we don't want relations to break down completely. These hatnotes are not extremely lovely, but they don't really hurt anything; they're much less obnoxious than {{technical}} templates or (worst case) outright removal of content on the grounds that it's too difficult. And arguably they do serve a useful function. --Trovatore (talk) 23:15, 3 September 2008 (UTC)

I think that some kind of note could be useful, though the redundancy of the phrasing bothers me a bit. I wonder if it would be better to have a template for this (which might put the content in a box or italicize it), which has several benefits:

• Standardized formatting across different articles
• If it's sufficiently distinctive, people with background will instinctively skip it
• If a strong consensus appears to remove the notes, they can be bot-deleted
• Otherwise, the template can contain an id so editors who are bothered by the notes can add a line to their user css file to not show them.

CRGreathouse (t | c) 13:06, 4 September 2008 (UTC)

I mentioned this at Wikipedia talk:No disclaimers in articles, and someone is saying this doesn't constitute a "disclaimer" in the intended sense. Michael Hardy (talk) 13:20, 4 September 2008 (UTC)

A closer reading of WP:NCD reveals the following sentence: "For the purpose of this guideline, disclaimers are templates or text inserted into an article that duplicates the information at one of the five standard disclaimer pages". So I have to agree that the proposed hatnotes are not disclaimers in the sense intended by the guideline.

That said, I'll still remove them on sight. A properly written article needs no such hatnote; the proper fix for this problem is a wikilink somewhere in the body of the article. Ozob (talk) 17:59, 5 September 2008 (UTC)

I'd like to emphasize that the disclaimers NCD talks about are formal disclaimers, not at all content-related. So, please be accurate.

That said, I disagree with Ozob and Richard Pinch above. It is a fact, sad or not, that writing an article for an audience ranging from kids to PhD holders in the subject matter is hardly possible, in the sense that it is possible, but will severely hinder a satisfying reading experience for every reader. As it is, there are topics (such as general relativity) which are interesting to a wide audience, but at the same time technically demanding), which, in presence of enough willing editors, calls for a treatment of the topic in two different ways. A hatnote at the beginning of such an article is IMO not "silly" but a service to orient the reader to the page he is looking for. Jakob.scholbach (talk) 19:09, 5 September 2008 (UTC)

Oded Schramm

I have learned with great shock about the death of Oded Schramm, a fine mathematician and an outstanding contributor to Wikipedia. Arcfrk (talk) 22:00, 3 September 2008 (UTC)

That's a great loss. Maybe we could have a collaboration on one of the planned articles on his user page. --Trovatore (talk) 23:29, 3 September 2008 (UTC)

This is indeed very sad news. A fine mathematician indeed. Please count on me in whatever way I can contribute.--CSTAR (talk) 01:59, 4 September 2008 (UTC)

PS I couldn't find an obituary or any mention of his death other than the mention in Wikipedia. Is there any independent confirmation for this?--CSTAR (talk) 02:07, 4 September 2008 (UTC)

There is now a reference in the article to Terence Tao's blog, but Tao's blog links to the Wikipedia article for the information. The only non-circular reference so far I've seen is a remark, in an edit summary by somebody with exactly 3 edits on Wikipedia, that Henrique Malvar informed him of Schramm's tragic accident. Malvar's webpage last I checked 30 minutes ago made no mention of this fact. If User:Arcfrk has been directly informed by somebody, then I we should take that as satisfactory evidence.--CSTAR (talk) 02:41, 4 September 2008 (UTC)

It's also mentioned with equally circular sourcing on Luca Trevisan's blog. —David Eppstein (talk) 03:00, 4 September 2008 (UTC)

I have heard independently from one of his mathematical collaborators. Thenub314 (talk) 10:16, 4 September 2008 (UTC)

I felt reluctant to do it at first, but I in the interest of presenting the facts, I have posted at Talk:Oded Schramm a letter from Yuval Peres that gives some details. Arcfrk (talk) 03:02, 4 September 2008 (UTC)

Very sad news indeed, but it has been confirmed by two newsarticles[1][2]. Nsk92 (talk) 13:32, 4 September 2008 (UTC)

See OdedSchramm (talk · contribs). JRSpriggs (talk) 05:49, 4 September 2008 (UTC)

(unindent) I would suggest - following Greg Lawler in his 2005 AMS book - moving Stochastic Loewner evolution to Schramm-Loewner evolution (i.e. that an administrator could please exchange the article and the redirect). Oded was one of the greatest mathematicians of his generation. Mathsci (talk) 08:43, 5 September 2008 (UTC)

Likely COI book-pushing

User:Htim has been adding books written by somebody named Grossman to a variety of articles, including Average, Mean, and Statistics. There are no doubt better, more authoritative, references that can be provided for these articles. However prior to the new addition, the references at each of these articles were quite weak or nonexistent, so I was reluctant to revert Htim's addition. Could somebody here with a better knowledge of statistics please replace these sources with better ones? siℓℓy rabbit (talk) 12:30, 5 September 2008 (UTC)

I replaced the reference with one to Hardy, Littlewood, and Polya, which includes a chapter on averages. Still the articles average and mean could use some better references if anyone here has any recommendations. siℓℓy rabbit (talk) 12:54, 5 September 2008 (UTC)

He may be a meatpuppet of User:Smithpith, and I have a memory of him editing calculus anonymously at one point. I believe that he is a mostly harmless crank. He seems to operate in only one way, namely introducing references to books on so-called "Non-Archimedean Calculus" into calculus and its relatives. His real name may be either Michael Grossman or Robert Katz (these are the authors of the books he pushes). So far as I know he's never tried to communicate with the rest of us, despite the messages on User talk:Smithpith. Fortunately he doesn't edit often, and when he does it is easy to clean up. I don't think he's worth worrying about. Ozob (talk) 17:43, 5 September 2008 (UTC)

I am not really an expert on statistics, but the book "Mathematical Statistics and Data Analysis" by John A. Rice was the standard reference for basic grad statistics classes where I did my graduate work. It seems to be a good reference from what little I have read of it, but maybe an actual statistician would disagree. Thenub314 (talk) 06:21, 6 September 2008 (UTC)

Matrix ordinary differential equations

The article Matrix ordinary differential equations seems to be about ordinary differential equations or maybe systems of ODE's. In any case the ordinary differential equations article does a better job. Does anyone else agree this article should be deleted? Thenub314 (talk) 08:41, 6 September 2008 (UTC)

I am not an expert on differential equations but I think that the article should not be deleted. Perhaps further expansion of the article may reveal some interesting aspects of this form of ODE's using matrices. However, I am not the one to decide so you should probably consult some experts on the subject.

Topology Expert (talk) 08:59, 6 September 2008 (UTC)

In its present form, the article's in pretty bad shape, and I can't have much confidence in the person writing it given the misuse of the term "random variable" and other infelicities of language. Michael Hardy (talk) 21:20, 6 September 2008 (UTC)

It's not even a matrix ODE, it's a vector ODE. I vote for deletion. Loisel (talk) 21:27, 6 September 2008 (UTC)

True: it's about derivatives of vector-valued functions, not of matrix-valued functions. And don't we already have an article on this topic somewhere? Michael Hardy (talk) 03:34, 7 September 2008 (UTC)

Hmmm. Perhaps something could be done. I've seen the term used for a linear system of ODEs. — Arthur Rubin (talk) 22:36, 6 September 2008 (UTC)

Perhaps, ask the person who created the article for a reference. If he has seen this definition somewhere in a book then it is likely that the subject is important.

Topology Expert (talk) 04:17, 7 September 2008 (UTC)

Something could be written. Matrix-valued ODEs appear in

• (real variable) gauge theory and the parallel transport formula along a geodesic written in the form $dg/dt=A(t)g(t)$
• (complex variable) conformal field theory and the theory of generalized hypergeometric functions through the reduced Knizhnik-Zamolodchikov equations where the complex differential equation takes the form $dg/dz=(P/z+Q/(z-1))g(z)$ (an equation with regular singular points).

These are just two examples, both related to the theory of connections on an appropriate space. The theory of generalized hypergeometric functions is nineteenth century mathematics going back to Thomae, but it has been extensively developed in modern times by Aomoto, Gelfand, Varchenko, etc. Mathsci (talk) 04:23, 7 September 2008 (UTC)

(I've deleted my previous comment here, it was nonsense.) The term matrix differential equation could apply to equations involving derivatives of matrix functions with respect to a matrix variable OR to equations involving element by element derivatives of matrices with respect to a scalar variable. The latter meaning is used in the articles matrix exponential and ordinary differential equation#Linear ordinary differential equations, but I think the current content of Matrix ordinary differential equation should be deleted and replaced with equations involving derivatives of matrix functions. There should be articles about both types of derivative. The other one could be Matrix ordinary differential equation (element by element)Delaszk (talk) 23:36, 7 September 2008 (UTC)

Parallelogram law

Paraphrasing from parallelogram law:

Observe that if A, then B [by easy algebra].

......blah blah blah blah.......

A remarkable fact is that B only if A.

So someone comes along and changes this last "only if" to "if and only if". I think this obscures just which fact is being called "remarkable", and that is important. But he persists. Can someone do a better job of convincing this guy than I can? Or am I missing something? Michael Hardy (talk) 20:09, 6 September 2008 (UTC)

I actually think the other guy has a point. I never see "only if" used in isolation, and I actually paused to work out whether the second sentence is different from the first. His replacement, with the emphasis on "only", seems to me an adequate compromise between your desire to emphasize the converse portion of the statement, and his desire to use a recognizable phrase.

For a moment I thought this would be a relative of the "if and only if in definitions" argument that got resolved the wrong way some time ago :) Ryan Reich (talk) 21:02, 6 September 2008 (UTC)

I don't know how you've managed to avoid seeing "only if" in isolation. It's commonplace. Michael Hardy (talk) 21:16, 6 September 2008 (UTC)

The "only if" only version looks fine to me. Richard Pinch (talk) 21:27, 6 September 2008 (UTC)

Looks fine to me, too. It's standard to split an "if and only if" argument into the "if" part and the "only if" part, they are two separate results. --Tango (talk) 21:57, 6 September 2008 (UTC)

Yeah, and it's logical too, but its status in modern mathematical prose seems (to me) only a little more favored than that of "dividend" as an arithmetic quantity, and rather more than "subtrahend", in that older books use both, and newer ones will often go for the direct terminology of "B implies A" rather than "B only if A", which is circuitous ("dividend", by the way, becomes "numerator" or even "top", since no one is ever really sure which of the two parties in a ratio is the dividend and which the similarly-named divisor. A similar issue as with "if" and "only if", really). As for proofs of "if" and "only if" theorems, yeah, they sometimes say that...and the ones which are easier to understand give the entire statement of the direction they are proving. Of course, this statement wouldn't make it into an article because it's probably OR, and I can't give any firm sources — only my opinion. That opinion being that, whether or not "only if" is really so commonplace, it's excessively jargonish and a little hard to unravel. Ryan Reich (talk) 22:02, 6 September 2008 (UTC)

That said, "if and only if" is very awkward in this particular sentence. I've made a sample correction that I think is cleaner than both alternatives. The thing is that if you're reading the article like a mathematician, of course you already have a conjecture (or the statement of the theorem, if it is known to you) forming in your mind, and the "if and only if" trips off the tongue: thus, "only if" seems to be finishing your own thoughts in this context. If you're not following along so closely, the sudden implicit assumption of an unstated "if" counterpart to the "only if" is jarring. I think the flow of logic is better simply by phrasing the sentence "if parallelogram law, then inner product space". It doesn't connect quite as strongly to the previous text as Michael Hardy's sentence, but it is easier to understand the statement itself, and once that is done, the connection is clear (if you've actually been reading the article linearly). Ryan Reich (talk) 22:24, 6 September 2008 (UTC)

Ryan wrote "no one is ever really sure which of the two parties in a ratio is the dividend and which the similarly-named divisor". This one's easy. Words ending in -nd are derived from latin gerunds, meaning nouns derived from verbs denoting things to which the action of the verb is or ought to be applied. Examples turned into English: addend, dividend, integrand, multiplicand, summand. Examples in Latin used directly in English: Agenda (pl), corrigendum, referendum (sing.), referenda (pl.). Words ending in -or denote things performing the action of the verb. Hence

• dividend = thing to be divided = numerator = top line
• divisor = thing doing the dividing = denominator = bottom line

• minuend = thing to be diminished = thing before the minus sign
• subtrahend = thing to be subtracted = thing after the minus sign

Almost all English gerunds are derived directly from Latin and so end in -nd. For extra credit, find two English words which are gerunds, ending in -ing. Richard Pinch (talk) 06:29, 7 September 2008 (UTC)

500 most viewed articles

The idea of keeping track of a project's 500 most viewed articles is a great one, and something I'd love to do for WP:FOOTY. I think it would lend our project (and Wikipedia) a great deal of credibility if we could divert some effort into improving the most viewed articles. Please could someone let me know what is involved in setting this up? Many thanks. --Jameboy (talk) 23:49, 6 September 2008 (UTC)

You want to get hold of the latest stats from http://dammit.lt/wikistats/, then filter to get those records starting with en. Next cross reference with a list of articles from your project, sort and format. --Salix alba (talk) 10:11, 7 September 2008 (UTC)

Is Squoval mathematics?

While using Jitse Niesen (talk · contribs)'s random math page utility, I found Squoval which is in the mathematical Category:Geometric shapes. It is rather unusual for a math article. :) JRSpriggs (talk) 01:41, 7 September 2008 (UTC)

According to a google search, all or nearly all uses of this word refer to a shape in fashion or fingernails. So, no, I don't think this is a legitimate mathematical term. I have removed it from the category. siℓℓy rabbit (talk) 02:21, 7 September 2008 (UTC)

Does it have to be a mathematical term to be in Category:Geometric shapes? Omitting it from Jitse Niesen's utility may be appropriate but not if it is achieved by removing it from an otherwise useful category. PrimeHunter (talk) 03:13, 7 September 2008 (UTC)

I am of the opinion that it should be a mathematical term, or at least a mathematical notion, in order to belong to the category. The article (and my google search) fail to establish any mathematical or geometrical uses of this term. If the category were Category:Fashion shapes or Category:Nail shapes, then it could potentially be included. But it is misleading (and I don't see what purpose is served) to include it in a category of Category:Geometric shapes, when the concept has nothing at all to do with geometry. siℓℓy rabbit (talk) 03:21, 7 September 2008 (UTC)

I agree: the term seems ill-defined, and as such not appropriate for the category. At first I thought the article was a relative of the squircle which would make it fair game -- but it wasn't. CRGreathouse (t | c) 06:28, 7 September 2008 (UTC)

I'm inclined to say that is is a geometric shape. It may not be a mathematical term, but that's not the same thing. Richard Pinch (talk) 11:15, 7 September 2008 (UTC)

I agree that in casual discourse we may wish to call this a geometric shape. That still doesn't justify including it in the category Category:Geometric shapes. Doing so is quite misleading, because it throws this in along with other shapes which are mathematical terms. Then there is the issue of criteria for inclusion in the category. I'm inclined to say that a reasonable criterion is that the shapes listed must have some documented use in geometry, otherwise there is no need for the word geometric in the category title. siℓℓy rabbit (talk) 12:35, 7 September 2008 (UTC)

Group objects, topological groups vs. groups

In the current FAC of group (mathematics) there is a (friendly) dispute between Stca74 and myself what the importance should given to group objects and topological groups in the said article. As the main contributor to the article I consider myself biased, but am also not convinced by Stca's wish to have more on these topics. So, I'd like to hear other opinions on that matter (please comment at the FAC page). Thanks, Jakob.scholbach (talk) 20:08, 7 September 2008 (UTC)

"Software for calculating π" nominated for deletion

Perhaps this case could benefit from comments by mathematicians and others interested in mathematics. Post comments at Wikipedia:Articles for deletion/Software for calculating π. You should first say either Keep, Delete, Comment or any of the various other courses of action, but do not stop there; state your reasons and arguments. Michael Hardy (talk) 18:45, 8 September 2008 (UTC)

Wikipedia:Math Sandbox

Is there a need for Wikipedia:Math Sandbox? Suntag (talk) 02:53, 9 September 2008 (UTC)

What did you have in mind? Richard Pinch (talk) 22:29, 9 September 2008 (UTC)

I believe the question is whether the currently existing page Wikipedia:Math Sandbox should be allowed to continue to exist. I'm inclined to vote delete, since the page has hardly ever been used at all, and doesn't have the proper headers for a sandbox anyway. siℓℓy rabbit (talk) 22:37, 9 September 2008 (UTC)

And there is nothing meaningful in Special:WhatLinksHere/Wikipedia:Math Sandbox. Looks like a WP:CSD#G2 candidate to me. PrimeHunter (talk) 14:59, 10 September 2008 (UTC)

Could it be that it's never been used because no one knows it's there? Maybe people learning how to use TeX on Wikipedia could be directed there to practice. Michael Hardy (talk) 20:01, 10 September 2008 (UTC)

Errett Bishop

Does the Bishop-Keisler controversy deserve a special wikipage? There is an intriguing episode in the history of mathematics, or perhaps it is the epistemology of mathematics, or rather the polemics of mathematics. At any rate, Errett Bishop represents the constructivist school, whereas Abraham Robinson and H. Jerome Keisler represent non-standard analysis. The fields are polar opposites of each other. It is interesting to observe that two people with very similar training in classical mathematics, can arrive at such different conclusions as to the nature of the mathematical trade. I placed the following comments at Errett Bishop and am wondering what you think about the possibility of a separate article.

Metamathematically speaking, Bishop's constructivism lies at the opposite extreme of Abraham Robinson's non-standard analysis in the spectrum of mathematical sensibility. Bishop's criticism of the latter was therefore to be expected. In '77, Bishop wrote an intriguing review of H. Jerome Keisler's book Elementary Calculus: an infinitesimal approach. The review appeared in the mainstream Bulletin of the American Mathematical Society.

Bishop first provides the reader with an assortment of quotations from Keisler:

"In '60, Robinson solved a three hundred year old problem by giving a precise treatment of infinitesimals. Robinson's achievement will probably rank as one of the major mathematical advances of the twentieth century."

Clearly in a disapproving fashion, Bishop quotes Keisler to the effect that

"In discussing the real line we remarked that we have no way of knowing what a line in physical space is really like. It might be like the hyperreal line, the real line, or neither. However, in applications of the calculus, it is helpful to imagine a line in physical space as a hyperreal line."

Getting down to business, Bishop describes Keisler's introduction of infinitesimals in the following terms:

"The impasse is broken by forgetting that Δx is a real number, calling it something else (an infinitesimal), and telling us that it is all right to neglect it."

Bishop proceeds to refer to the theoretical underpinnings of non-standard analysis as "a supposedly consistent system of axioms". Toward the very end of the review, Bishop finally goes for the guttural:

Is "goes for the jugular" intended here? Plclark (talk) 16:16, 3 September 2008 (UTC)

"The real damage lies in [Keisler's] obfuscation and devitalization of those wonderful ideas."

In a final passionate appeal, Bishop notes:

"Although it seems to be futile, I always tell my calculus students that mathematics is not esoteric: It is common sense. (Even the notorious ε, δ definition of limit is common sense, and moreover it is central to the important practical problems of appoximation and estimation.)"

As a response, Keisler published a 10-page practical guide describing the success of "Elementary Calculus: an infinitesimal approach" in the classroom. Katzmik (talk) 12:55, 3 September 2008 (UTC)

Should not the article say something about the influence or absence of influence of other constructivists on Bishop, and he on them? See Constructivism (mathematics)#Mathematicians who have contributed to constructivism. JRSpriggs (talk) 14:31, 3 September 2008 (UTC)

I wish I knew something about this :) Would you like to give it a try? Katzmik (talk) 14:33, 3 September 2008 (UTC)

Sorry, I know less about it than you do. I just noticed that the article did not mention any relationships with other mathematicians, except the bit you added, and Bishop's father. Yet there are several other influential constructivists, especially Luitzen Egbertus Jan Brouwer. Surely, there must be some connection. Do they use each other's work or reject it? JRSpriggs (talk) 14:42, 3 September 2008 (UTC)

Arend Heyting would be one of the other mathematicians that one would want to mention; He took up Brouwer's ideas and formlised them (something which Brouwer disapproved of, since he preferred to think in purely intuitive terms and not reduce things, as Heyting did, to something ecplicitly formalisable; I believe Brouwer referred to Heyting's work as "a dry exercise" or some such). How Bishop fits in with that is not clear to me (I don't know a great deal about this topic either unfortunately), but it seems to follow more from Heyting's approach than Brouwer's. It would be good if someone could fill in these details in the article, it would be helpful. -- Leland McInnes (talk) 21:14, 3 September 2008 (UTC)

I am not too familiar with the work of Arend Heyting, but the constructivist theory of Bishop is more reserved then that of Brouwer. For example it is a theorem in Brower's set up that every function is continuous, while this is not a theorem in Bishop's setting. Bishop's setting one simply eliminates the law of excluded middle (the axiom that "a statement" or "the statement's negation" is always true statement). This of course has profound impact on what can be proved, etc. But all theorems reachable from this setting are still true from a formalist prospective. Interestingly around the time of Brouwer, other mathematicians (most notably Kolmogorov) suggested other variants of constructive mathematics. To the best of my knowledge these produced theorems that were not necessarily true from the formalist prospective put forth by Hilbert. Thenub314 (talk) 06:43, 6 September 2008 (UTC)

Interesting question. What I was mostly concerned with here, however, was a battle opposing a constructivist and a infinitesimalist. Katzmik (talk) 15:18, 3 September 2008 (UTC)

Please move this over to Talk:Bishop-Keisler controversy. Charles Matthews (talk) 17:08, 11 September 2008 (UTC)

Tessarine

I came across the Tessarine article, which references papers by James Cockle (the person who introduced them). I haven't been able to find any other references to them though (Google books and Google scholar come up virtually empty for instance). Are they known by another name, or failing that, are they notable enough to be included here? Cheers, Ben (talk) 16:38, 7 September 2008 (UTC)

Nominated for deletion here. Ben (talk) 08:17, 11 September 2008 (UTC)

Symmetric spaces

I'm revamping the article on Riemannian symmetric spaces so that it has better coverage of general symmetric spaces, which are pretty important these days. I'd like to move it to "Symmetric space" but I can't because the latter was set-up years ago to disambiguate the alternative meaning of symmetric space as a synonym for R0 space in general topology. I checked "What links here" and there seem to be no cases where there's a link to "symmetric space" in the sense of R0 space (which is hardly surprising, given that symmetric spaces in geometry, representation theory and harmonic analysis are just way more prevalent than this synonym). Can someone help me with the move? Nilradical (talk) 20:01, 11 September 2008 (UTC)

It looks like you already moved Symmetric space to Symmetric space (disambiguation). That appears sensible. Now, if you wish, it looks like you could move Riemannian symmetric space to Symmetric space over the redirect. If there is no objection here, you might as well proceed with the move. Ask any admin to help if the move doesn't go through. EdJohnston (talk) 20:29, 11 September 2008 (UTC)

I tried that, but I can't move over the redirect because the redirect doesn't redirect to Riemannian symmetric space. I think it needs an admin. Nilradical (talk) 21:30, 11 September 2008 (UTC)

I moved it. — Carl (CBM · talk) 21:42, 11 September 2008 (UTC)

Many thanks! Now we just need to make it live up to expectation! Okay, I guess I have some work to do... Nilradical (talk) 21:45, 11 September 2008 (UTC)

Articles needing expert attention list.

I am a bit confused. I was looking for something to do, and looking through the list of articles needed expert attention, I decided to take a look at Gibbs phenomenon. I found it to be a pretty good article. I improved where I thought I could, but when I looked at the article I didn't see where that tag for needing expert attention appeared. Are articles automatically added and removed from this list? Is there a delay? etc. Thenub314 (talk) 12:32, 12 September 2008 (UTC)

I am not aware of any automatic process for updating Wikipedia:Pages needing attention/Mathematics#Articles needing expert attention, so each member of this project is on his own. Add articles to the list and use the Template:Expert or Template:Expert-subject when needed; and remove them from the list and remove the template when help is no longer needed! It is up to you! JRSpriggs (talk) 08:07, 13 September 2008 (UTC)

Most of the above page is transcluded Wikipedia:Pages_needing_attention/Mathematics/Lists which is automatically generated by User:Jitse's bot. The delay is about three days, I don't why the article is still listed. It may well be a bug.--Salix alba (talk) 09:44, 13 September 2008 (UTC)

Naive statements in mathematical diagram

I recently removed a few naive statements from the article mathematical diagram (including one that stated that "geometric" fields used more diagrams than "algebraic" ones). The author has insisted on adding one back: "With the development of Frege's predicate calculus and Hilbert's formalization of mathematics end 19th century, according to Zenon Kulpa (2004), diagrams went out of fashion and where considered bad practice until recently." This is news to me and a lot of mathematicians. According to Zulpa's writings (when I look at Zulpa's webpage), very few mathematicians use diagrams. Note that diagram here is also defined broadly to include any kind of chart or schematic, so this would include graphs and commutative diagrams. I think the author of mathematical diagram is taking a lot of Zulpa's claims without a grain of salt, so I invite those interested to make their comments on the talk page. --C S (talk) 01:01, 14 September 2008 (UTC)

Variable format

Resolved

 – Discussion centralized here.

("Resolved" above only means the discussion has been moved elsewhere, not that people aren't still arguing about it.) 75.72.179.139 (talk) 23:06, 13 September 2008 (UTC)

There is a newly changed section in a MOS subpage, here, which would require that we use <var></var> instead of simple italics when mentioning variables in plaintext. As far as I can tell, the two methods have exactly the same effect on displayed text. There is a proposal to merge the new text closer to the main MoS here.

While this is largely harmless beating around the bush, and would have advantages if we ever decided to do anything with such variables other than italicizing them, I wonder whether mathematics editors are ever likely to do this in practice. Comments (probably most useful at the merge proposal) are welcome. Septentrionalis PMAnderson 19:18, 12 September 2008 (UTC)

It's not harmless. Imagine writing a short math article that included 75 occurrences of variables. This change could make it take 20 minutes longer.

Note that:

• • This policy changed was done unilaterally with no discussion, by a person who doesn't edit Wikipedia math articles.
  • The proposed merger into Wikipedia:Manual of Style (dates and numbers) is to the wrong manual. This topic belongs in Wikipedia:Manual of Style (mathematics). It's almost as if this person doesn't know the difference. Is this person a high-school graduate?

Michael Hardy (talk) 21:21, 12 September 2008 (UTC)

He claims to hold a college degree in engineering, and berates the views on English of his liberal-arts professors; he also asserts expertise in website design, which supplies the justification of the change. Septentrionalis PMAnderson 21:36, 12 September 2008 (UTC)

I can see a benefit. It establishes a semantic markup as opposed to physical markup. It would allow users to format varibles as they wish, for example in a serif font to match the tex. Typing could be marginally reduced with a template {{var|x}} say.

I'm not sure if its related by a couple of new templates have appear {{math}} and {{bigmath}} which use the texhtml CSS class. --Salix alba (talk) 22:50, 12 September 2008 (UTC)

What do those new templates do? I looked at them and I find nothing to indicate that they have any ability to do anything. Michael Hardy (talk) 23:46, 12 September 2008 (UTC)

Would such a template cause variables to get italicized while leaving digits, parentheses, etc. unitalicized, and also things like "cos", "max", "lim", "det", "log" etc. unitalicized? What are the advantages of a "semantic markup"? Those are just words. Can someone translate them into language? Michael Hardy (talk) 23:19, 12 September 2008 (UTC)

Salix alba explained the advantages of semantic markup in his next sentence. Algebraist 23:27, 12 September 2008 (UTC)

Well, it certainly wasn't obvious that his next sentence was intended to be on the same topic. So could we see some examples? Michael Hardy (talk) 23:38, 12 September 2008 (UTC)

Now I've entered "semantic markup" into the search box. It's a red link. Michael Hardy (talk) 00:01, 13 September 2008 (UTC)

Redir fixed. — SMcCandlish [talk] [cont] ‹(-¿-)› 00:16, 13 September 2008 (UTC)

True. HTML#Semantic HTML is probably what you want. I'm a bit dubious on making that a redirect though, as HTML is not the only markup language in the world. Algebraist 00:09, 13 September 2008 (UTC)

It's like the difference between, say, \textit and \emph: The former says, "Make this text italic," while the latter says, "Emphasize this text." The advantage of <var> would be that it says, "This is a variable," which might in theory produce different results than the present approach, which is, "Make this text italic."

In my opinion, unless this is backed up by some serious support, like a {{var}} template (or maybe call it {{math}}? Or would that be confusing) which will properly unitalicize parentheses, and unless the person making this change asks the rest of us first, then this change is no good and needs to be reverted. Ozob (talk) 00:12, 13 September 2008 (UTC)

(reply to Michael after ec) Best link I can find easily is HTML#Semantic_HTML. Presentation markup: markup on how things appear, semantic markup: markup based on the meaning. The big thing with CSS was to seperate apperance from meaning. So with presentation markup ''x'' says x is in italics. <var>x</var> says x is a varible (which will be formatted in italics).

You need to look at the source code of the {{math}} template to see what it does <SPAN CLASS="texhtml" >{{{1}}}</SPAN >. It gives its content the CSS class of "texhtml", this is the same as that used in <math> when its rendered in html rather than as images.

No the templates are not smart enough to distinguish functions from variables. --Salix alba (talk) 00:22, 13 September 2008 (UTC)

The following response is copy-pasted from Wikipedia talk:Manual of Style (text formatting)#Variable markup, and I would suggest that discussion be centralized there, since it is about that MOS page's wording (not at WT:MOSNUM, which is only discussing whether a merge makes sense structurally, and not here because this page is a WP:MATH house organ).

It's not a "new policy"; this isn't a policy to begin with, it's a guideline. Getting hot around the collar about "policy" is a hyperbolic red herring. If someone has a problem with semantic markup, take that up with the W3C, since said someone has a problem with XHTML in general. If someone finds <var>...</var> too inconvenient to do somehow, then don't do it; some gnome will fix it later. It's not like much of anyone but gnomes pays any attention to this or other MOS pages. And please keep it civil and a lot less WP:OWNish. I'm no noob nor an "outsider"; I've been editing MOS pages for years. Just because a handful of editors seem to sometimes like to treat this particular MOS page as if it were somehow magically special does not make it immune from editing by others, much less those with legitimate concerns that math-focused editors may be unaware of, not fully understand, or simply ignore because they aren't personal concerns of those editors or they do not personally see the benefits to resolving them. One such concern is failure in various places in Wikipedia to use the XHTML semantic phrase elements for what they were intended for, an oversight that has implications for accessibility, metadata, the semantic Web, external repurposing of Wikipedia content, etc., etc. Just because this guideline touches on mathematics in a few places does not mean it should be dicated by the convenience of math editors.

If you find <var>x</var> too difficult in some way, try {{VAR|x}} (same output). Given that some editors simply won't care, I don't see a problem with the guideline being more flexible (will edit it in a minute to do so). The fact that this was discussed 5 years ago, before many Wikipedians were thinking about Web semantics, Web 2.0, accessibility, repurposing of content, metadata, and using simple inline templates to ease repetitive keyboarding tasks, isn't particularly persuasive. "It's more convenient the sloppy way" is not a strong argument against doing something properly. I'm frankly shocked that mathematics editors would even use such an argument to begin with, given how insistent they are that the codes and conventions they use be done with absolute precision, to the great inconvenience of all other editors (who do not notice or recognize any difference between the minus and hyphen characters, etc.). I also have to ask how many new articles are being created that use italicized variables 75 times? Surely not many. I'm also skeptical about the claim that such an article would require an extra 20 or 30 minutes to write as a result; this would only be true for someone who doesn't know how to copy-paste. As I said, a gnome (or a bot) can fix it later, so it really doesn't matter if some editor will ignore the var recommendation. If someone finds even the template version tedious, a simple solution is to write the article in a text editor, and use \\x\\\ as a temporary token, instead of ''x'', and then simply search/replace all instances of \\\ with and \\ with <var> (in that order), once each, and it'll change document-wide. I do this sort of stuff all the time. Try it. Major time-saver for all sorts of things.

For anyone not following any of this at all, I'm not sure what to tell you other than to spend some time actually reading on the topic before dismissing it. Use of semantic markup has been one of the basic principles of web design, development and publishing (i.e., what Wikipedia is doing) since the mid-1990s. For some quick intros, see Separation of content and presentation here, and some concise W3C material on the topic. Be also aware that screen readers for people with visual problems will usually ignore italics (and bold and other non-semantic markup), but will usually indicate, one way or another, when something is marked up with one of the semantic elements. Intentionally ignoring simple semantic markup in favor slightly-simpler non-semantic markup is really pretty blatantly anti-accessibility. Let's not go there!

— SMcCandlish [talk] [cont] ‹(-¿-)› 00:16, 13 September 2008 (UTC)

PS: It's not an "in theory" matter, but an "in actuality" matter; the fact that most regular readers don't see a visual difference doesn't mean there isn't any difference. — SMcCandlish [talk] [cont] ‹(-¿-)› 00:47, 13 September 2008 (UTC)

Quote:

If you find <var>x</var> too difficult in some way, try {{VAR|x}} (same output).

That's a weird suggestion. Repeatedly typing {{VAR|x}} is as bad as repeatedly typing <var>x</var>. OK, so you say there are concerns that math editors may not know about, and that somehow the simpler way of doing things impairs accessibility. Can those statements impress anyone if you don't say specifically what those concerns are or how accessibility could be impaired? Michael Hardy (talk) 02:16, 13 September 2008 (UTC)

Replying at here. We don't need to hash this out on three different talk pages. — SMcCandlish [talk] [cont] ‹(-¿-)› 02:27, 13 September 2008 (UTC)

I reject this crap. Loisel (talk) 10:10, 14 September 2008 (UTC)

Variable markup

Since the above thread is a bit frayed, I'd like to invite everybody caring about reasonable math markup to have a look (and comment) at Wikipedia_talk:Manual_of_Style_(text_formatting)#Variable_markup. The matter is a guideline requiring writing variables such as x not anymore simply like ''x'', but as <var>x</var> or {{var|x}}.

I, personally, think that the math community here should react unisono that installing such guidelines, especially without talking to us, is unhelpful, to say the least. Jakob.scholbach (talk) 00:44, 14 September 2008 (UTC)

SMcCandish appears to have two arguments:

• • His proposed new style is more cumbersome than the one now used but produces the same results, and also there are also other reasons to prefer the new style besides that (and he says he could tell us what those other reasons are). (This seems really weird, but he really did say that. Go to that other page and see for yourself!)
  • Isn't it enough to know that math articles look like gibberish to a large number of people who would understand them if the new methods, which make them look the same as the old methods, were used? (He doesn't tell us who those people are or why they have that alleged problem; he gives us no reason to think they exist. I think he thinks we already know who they are and why they have that problem.)

Actually, I suspect he does have some reasons. But that he's not telling us what they are because he thinks we already know, and it's a complete surprise to him that we don't. Michael Hardy (talk) 01:09, 14 September 2008 (UTC)

Please just relax, folks. Nothing is going to fall apart as if by the evil touch of Sauron if this take a little while to play out. I've already stated that I will cover every detail if needed and I'm intentionally not assuming we are all on the same page. I'm not withholding information from you; it's well after 4 a.m. my time and I have a family reunion beginning tomorrow shortly after noon. Lots of cleaning and cooking, not so much WP typing. PS: I stated precisely who "those people are" - readers with screen reader software; so, I must just not be writing precisely enough if that was missed, and will try to be clearer next time. That might be ca. 2 a.m. Mon. ("late Sun. night" to some) or Mon. afternoon, Mountain Standard Time, after the family stuff has settled down. PS: I said I would be happy to explain all of the rationales for going this route if that's what is asked for; it's asked for so I will (at WT:MOSTEXT). It's not a "complete surprise" to me that I need to do so; I simply didn't want to presume that I needed to do so, since such a presumption might be insulting to some, especially given WP's unusually high web developer saturation. I'm not trying to tease or anything; I just don't like to be pedantic unless I have to, and have been unusually busy off-WP for the last day or so. PPS: The two methods do not produce the same results. They produce the same visual results. A photo of a pizza looks very much like a pizza (especially to someone with no depth perception :-), but has a different flavor and consistency, and much less nutritional value. Taking a polaroid is easier and faster than cooking, but surely one is preferable to the other on your dinner plate, yes? — SMcCandlish [talk] [cont] ‹(-¿-)› 10:30, 14 September 2008 (UTC)

This thing is crap. I reject it. Loisel (talk) 10:13, 14 September 2008 (UTC)

WP:IDONTLIKEIT. — SMcCandlish [talk] [cont] ‹(-¿-)› 10:36, 14 September 2008 (UTC)

Wikipedia:Don't overuse shortcuts to policy and guidelines to win your argument Staecker (talk) 11:22, 14 September 2008 (UTC)

And how is citing an essay about valid deletion arguments relevant? Certainly discussions that are determining consensus allow arguments of the form "I don't like this", otherwise how would we ever determine if a lot of people like some proposed policy? --C S (talk) 11:26, 14 September 2008 (UTC)

If using var becomes a guideline it will be largely ignored. Not everyone has the time to devote to such nicities.Delaszk (talk) 13:02, 14 September 2008 (UTC)

To say nothing of the problem of making more than 10000 articles compliant with a new guideline. No thanks. This proposed guideline may be fine for an article that contains two or three inline equations, but for the thousands of articles that each already have hundreds of equations, I just don't see that the perceived benefit of "the readers won't even notice the difference" outweighs the drawback of "thousands of editor-hours will be spent bringing existing articles into compliance with the new guideline". Unless SMcCandlish personally has a cadre of umpalumpas who are going to be doing this. siℓℓy rabbit (talk) 15:13, 14 September 2008 (UTC)

Well I personally see a drift in the opposite direction: massive bot edits (not always correct) which replace html markup for mathematical and typographical symbols (pi, endash, superscripts) with characters from extended font families. I think in both cases (whether new markup is introduced, or old markup is removed), any potential benefit is dwarfed by the cost of doing the changes, and let's not forget that stability of articles should count as a benefit. Arcfrk (talk) 17:50, 14 September 2008 (UTC)

Differential geometry of surfaces

I have raised the same issue before in this very forum: obnoxious and inflammatory comments by User:Mathsci, directed personally against other editors. Here are two recent edit summaries from "Differential geometry of surfaces":

• →References: Katzmik, please stop advertising or evaluating your own recent research!
• →Global differential geometry of surfaces: removing peacock term used by Katzmik to describe his own research

Can nothing been done to stop it? If there are legitimate concerns about biased editing, there are much better ways of addressing them than making personal attacks that stay forever as part of the history of the article (Mathsci's favorite way of treating his designated enemies). Does mathematical community on Wikipedia have enough spine to say "enough is enough"? Arcfrk (talk) 00:09, 8 September 2008 (UTC)

These appear to be simple 'housecleaning' edits with unexceptional edit summaries. Further, they appear to refer to standard policies WP:COI and WP:PEACOCK. Perhaps you could explain what about these is objectionable? CRGreathouse (t | c) 01:46, 8 September 2008 (UTC)

Their accusatory character, the fact that they are directed personally against another editor, the fact that they are embedded into edit summaries — I am repeating myself. Arcfrk (talk) 03:21, 8 September 2008 (UTC)

They look acceptable to me. Why shouldn't he tell someone to stop violating policy? --Tango (talk) 02:04, 8 September 2008 (UTC)

Why should he? It is far from clear to me whether Katzmik violated any policies. In fact, the two "policies" quoted above are not policies: COI is a "behavorial guideline" and PEACOCK is a "style guideline". (However, and your response is a clear confirmation of my point, Mathsci's summary makes it appear as if severe violations have been committed.) On the other hand, I do believe that by leaving inflammatory summaries of this kind, and more generally, judgmental comments personally directed against other editors, Mathsci himself violates the policy WP:Civility. Arcfrk (talk) 03:21, 8 September 2008 (UTC)

I don't care if you call it a policy or a guideline, it's good practice not to publicise your own work on Wikipedia and someone doing that should be told not to. --Tango (talk) 04:01, 8 September 2008 (UTC)

Let's put aside the question of the civility of MathSci's remarks: this does not seem to be a fruitful line of inquiry. I am more interested in the issue of violations of wikipedic policies/guidelines/philosophy in Katzmik's references to his own work. I can find no support for this position (especially, nothing in WP:COI). In my opinion his inclusion of his own work has been appropriately done and is a positive contribution. M. Katz is an acknowledged expert in the field of systolic geometry, which is an important subfield of the differential geometry of surfaces. In addition to almost 40 research papers on the subject published in the last 25 years, he has a recent book on the subject. Thus his own work seems to be unquestionably notable and relevant. Why shouldn't he include references to it in an article on differential geometry of surfaces? Plclark (talk) 05:16, 8 September 2008 (UTC)

Actually, the first link above looks like an ok edit, he just added more information to an existing reference. The 2nd one is more of an issue - describing your own work as "definitive" is a clear COI. --Tango (talk) 05:36, 8 September 2008 (UTC)

I agree, Plclark -- Katzmik was not out of line. I was addressing only the issue of Mathsci since that was the topic at hand. It is worth noting that no one has questioned the value of the reference, only the adding the Google Books link (which I don't like; I think unstable URLs should be used only as a last resort). Katzmik's wording describing his book seemed grandiose, just as Mathsci's wording was uninformative -- but that's just the normal evolution of the article. In short: what's the fuss? CRGreathouse (t | c) 14:10, 8 September 2008 (UTC)

I don't think "definitive" was intended as a superlative (or "peacock term"), but was rather meant to indicate that the result was best possible in some precise sense. The current phrasing "Results on the asymptotic behavior of the genus..." is distinctly less informative. Best would be to describe in what sense the result is optimal ("optimal" is not a peacock term!); I invite Katzmik to provide this information. Plclark (talk) 05:46, 8 September 2008 (UTC)

"Definitive" has a pretty clear meaning and it is a superlative (well, it's an absolute term, it's not really a comparison, but there is certainly nothing better than definitive). --Tango (talk) 06:27, 8 September 2008 (UTC)

(edent) This is not a forum for discussions about conduct. The principle of being very cautious about using ones own personal research is one that could and should be discussed here. I myself have preferred to leave it up to others to include references to my own work, and sometimes it doesn't get mentioned at all. That's life. Richard Pinch (talk) 06:40, 8 September 2008 (UTC)

Use of edit summaries to make sweeping statements about conduct strikes me as far less appropriate. Arcfrk (talk) 13:00, 8 September 2008 (UTC)

Yawn. I actually admire Katzmik: every remark he makes is pertinent and extremely helpful, if sometimes a little eccentric. He keeps other mathematical editors on their toes. I don't mind at all that he puts his own research on systoles on wikipedia, although perhaps some of the articles could be collected together. I had similar problems myself when editing Knizhnik-Zamolodchikov equations recently, but came up with a different solution. Some of my own work is cited on wikipedia, but not by me.

I hope nobody minds that I refactored the title of this section. Thanks, Mathsci (talk) 07:26, 8 September 2008 (UTC)

I do. I would prefer that you "refactor" your offensive edit summaries instead. Arcfrk (talk) 12:00, 8 September 2008 (UTC)

I have no opinion on the content issues, but I will agree with Arcfrk that it can be uncivil to refer to another editor directly in an edit summary. As is being demonstrated, it often tends to just escalate any dispute. Just as we often say on talkpages, "Please comment on content, not the contributors", the same goes for edit summaries. Now, having said that, I do agree that the Math WikiProject is not the place to address user conduct issues. Arcfrk, a better tactic is to diff your concerns directly to Mathsci's talkpage. --Elonka 13:52, 8 September 2008 (UTC)

For the definitive grandiose optimal controversy please see instead Bishop-Keisler:::. Katzmik (talk) 14:22, 8 September 2008 (UTC)

(unindent) Just a few comments:

• It is impossible to refactor edit summaries.
• It's great that Elonka is interested in mathematics again, but there's no dispute here except possibly for one person.
• I carefully consulted Katzmik about the material in the systolic section, which can alas never be optimal. Much earlier today I left comments for him on his talk page. A little while back Katzmik thanked me for my edits to differential geometry of surfaces. That made a nice change for me.

Mathsci (talk) 17:01, 8 September 2008 (UTC)

Comments by arcfrk

• In her post above, Elonka did not express any interest whatsoever in mathematics; she said "it can be uncivil to refer to another editor directly in an edit summary". You seem to have a habit of twisting the facts to suit your goals.
• There was a well-documented disputed involving you and Katzmik at "Differential geometry of surfaces", and it just appears from the sidelines that you are taking a revenge at him, using the edit summaries as a tool. This is consistent with the pattern of behavior where you attacked the editors who disagreed with you (including myself).
• Your good will at contacting Katzmik on his webpage explaining yourself is much welcome; it's also great to learn that you appreciate Katzmik's insights so much; but unfortunately, all this happened after your edit, and even I raised the issue here. If you had genuine concerns about his actions, posting them on his talkpage or (if you consider them severe violations) even bringing them up for discussion here first would have been far more appropriate, in my opinion. Now they are forever stuck in edit history. It is just your opinion, which many people disagree with, but it is worded very strongly and has acquired an undue weight by virtue of the location of its posting.

Suggestions for the future

• Since you recognize that it is impossible to refactor edit summaries, will you agree in the future to exercise extra caution in what you put in them? Unlike discussions here at WPM, which are editable and frequently archived, the edit summaries are immediately visible to anyone viewing the history of the article. For the record, I am stating my objection to using my name in the edit summary regardless of the content, and other people may feel similarly.
• If your goal is collaboratively improving wikipedia then alienating other contributors is definitely the wrong approach. Whether you perceive it or not, many of your comments come across as personal attacks and create a hostile environment. This has happened many times in the past, and still continues to happen. Will you agree to forgo making sweeping statements and attributing motives to other people in the future? Arcfrk (talk) 17:30, 9 September 2008 (UTC)

Suggestion for Arcfrk

As a very senior mathematical wikipedian privately noted, Arcfrk's account has devolved into that of "polite troll". His mathematical contributions at the moment are very minor. Why is he constantly abusing this page by creating wikidrama over trivial matters, in this case two edit summaries? If he expects to be taken seriously on WPM, he should improve the quality of his own edits. I have not noted any mention of mathematics in his submissions here, which I think proves my point. Perhaps these grievances should be taken up on a blog, but certainly not here. Mathsci (talk) 22:09, 9 September 2008 (UTC)

Mathsci, calling someone a troll is not helping matters. Now please, both of you, this WikiProject talkpage should be reserved for discussing mathematics articles. It is for content discussions, not conduct discussions. The proper venue for conduct discussions is to first provide evidence at someone's talkpage, and try to work things out there. If that doesn't address the issue, then post somewhere such as Wikipedia:Wikiquette alerts, or for urgent issues (which this is not), WP:ANI. Please stop discussing it here though, and let the other editors get back to work. --Elonka 22:24, 9 September 2008 (UTC)

In my view those edit summaries were inappropriate. Paul August ☎ 17:23, 8 September 2008 (UTC)

If Katzmik was not offended, I don't quite understand your point. It was highly inappropriate and uncivil of Arcfrk to raise this issue here, without informing me. I found out by accident. Mathsci (talk) 17:38, 8 September 2008 (UTC)

Please, take this to WP:WQ or WP:DR or WP:DIS or ... well, just about anywhere but here. Please? Richard Pinch (talk) 17:37, 8 September 2008 (UTC)

I think there is something to be gained if some disputes are given some aring amongst a pier group (here). Even if the eventual message is basically: your all being silly, try to be nicer to each other, be aware that online comunication misses the subtitle signals in speech and hence can be easier to be inflamitory, especially when it cannot be undone (without admin intervention). Hopefully this page has help quell a few editor disputes in the past, preventing other forms of dispute resolution. If this page can work like that then it does help in maintaining the mainly good atmosphere among maths editors which in turn helps in the improvement of articles. --Salix alba (talk) 23:16, 9 September 2008 (UTC)

When there is no conflict between editors, why try to stir one up? Why not spend time making sure your own main space edits are correct [3] [4] and that you are behaving nicely to other mathematical wikipedians [5] ? Mathsci (talk) 02:17, 10 September 2008 (UTC)

Can I just make the point that we have policies? And referring to them is not taboo. So "remove peacock term" is OK: it explains a removal by reference to policy. But, on the other hand, WP:COI must be handled with great care. Accusations that people are putting their own interests ahead of Wikipedia's are not to be bandied about. They, preferably, are taken up in a problem-solving manner, in reasonable discussions of what the content policies permit and encourage. So, edit summaries are too, well, summary for that. Charles Matthews (talk) 19:42, 10 September 2008 (UTC)

Exactly. Paul August ☎ 20:17, 10 September 2008 (UTC)

Come on, folks, most of us here are Ph.D.'s in mathematics or related sciences. Let's behave accordingly. Without singling anybody out, Mathsci and Arcfrk, could you please make more effort to keep respectful, cordial, and collegial? Inflammatory and disparaging comments are just going to create grief and stress, wasting tremendous amount of energy which could be used in a good way on improving articles.

Editing disputes are hard and frustrating, I've witnessed it first hand. But if, of all people, folks who are mathematicians and PhD's can't deal with disagreements on amicable terms, then I don't know who can. Oleg Alexandrov (talk) 06:11, 16 September 2008 (UTC)

Close-packing of spheres

User:Noodle snacks has moved close-packing to close-packing of spheres and then to close-packing of monodisperse spheres. If you have an opinion or comment about this move, please contribute to the post-move discussion at Talk:Close-packing of monodisperse spheres. Gandalf61 (talk) 10:57, 15 September 2008 (UTC)

Mathematical illustrators

Is there a list or category of editors who enjoy producing mathematical illustrations? I have very little artistic skill, but I can imagine there are people who would enjoy creating images from time to time.

I thought of this when I was looking at Real projective line. I think that an image of RP(1) as a circle, with the point at infinity at 12:00 and zero at 6:00, with a co-compact neighborhood of the point at infinity colored differently, would give the reader a nice sense of what's going on. But I don't have the skill to produce that sort of diagram myself. — Carl (CBM · talk) 13:28, 10 September 2008 (UTC)

There is Wikipedia:WikiProject Mathematics/Graphics, Wikipedia:Requested pictures. --Salix alba (talk) 14:51, 10 September 2008 (UTC)

Thanks, I didn't know about the graphics project. I'll ask them. — Carl (CBM · talk) 16:43, 10 September 2008 (UTC)

I gave it a try, see the article. I love making pictures (more than writing bot code :) so I'd be happy to make any picture if it is needed anywhere. Oleg Alexandrov (talk) 06:38, 16 September 2008 (UTC)

Thanks, a lot!. — Carl (CBM · talk) 11:40, 16 September 2008 (UTC)

Deletion discussion

I have proposed Non-Newtonian calculus for deletion. The discussion is at Wikipedia:Articles for deletion/Non-Newtonian calculus. Ozob (talk) 00:39, 13 September 2008 (UTC)

Current consensus is to keep. If you have a comment to make, there's still about a day before the discussion closes. Ozob (talk) 23:44, 16 September 2008 (UTC)

Convex metric space

Tosha keeps on redirecting the well-referenced article Convex metric space to Intrinsic metric without any edit summary, although these are different concepts (an annulus is not a convex metric space with the Euclidean distance, but the Euclidean metric is an intrinsic metric on this space). Comments? Oleg Alexandrov (talk) 19:35, 14 September 2008 (UTC)

The articles should probably discuss the relationship between the two concepts, and especially shouldn't just link to each other without explanation, given the similarity of the definitions and the fact that "convex space" can apparently refer to either. (Incidentally, having looked at the articles, I'm having trouble seeing how the Euclidean metric on an annulus can be intrinsic. Am I missing something?) —Ilmari Karonen (talk) 21:04, 14 September 2008 (UTC)

You're correct. The annulus degenerates to S¹, and the intrinsic metric article says that S¹ with the Euclidean metric is not intrinsically metrized. Ozob (talk) 22:42, 14 September 2008 (UTC)

Counterexamples exist, anyway. The rationals with the Euclidean metric are convex but not intrinsic, while the plane with an open line segment removed, equipped with the intrinsic metric induced by the Euclidean metric, is intrinsic but not convex. Algebraist 23:20, 14 September 2008 (UTC)

Erm, what are the paths connecting points near to, but on opposite sides of, the removed line segment? Geometry guy 22:33, 15 September 2008 (UTC)

They go round the end, in a couple of straight line segments. Since I've used the intrinsic metric induced by the Euclidean metric, rather than the Euclidean metric itself, the length of that path is equal to the distance between the points. Algebraist 22:52, 15 September 2008 (UTC)

Thanks! I misunderstood and thought you were saying the metric induced by the Euclidean metric (by restriction) was intrinsic. Geometry guy 12:23, 16 September 2008 (UTC)

deletion of abstract nonsense

Please comment at Wikipedia:Articles_for_deletion/Abstract_nonsense. Katzmik (talk) 12:21, 16 September 2008 (UTC)

Wikipedia talk:Mathematics Collaboration of the Month

There is a ongoing discussion how to inhale some more life into the COTM. Please have a look and (if you have some) tell your thoughts on how to improve the collaborative aspects of WPM. Jakob.scholbach (talk) 15:39, 16 September 2008 (UTC)

Wikipedia 0.7 articles have been selected for Mathematics

Wikipedia 0.7 is a collection of English Wikipedia articles due to be released on DVD, and available for free download, later this year. The Wikipedia:Version 1.0 Editorial Team has made an automated selection of articles for Version 0.7.

We would like to ask you to review the articles selected from this project. These were chosen from the articles with this project's talk page tag, based on the rated importance and quality. If there are any specific articles that should be removed, please let us know at Wikipedia talk:Version 0.7. You can also nominate additional articles for release, following the procedure at Wikipedia:Release Version Nominations.

A list of selected articles with cleanup tags, sorted by project, is available. The list is automatically updated each hour when it is loaded. Please try to fix any urgent problems in the selected articles. A team of copyeditors has agreed to help with copyediting requests, although you should try to fix simple issues on your own if possible.

We would also appreciate your help in identifying the version of each article that you think we should use, to help avoid vandalism or POV issues. These versions can be recorded at this project's subpage of User:SelectionBot/0.7. We are planning to release the selection for the holiday season, so we ask you to select the revisions before October 20. At that time, we will use an automatic process to identify which version of each article to release, if no version has been manually selected. Thanks! For the Wikipedia 1.0 Editorial team, SelectionBot 23:25, 15 September 2008 (UTC)

We're actually doing very well with cleanup tags. There are 729 math articles listed on the selection, of which only the ones listed below are on the list of articles with maintenance tags. The deadline for these is Oct 20, but it looks like we could clean them up sooner than that. — Carl (CBM · talk) 00:04, 16 September 2008 (UTC)

1. Action_(physics): cleanup
2. Alexander_Grothendieck: clarify
3. Applied_mathematics: cleanup
4. Arc_length: cleanup
5. Big_O_notation: cleanup
6. Central_limit_theorem: expert
7. Continued_fraction: cleanup
8. Convolution: clarify
9. Coordinate_system: cleanup
10. Exponential_growth: original research
11. Fourier_transform: clarify
12. Hilbert's_problems: original research
13. Hindu-Arabic_numeral_system: clarify
14. History_of_mathematics: cleanup
15. If_and_only_if: clarify
16. Infinity: original research
17. Information: cleanup
18. Isaac_Newton: cleanup · clarify
19. Linear_regression: cleanup
20. Logarithmic_scale: cleanup
21. Mandelbrot_set: cleanup
22. Momentum: clarify
23. Monty_Hall_problem: expert
24. Nash_equilibrium: cleanup
25. Parallel_postulate: expert
26. Philosophy_of_mathematics: original research · cleanup
27. Plane_(mathematics): expert
28. Polytope: clarify
29. Prime_number: clarify
30. Stochastic: cleanup
31. Student's_t-distribution: cleanup

Action (physics), infinity, and momentum are not mathematics articles. CRGreathouse (t | c) 04:13, 16 September 2008 (UTC)

I wouldn't say that, especially about infinity. It isn't solely a mathematics article, no, but large sections of it are about mathematics. We can't expect all articles to fall into neatly demarcated boxes; this one is clearly within our sphere of responsibility, even if not ours alone. --Trovatore (talk) 07:29, 16 September 2008 (UTC)

I tend to agree about the two physics articles. The reason they're on our list is because our project banner is on their talk pages. — Carl (CBM · talk) 11:43, 16 September 2008 (UTC)

The two articles are quite rightly on both the list of mathematics articles and the list of physics articles. It is a narrow conception of mathematics indeed that does not include concepts from classical mechanics, symplectic geometry and the calculus of variations such as Lagrangians and canonical conjugate coordinates!

I've struck off Monty Hall problem: it has had plenty of expert attention and there is currently no tag. Big O notation is a bit of a nightmare. Unless someone is courageous enough to tackle it, 0.7 may be better off without it. Geometry guy 12:09, 16 September 2008 (UTC)

The question, of course, is how narrow a conception of mathematics we should use... Historically we have used a very broad conception, especially in the List of mathematics articles, and to a smaller but still significant degree in talk page tagging. Of course, nobody is obligated to work on articles simply because they have a math tag. I tend to choose the articles that I will enjoy editing and leave the rest for other people.

The articles that are marked "expert" will often have the expert tag on their talk page. I commented out the tag from the Monty Hall problem article. — Carl (CBM · talk) 12:19, 16 September 2008 (UTC)

Thanks! I agree, and will do the same. The prospects for Big O notation don't look good... :-) Geometry guy 12:29, 16 September 2008 (UTC)

If it's still possible to omit chosen articles, the one I'd get rid of is if and only if. I cringe every time someone wikilinks that article; it's like wikilinking the word and. To be honest I wish we didn't have the article at all. --Trovatore (talk) 17:26, 16 September 2008 (UTC)

I'd also like to see the iff article go. Big O, though, is too important to leave off -- we should fix it up to whatever standard is required.

I still hold that Infinity is not a mathematical article. It focuses more on nonmathematical concepts (open/closed universe, IEEE, art, "Early Indian views" and other history, the lemniscate symbol) than the math. Further, the math section is in an amazing state of disarray.

CRGreathouse (t | c) 14:14, 18 September 2008 (UTC)

Yes iff should go. Paul August ☎ 17:06, 18 September 2008 (UTC)

I've deleted the "cleanup" tag from Student's t-distribution. It was put there on June 12th by an anonymous user who did not explain on the talk page why it was there. It looked at the article a bit today, admittedly not with a fine-toothed comb, and I couldn't see any evident reason why a "cleanup" tag should be there. Michael Hardy (talk) 01:35, 17 September 2008 (UTC)

Criteria for importance rankings?

Looking over the list of selected articles, I was surprised by many of the importance rankings. Perhaps it would be helpful to consider what our criteria are for assigning articles to Low, Mid, High and Top importance? For instance, the four color theorem, the Abel-Ruffini theorem and the Atiyah-Singer index theorem are all ranked as Top importance, which they very well may be (hi Reb! :). But then topics that seem more likely to be searched out by beginning students—such as point (geometry), area, volume, parallelogram, cylinder (geometry), tetrahedron, hyperbola, and parabola—are all of Mid importance. (Circle, triangle and sphere are of Top importance.) I'm not saying that we should rank importance by hitcount, but perhaps we ought to consider giving such basic topics greater importance and perhaps reserving the Top importance slot for entire fields and fundamental objects such as group (mathematics) and point (geometry)? More generally, what are our criteria for Importance? Should we go through the list of selected and nearly-selected articles to make sure that our rankings are internally consistent? Willow (talk) 12:31, 18 September 2008 (UTC)

Here are the present criteria for importance ratings. According to them, Top-importance articles are "must-haves" for any good general encyclopedia/lexicon/reference work or mathematical encyclopedia/lexicon/reference work, whereas High-importance articles are "very much needed, even vital", and Mid-importance articles are "not vital, but have some impact outside of field".

If we accept these criteria, then it seems as though we have a practical method for determining the importance ranking of an article. We can examine other general encyclopedias and mathematical reference works to see how often the topic (or a counterpart under a different name) occurs, and to what degree it is described. By that method, it would seem that "hyperbola" and "cylinder" are of Top importance and the "Abel-Ruffini theorem" is of Mid or Low importance. This suggests that we should review the Importance rankings of articles with, say, a score of greater than 1000, since that will materially affect the articles chosen to be included in Wikipedia 0.7 and, later, Wikipedia 1.0. Willow (talk) 16:24, 18 September 2008 (UTC)

Inframetric

While this new article cites a 2008 conference report, I have some doubts whether this can be regarded as an established concept in metric geometry, and I would welcome further comments at Talk:Inframetric. Regards, HaeB (talk) 03:44, 19 September 2008 (UTC)

"average radius"

In Semi-major axis, we can read "The average radius of an ellipse, measured with respect to its geometric centre, is ${\sqrt {ab}}=a{\sqrt[{4}]{1-e^{2}}}\,\!$."

Well, but ellipse never defined the "average radius". What is it? My best guess is "the radius of the circle of the same area". But is it really the definition? Barraki (talk) 18:07, 17 September 2008 (UTC)

It will be the radius averaged over something, probably angle but possibly arc length. If it's angle, then the average will be ${\frac {1}{2\pi }}\int _{0}^{2\pi }{\frac {ab}{\sqrt {a^{2}\sin ^{2}\theta +b^{2}\cos ^{2}\theta }}}\mathrm {d} \theta$. I don't know if that works out to ${\sqrt {ab}}$ or not - my calculus has never been great. --Tango (talk) 18:19, 17 September 2008 (UTC)

Oh, I tried this one with Maple: the result involves functions way more complicated than this. $b{\sqrt {\frac {{a}^{2}}{{b}^{2}}}}{\it {EllipticK}}\left({\sqrt {-{\frac {{a}^{2}-{b}^{2}}{{b}^{2}}}}}\right){\it {csgn}}\left(a\right)$. Insane. Barraki (talk) 18:40, 17 September 2008 (UTC)

Better math typesetting:

$b{\sqrt {\frac {a^{2}}{b^{2}}}}\operatorname {EllipticK} \left({\sqrt {-{\frac {a^{2}-b^{2}}{b^{2}}}}}\right)\operatorname {csgn} \left(a\right)$

Also, why do you write {a}^{2} {b}^{2} when a^2 b^2 will suffice? All the superfluous extra curly braces can make newbies think those are needed in such circumstances. Michael Hardy (talk) 19:01, 17 September 2008 (UTC)

As the article says, "The semi-major axis is the mean value of the smallest and largest distances from one focus to the points on the ellipse.". In terms of an orbit around a celestial body, it is the average of the distances from the body to the periapsis and the apoapsis. JRSpriggs (talk) 20:27, 17 September 2008 (UTC)

If we're talking about a celestial body, I'd expect it to be a time average, taking into account the fact that the body moves faster at one end of the major axis than at the other. But in geometry, I expect either an angle average or an arc-length average or something symmetric like that. Michael Hardy (talk) 21:10, 17 September 2008 (UTC)

Well, sorry for the silly TeX, I copy-pasted it from Maple TeX generator.

What bothers me is that the sentence "The average radius of an ellipse, measured with respect to its geometric centre, is..." sounds like there is a property in ellipse called the average radius.

The semi-major axis is also the time average distance from Sun, for a light planet. Sun is of course not on the center, but on the focus. Here the sentence defines a radius from the center.

So, should we remove this sentence, because average radius of an ellipse is not defined in geometry ? Or just replace it with "the radius of the circle of same area" ? Barraki (talk) 21:32, 17 September 2008 (UTC)

Well, there is such a thing as the radius averaged with respect to angle, and there is such a thing as the radius averaged with respect to arc-length. I don't know which was intendend here, and it's not impossible that it was some other. Michael Hardy (talk) 23:56, 18 September 2008 (UTC)

It's written "measured with respect to its geometric centre". I think this information is useless if you average with respect to arc-length. Well, after some searches, I conclude I can replace it with "equivalent average radius i.e. radius of the circle of the same area". I found this definition here, for example. [6] Barraki (talk) 12:06, 19 September 2008 (UTC)

Move of set to set (mathematical)

Please comment at talk:set (mathematical)#Move. --Trovatore (talk) 22:37, 17 September 2008 (UTC)

I heard somewhere that wikt:set is the word in the Oxford English Dictionary which has the most possible meaning, I seem to recall it was in the thousands. --Salix alba (talk) 23:19, 17 September 2008 (UTC)

OED's two head entries for the noun "set" give nearly 100 meanings. That doesn't include "set" the verb or participle. I'm sure we'll all be pleased to have another look at set, n.2, II.10.c: "Math. and Logic. An assemblage of distinct entities, either individually specified or which satisfy certain specified conditions. Cf. ELEMENT n. 5d." Ozob (talk) 01:03, 18 September 2008 (UTC)

If it is decided to leave the article at Set (mathematics) where it currently is, then we need an administrator to move Set (disambiguation) to the redirect Set because that has a non-trivial history now. JRSpriggs (talk) 15:13, 19 September 2008 (UTC)

Done.--Salix alba (talk) 17:45, 19 September 2008 (UTC)

Mathematics timelines

It seemed difficult to me, with the existing Timeline of mathematics, to trace the development of any particular field of mathematics.

So, without touching that article, I've tried to split out its contents to be the starting point on new timeline articles for particular themes and fields:

• Timeline of numerals and arithmetic
• Timeline of algebra and geometry
• Timeline of calculus and mathematical analysis
• Timeline of number theory
• Timeline of mathematical logic
• Timeline of probability and statistics

It's only a first stab, and probably needs some tweaking. Certainly some of the timelines look to me as if they have some quite important things missing: indeed, some which should also perhaps be added to the central times. This exploding out of the central timeline I hope may make that easier to spot.

Also, I was only quickly cutting and pasting, so its likely I may have put some things in the wrong list. Or perhaps we also need to discuss where to most usefully draw list boundaries.

There are also existing timelines: Timeline of algorithms, Timeline of classical mechanics, and Algebra Timeline. The last I only spotted when I'd already made a Timeline of algebra and geometry from the central timeline, so perhaps people can comment what they think is the best way forward on that. I think there's an unmet need for a more comprehensive algebra timeline than either of the now two existing ones, particularly covering the sequence of developments in the 19th century in more detail; but that seems so wrapped up together with geometry, I thought maybe best not to split the two.

Anyway, here they are, offered as a starting point. Jheald (talk) 17:38, 18 September 2008 (UTC)

Or alternatively, are they of no value and should be culled? Jheald (talk) 17:49, 18 September 2008 (UTC)

It's nice that you are working on that, but I think it might be an idea to include these information into history of arithmetic, for example, or the history section of arithmetic instead. Having such list-style articles is, I feel, not as good as having a true prose article, which can also explain a bit the transition processes etc. (which is not really possible in a list environment). Jakob.scholbach (talk) 09:23, 19 September 2008 (UTC)

Proposed move

I noticed an edit in which someone changed a link to construction of the real numbers to a link to construction of real numbers, with no "the". The title with the definite article is a redirect. Omitting "the" seems weird. It is as if individual real numbers were to be constructed, rather than the system as a whole. Are there opinions on moving the page to construction of the real numbers? Michael Hardy (talk) 18:58, 18 September 2008 (UTC)

I agree with you. -- Dominus (talk) 19:16, 18 September 2008 (UTC)

Yes, without "the" it looks like we are not sure all real numbers can be constructed. Barraki (talk) 22:36, 18 September 2008 (UTC)

True, but it can also be read as construction of "real numbers", it being understood that everybody has heard of the famous "real numbers". It can also be read as an editorial contraction, headline-style. I think this should be a question of wiki style guidelines rather than a semantic issue. Katzmik (talk) 05:32, 19 September 2008 (UTC)

People seem to think that wikipedia naming conventions mean omiting articles ("a", "the" etc.) from titles. That's only true at the beginning of the title. Compare e.g. Capital punishment in the United States. It would be absurd to omit the "the" here, even though it is purely semantic. Geometry guy 09:38, 19 September 2008 (UTC)

I also agree, and have moved it. Algebraist 12:43, 19 September 2008 (UTC)

"Geometry guy", what does the phrase "purely semantic" mean? Semantics is the study of meaning, so "it is purely semantic" must mean that it only conveys some meaning. Is that what you meant? Michael Hardy (talk) 15:57, 19 September 2008 (UTC)

Often when someone is accused of arguing purely on semantics, it means the person is more interested in being technically correct rather than conveying meaningful information. This is somewhat at odds with the definition of semantics as the study of meaning. But you can see how the use of "purely semantic" may have arose. Even when everybody understands something, there may be some person interested in being "technically correct". In that context, "purely semantic" means that though no meaningful point is being made, some technical point is being made. To interpret G-Guy's use of the phrase, what he means is that as far as meaning goes, everyone understands what is meant. Nobody is going to get confused over the lack of "the" in front of "united States". Nonetheless, G-Guy thinks the lack of "the" is ridiculous in that example, despite the difference being "purely semantic". --C S (talk) 16:21, 19 September 2008 (UTC)

Yes I really meant "purely syntactic" (!), but thanks to C S for explaining this all-too-common abuse of language... Geometry guy 17:54, 19 September 2008 (UTC)

Identically distributed

There is a redirect from Identically distributed to Random variable. This seems like the wrong thing to do to me, particularly since the article no where uses the phrase identically distributed. There is a page (maybe just a stub?) Independent_and_identically-distributed_random_variables which would be more appropriate, but I am not sure how to change redirects. Thenub314 (talk) 10:06, 19 September 2008 (UTC)

I've changed it. For future reference, you just edit redirects like any other page - if you click the "redirected from" link at the top you'll get taken to the actual article without it following the redirect and can click "edit this page" as usual. --Tango (talk) 10:52, 19 September 2008 (UTC)

Good to know. Thanks! Thenub314 (talk) 13:00, 19 September 2008 (UTC)

Tessarine non-admin closure of deletion discussion was premature

Please comment at the review page. Katzmik (talk) 08:58, 16 September 2008 (UTC)

Um, there doesn't seem to be a section for it. Are you sure you completed the nomination? But really I'd invite you to rethink it -- "interrupted discussion" is not really a reason not to close, and it was clear that no one besides (possibly) the nominator was supporting deletion. Any other disposition suggested, such as "merge", is actually a form of "keep", and therefore leaves no issue for AfD; this can all be handled on the talk page. --Trovatore (talk) 09:13, 16 September 2008 (UTC)

Well, I followed the instructions and placed the appropriate widget at the beginning of the article itself. Katzmik (talk) 09:20, 16 September 2008 (UTC)

There are four steps listed at Wikipedia:Deletion review#Steps to list a new deletion review. I think you've only done step 1. But really I'd reconsider. Maybe you interpreted the closure as saying a merge is now not permitted, but I don't think that's true; it just means that the article will not be deleted. You could even boldly redirect it somewhere without merging any content, and that's still not deletion; while it might be frowned on at this point if you did it without discussion, the discussion doesn't have to happen at AfD, which is about deletion. I don't think there are any serious issues to raise at DRV. --Trovatore (talk) 09:38, 16 September 2008 (UTC)

The "Keep" looks to have been entirely appropriate to me, and the discussion appropriately conducted. I don't think you've got a leg to stand on. Jheald (talk) 09:37, 16 September 2008 (UTC)

Agree with Jheald. Also, when referring to deletion discussions, please supply a link: Wikipedia:Articles_for_deletion/Tessarine. Geometry guy 10:08, 16 September 2008 (UTC)

Yes the keep close was appropriate at that time. There may be a case for merging the article into History of Quaternions, but that option came up too late in the discussion to get a good hearing. A discussion on merging does not need a full AfD or a deletion review and can be carried out on the talk page of the article. --Salix alba (talk) 13:06, 16 September 2008 (UTC)

Well, I think this kind of keep sets the wrong kind of precedent, but I don't feel strongly enough to pursue this in a quixotic fashion. It is very easy to score brownie points with fellow editors by consistently voting keep, but how is one to weed out walled-garden pages? Katzmik (talk) 13:29, 16 September 2008 (UTC)

There is a difference between disagreeing with the community decision and disagreeing with the closure. Deletion Review is for when you disagree with the closure, that is you think the community actually decided something different from what the person closing the AFD put. In this case the community clearly decided to keep the article, so DR is inappropriate. If you want to delete the article, you'll need to go through AFD again, not DR. I suggest waiting a month or so at least, otherwise people won't even consider it, even then I doubt you're likely to change people's minds. --Tango (talk) 13:04, 18 September 2008 (UTC)

Please re-read my previous comment. Katzmik (talk) 13:14, 18 September 2008 (UTC)

I don't think it's helpful to do so. We get that you don't like the outcome (I don't care either way). Tango's explanation is correct. Deletion review is for when you think the deletion procedure was mishandled, not when you don't like the way it resulted. As for the "walled-garden" syndrome, that's something that's been part of Wikipedia for a long time. The deletion policy is very lenient on what constitutes keep or no consensus; that among other reasons is why something like the BLP policy had to be enacted, and since I don't think you were around for that, let me say you'd be surprised at what an uproar that caused ("What? You can't delete my biography about a slightly notable stamp collector/businessman which contains a scattering of minor local newspaper references alleging child molestation!") There are numerous cranky articles on Wikipedia. One that comes to mind is Illegal_number, where I basically destroyed any argument in favor of it on the talk page. But I doubt it will be deleted any time soon. At least with tessarine we have actual real references and citations. --C S (talk) 19:02, 20 September 2008 (UTC)

TeXnical issue

Apparently it's the fact that the letter p goes below the line that causes the subscript under "sup" to be lower than that under "inf". But it seems to me that in this case one ought to prefer them to be at equal levels. Is this a flaw in TeX's perfection?

$\inf _{n\geq 0}\,\sup _{m\geq n}x_{m}\,$

Michael Hardy (talk) 01:24, 17 September 2008 (UTC)

In TeX I would use this syntax:

\mathop{\rm inf\vphantom{p}}_{m<n} \mathop{\rm sup}_{m < n}

but this does not work in Mediawiki's texvc. I don't know how to achieve this effect in texvc. — Carl (CBM · talk) 01:48, 17 September 2008 (UTC)

Corrected my typo - this needs to use vphantom instead of phantom to avoid extra horizontal space. — Carl (CBM · talk) 22:11, 20 September 2008 (UTC)

Knuth discusses it in the TeXBook, I think, and of course considers this sensitivity to letter depth a feature (naturally, he proposes a workaround for when it is not a feature, probably the one Carl did). However, considering the extent of our handicap in typesetting here, I think this is not something we can reasonably expect to fix: altering this behavior is essentially the definition of the \phantom command, and since we don't have that, by definition we can't make the change. There is one other command, \raisebox, available in LaTeX normally but, of course, not here, that would also work (as it does much the same thing) were it not for this abridgement. None of the other spacing commands produces vertical space within a line, and besides, all the vertical space functions are unrecognized because we don't produce multiline documents here. Ryan Reich (talk) 02:47, 17 September 2008 (UTC)

Jitse's bot

Does Jitse's bot function only when Jitse Niesen is around? At Wikipedia:WikiProject Mathematics/Current activity we observe that no new math articles have been created, nor any added to AfD, etc., etc., for more than five days. Is there no one who can arouse the bot from its coma while Jitse is on vacation? Michael Hardy (talk) 16:35, 19 September 2008 (UTC)

An interesting view of priorities! :-) I would say that when Jitse is too busy for Wikipedia, he is definitely not on vacation....--C S (talk) 18:47, 20 September 2008 (UTC)

Manifold Destiny proposed for deletion

Claimed BLP violation(s) and WP:COATRACK. VG ☎ 22:52, 20 September 2008 (UTC)

List of Cambridge mathematicians

I would like to make a major edit to the list. I propose making a table, as in here. (feel free to edit my draft!) Randomblue (talk) 12:03, 15 September 2008 (UTC)

Looks good to me. I would not have a column for each of the different chairs, probably just a single Chairs column. I'd probably also have class="wikitable" in the table def as it look better than html table format. See Help:Table. --Salix alba (talk) 12:27, 15 September 2008 (UTC)

Thanks Salix, I've made just a single "Chairs" column. Is there a way of using the class "wikitable" without changing the way the data is inputed? Randomblue (talk) 15:41, 15 September 2008 (UTC)

I've changed the tables to be sortable. To let people get back to the original ordering, you might like to make the names {surname, forename}, or add a sequence number column to the left. Jheald (talk) 21:27, 15 September 2008 (UTC)

Good idea, thanks Jheald. Randomblue (talk) 21:52, 15 September 2008 (UTC)

"Studied at" would be useful. Also, "head" or "head of house" is the general term. Richard Pinch (talk) 22:22, 15 September 2008 (UTC)

This could get quite long: see for example Category:Senior wranglers and Category:Second wranglers. Richard Pinch (talk) 22:27, 15 September 2008 (UTC)

Ok for the new columns. Yes, it will be relatively long. Maybe some sort of break down would be useful. What about a page for every century? Randomblue (talk) 22:55, 15 September 2008 (UTC)

Sadly the list specification is too vague. Charles Matthews (talk) 21:00, 21 September 2008 (UTC)

Algebra timeline

Someone moved Timeline of algebra to Algebra Timeline, with the incorrectly capitalized initial T. I moved it to Algebra timeline with lower-case t. Before fixing all the double redirects, maybe we should consider whether the first page move makes any sense. Michael Hardy (talk) 05:27, 21 September 2008 (UTC)

I prefer "Timeline of algebra". CRGreathouse (t | c) 21:17, 21 September 2008 (UTC)

I support Michael Hardy's move back to Timeline of algebra like most "Timeline of ..." articles. The user posted to Wikipedia:Help desk/Archives/2008 September 17#Rename article but ignored most of the advice and gave a confusing argument about being in its own category. Maybe it referred to being alphabetized under Algebra in categories but a sort key [7] is a better way to achieve that. PrimeHunter (talk) 01:04, 22 September 2008 (UTC)

Piergiorgio Odifreddi's bio

I've flagged it with {{POV}} because it seems to focus too much on controversies, lawsuits etc. If somebody knows more about Odifreddi's bio, please have look at the article. To me he's best know for his books on recursion theory, but I probably have a narrow perspective. VG ☎ 21:46, 21 September 2008 (UTC)

I've removed the offending sentences. Geometry guy 22:11, 21 September 2008 (UTC)

Theory of continuous composition

Somebody added a link to Function composition pointing to an article about the "Theory of continuous composition" hosted on on another wiki. I've not heard of "continuous composition" before, the linked article seems unpublished stuff that didn't make much sense to me, so I've reversed the addition. VG ☎ 23:29, 21 September 2008 (UTC)

>>I apologize, what you say is correct. My article is about my own work. MandelZoom in sourceforge is a little demostration applied to MandelBrot fractal to see soft colour field due to real composition, but that's original stuff and after reading the wiki policy, I have understand that's wrong to include here. Thanks. —Preceding unsigned comment added by 80.25.164.213 (talk) 14:26, 22 September 2008 (UTC)

Userbox?

Hi, I have just recently joined this WikiProject. I was wondering if we already had a userbox for this project or if I should create a new one. Thanks, feel free to reply on my talk page. --electricRush (talk) 01:51, 23 September 2008 (UTC)

{{User WikiProject Mathematics}}. PrimeHunter (talk) 01:56, 23 September 2008 (UTC)

Thanks! --electricRush (talk) 02:07, 23 September 2008 (UTC)

Problem of Apollonius for FAC

Problem of Apollonius, a geometry article written by WillowW is up for FAC, here. Jakob.scholbach (talk) 15:41, 23 September 2008 (UTC)

Minimum distance estimation

Perhaps I'm just missing something, but do we have an article on minimum distance estimation? -- Avi (talk) 20:46, 23 September 2008 (UTC)

Maybe this is irrelevant, but maybe try the distance formula? --electricRush (T) (C) 01:08, 24 September 2008 (UTC)

I do think that's irrelevant in this case. Michael Hardy (talk) 01:22, 24 September 2008 (UTC)

Maybe we don't have one. You might want to bring this up at Wikipedia talk:WikiProject Statistics. Michael Hardy (talk) 01:22, 24 September 2008 (UTC)

Done, thank you. -- Avi (talk) 02:49, 24 September 2008 (UTC)

Vector (geometric)

There is a RM to make the dab (directd quantity). This rubs me the wrong way; it seems to me that most of the fumbling at vectors since Hamilton has been caused by this contradiction in terms.

But do come and discuss it; you may convince me. Septentrionalis PMAnderson 04:27, 24 September 2008 (UTC)

Is "Actuary" a mathematics article?

Avraham (talk · contribs) just added Actuary to our list of featured articles, on the grounds that it has been a featured article since June 30, 2006 and it is a mathematics article (it has our template). But I question whether it is really about mathematics. Yes, actuaries use a lot of mathematics, but so do many other professions. There is no significant mathematics in the article. So I think that we should remove our template and remove Category:Mathematical science occupations from the list of mathematics categories. JRSpriggs (talk) 05:57, 24 September 2008 (UTC)

I disagree. Obviously, the key issue isn't the amount or kind of mathematics used, but the social divisions that exist, e.g. physicists or economists are not mathematicians although the boundaries can get blurred. Actuarial science has a lot more to do with the academic establishment of mathematics than many other math-related disciplines. A common place to get an actuarial degree is from a math or stats department e.g. [8] or [9]), and many actuaries have a math or stats graduate degree background. --C S (talk) 06:21, 24 September 2008 (UTC)

Bad template

template:math fails to provide proper spacing in expressions like 4 ≥ 3. I therefore expunged the template from an article, Dirichlet's energy, I just edited. I will do likewise with other articles in which I find it if this flaw persists. Michael Hardy (talk) 06:24, 25 September 2008 (UTC)

Spaceing seems fine to me with template: E[u] ≥ 0 handcoded: E[u] ≥ 0. All it does change the CSS style to match that of the <math> tag, which has the effect of using a serif font. Spacing will match that of the new font, which may not have the same point size as a san-serif font. This is set by the browser preference.

I've found quite a few templates for formatting inline equations and collected them in Category:Mathematical formatting templates and nominated one {{Nth}} for deletion. Some of these seem decidedly dodgy.--Salix (talk): 07:16, 25 September 2008 (UTC)

We might actually want to fix the template instead of just removing it from article. Playing around with the css properties "letter-spacing" and "word-spacing" should let us get the desired result. (may be even better then obtainable through normal formatting.) While we're at it we should probably also add "white-space:nowrap", making the use of   unnecessary.

(note that the template only gets used in a handfull of pages of which only a few are in the article name space. So changing the tempate shouldn't break to much and that what is broken should be easy to fix. (TimothyRias (talk) 08:54, 25 September 2008 (UTC))

The template itself is not the place to do this. Possible in MediaWiki:Common.css, but test in Special:Mypage/monobook.css first. Applying the serif font happens in a non-wiki page [10]. Care needed as the template also affects <math> tag when its rendered in html. So <math>E[u]>0</math> is formatted using the same css style: $E[u]>0$.--Salix (talk): 09:27, 25 September 2008 (UTC)

I had a look at what the template actually does, which is actually very little. It simply adds a span with class="texhtml". This class is currently way under defined in the standard wikipedia monobook (or rather the shared.css), it only adds a serif font and nothing else. This should probably be fixed. (the texhtml is actual the class applied to html generated by <math>, which currently will allow line breaks in the center of equations.)

Unfortantely, any change made to this class has to be done with care because it could break a million articles if done wrong. Still, I think a push should be made to actual have the texhtml class reproduce standard tex math mode behavior.

To summerize, it is not the template that is broken it is just the texhtml class that is bad. (TimothyRias (talk) 09:18, 25 September 2008 (UTC))

Merge Subnet_(mathematics) with Net_(mathematics)?

I have been working on the General Topology articles off and on for some time now. I just noticed that the main article Net_(mathematics) on net convergence in topology does not in itself define "subnet", but rather there is a separate article Subnet_(mathematics). It would seem natural to me to move the material from the latter article into the former article. What do others think? Plclark (talk) 07:25, 25 September 2008 (UTC)

Good idea. Richard Pinch (talk) 08:04, 25 September 2008 (UTC)

E8 investigation tool

This article, which is proposed for deletion here, seems to have a couple of links that would be okay as external links in E₈. Someone more familiar with this topic should perhaps take a look at it before it's axed. VG ☎ 15:23, 25 September 2008 (UTC)

Perhaps it could be merged into An Exceptionally Simple Theory of Everything which seems to be about the same thing. JRSpriggs (talk) 17:57, 25 September 2008 (UTC)

There's no useful content to merge: the two links are already at An Exceptionally Simple Theory of Everything and the rest is unsourceable opinion and OR. Geometry guy 18:03, 25 September 2008 (UTC)

Notability and Director strings

A discussion (so far, very short) has been started on WP:NOTABILITY regarding an article I recently created. I am skittish about that forum, having been burned too many times by the non-science-oriented Wikipedia editors. I have urged that the discussion there be moved to here, as, here, we have both the domain experts, and the general cultural orientation, to deal with such things. If, for any reason, this starts turning into a large discussion, I would further like to move the debate to where the Physics, Comp Sci, and Biology communities can contribute, as these sorts of policy debates can, and do, have impact on all. linas (talk) 03:24, 26 September 2008 (UTC)

I think your prior experience is making you overly-defensive about this whole thing, which is not good. Also, asking people to move discussions to specialized forums just make it seem like there's some cabal of science editors (I was surprised to see a well-known admin start making these accusations a while ago when CBM asked him to consult relevant content experts about future AFDs).

Articles sourced to several peer=reviewed papers with a decent amount of citations are never AFD-able. I'm sure the NOTABILITY people know that. In this case, it seems like you ran into a fairly inexperienced editor on the director string talk page. There's no need to sound the alarms. In any case, I've never had any problems raised by writing papers about well-sourced recent concepts. For computer science type things, you might need a few more sources than a purely math concept that is published in a well-established journal, but I really doubt people familiar with the notability guideline would try to delete or urge deletion of a concept with even a handful of sources. In fact, people have generally fought back against that when science-minded editors try to delete some crank idea.

One last comment. Director string credits a 2003 paper by three authors, but I find the concept is due to a 1988 paper by two other authors with 34 citations on Google Scholar (one of the citations is the 2003 paper). So it seems the concept is older and more established than you thought, which more or less renders the point moot. --C S (talk) 07:11, 26 September 2008 (UTC)

Meanwhile, Wikipedia:Notability/RFC:compromise seems relevant to the question of notability in specialist areas. Richard Pinch (talk) 07:15, 26 September 2008 (UTC)

It would probably be better to use Talk:Director string for the discussion, and just announce it here. That takes a little load off this board, and it also reduces and concerns (misplaced or not) about cabalism. — Carl (CBM · talk) 13:31, 26 September 2008 (UTC)

Oh noes, another war of notations

Curly vs. straight at Talk:Binary_relation#Symbols_for_Binary_Relations. VG ☎ 16:45, 26 September 2008 (UTC)

Category:Numerical integration and Category:Mathematical components on CfD

Category:Numerical integration is being proposed to moved Category:Numerical quadrature at CfD 16/9 and Category:Mathematical components is proposed to delete at CfD 24/9. Comments welcome. --Salix (talk): 17:00, 26 September 2008 (UTC)

Making mathematics articles more accessible to a general readership

Please visit Wikipedia:Village pump (proposals)#Easy as pi? to see a discussion about making mathematics articles more accessible to a general readership.
-- Wavelength (talk) 16:15, 26 September 2008 (UTC)

I've looked at the discussion which is rather unwieldy. Is there a specific proposal, if so could you clarify it on the VP page. On the general subject it is something we are well aware of and we do take seriously and strive towards, although it is a huge task. --Salix (talk): 16:39, 26 September 2008 (UTC)

Wavelength, if you wonder why there has been no response in the last ten days, have a look at WP:TLDR. It may not apply literally here, but the principle fits. --Hans Adler (talk) 17:35, 26 September 2008 (UTC)

Thank you both for your comments. I have added sub-subheadings, including some which indicate the presence of proposals. Some sub-subsections are still long, because I decided not to split any post into more than one sub-subsection. Generally, the very long posts were made my me, and I probably would have separated them into smaller posts at that time, if I had anticipated that I would be adding sub-subheadings. I named one subsection "Subsection 0" for consistency with the other numbered subsections. There is already a link to "Subsection 5" from Talk:Mathematics; otherwise, I would probably rename the numbered subsections by increasing each number by one.

-- Wavelength (talk) 02:26, 27 September 2008 (UTC)

(In the second last sentence of my previous message, I corrected "sub-subsections" to "subsections".)

-- Wavelength (talk) 13:00, 27 September 2008 (UTC)

Just so the project people know, one of the proposals in question would mandate lots of silly little boxes saying things like "A knowledge of calculus would be helpful in understanding this article/section/formula." Since the merits and demerits of this have been discussed here before, those of you with strong feelings on the matter may want to make your opinion known at that thread. siℓℓy rabbit (talk) 14:06, 27 September 2008 (UTC)

Or better still, keep quiet rather than revive the proposal. --Hans Adler (talk) 14:11, 27 September 2008 (UTC)

The discussion has been archived at Wikipedia:Village pump (proposals)/Archive 35#Easy as pi?.
-- Wavelength (talk) 15:17, 28 September 2008 (UTC)

Dimensional space

Can anyone make any sense out of the article titled Dimensional space? The first sentence is at best very vague, and the proposed example in the second (which is the last) sentence makes me suspect it may be just nonsense. Michael Hardy (talk) 00:39, 27 September 2008 (UTC)

Seems to be the only thing making non-Newtonian calculus non-trivial. It obviously makes sense, but whether it's interesting or has a serious application is open. — Arthur Rubin (talk) 00:48, 27 September 2008 (UTC)

The way to make sense out of it is the usual one - reliable sources. Richard Pinch (talk) 06:55, 27 September 2008 (UTC)

Yes, I wrote that page poorly, I've now redirected that page to dimensional analysis although the latter needs to be expanded to include use of dimensional analysis in mathematics, statistics,operations research, fractals, dimension theory and dynamical systems. Delaszk (talk) 10:35, 27 September 2008 (UTC)

Notability of individual papers

I was thinking of creating articles for a few of Emile Lemoine's best-known papers, when I realised that I wasn't entirely sure whether they warranted articles. The notability guideline is as vague as can be about this, and I don't really know how to judge a paper's notability. Something such as Ars Magna clearly deserves an article, while I'm sure we can all think of works that do not. The papers, however, which I'm specifically asking about are Sur quelques propriétés d'un point remarquable du triangle and La Géométrographie ou l'art des constructions géométriques. Anyone's thoughts? Nousernamesleft (talk) 18:58, 27 September 2008 (UTC)\

Have a look through Category:Mathematics literature which should give you some idea. --Salix (talk): 20:09, 27 September 2008 (UTC)

I can certainly find works which I would deem less important in there, such as Formulario mathematico, so I think I'll go ahead and write the articles. Nousernamesleft (talk) 20:52, 27 September 2008 (UTC)

Actually, whoops, I missed the importance of that work - it's a lot more important than the articles I'm suggesting. I'll keep searching. Nousernamesleft (talk) 20:54, 27 September 2008 (UTC)

János Bolyai, Non-Euclidean Geometry, and the Nature of Space is a work I would deem less important, so I'll go ahead and write them, then. I can't find any comparable works, however (i.e. by a lesser-known mathematician containing some fairly novel new work, but nothing groundbreaking). Nousernamesleft (talk) 20:58, 27 September 2008 (UTC)

The mere fact that a paper may qualify as a reliable source which could be cited in one of our articles is not sufficient to justify writing an article specifically about that paper (rather than the topic it is about). However, if there are books or other scholarly papers (history of science, philosophy of science, biography) written about that paper, then the paper itself (as opposed to its subject matter) qualifies as notable and may have an article about it here. JRSpriggs (talk) 00:33, 28 September 2008 (UTC)

I agree with JRSpriggs here. There are many publications that are fine as sources (even well-known in the field) but not themselves the subject of much commentary. We have to avoid the "other stuff exists" rationale; I'm sure that we already have some articles on non-important papers, because of the sheer number of editors and ability to create articles at whim. I think that some factors to consider include whether the paper is discussed in books on the history of mathematics and whether the paper appears in anthologies of classic papers. Here's another example to add to the list: On Formally Undecidable Propositions of Principia Mathematica and Related Systems. — Carl (CBM · talk) 14:29, 28 September 2008 (UTC)

Advice taken. I'll see how much I can write on either paper before making a final judgment on whether to create the articles. Nousernamesleft (talk) 02:10, 29 September 2008 (UTC)

Prime_Numbers_-_Binary proposed for deletion

Most !votes decided deletion. Perhaps there's some salvageable material to be merged into prime number. VG ☎ 18:51, 28 September 2008 (UTC)

Gen Rel Intro

Introduction to general relativity has been nominated for a featured article review. Articles are typically reviewed for two weeks. Please leave your comments and help us to return the article to featured quality. If concerns are not addressed during the review period, articles are moved onto the Featured Article Removal Candidates list for a further period, where editors may declare "Keep" or "Remove" the article from featured status. The instructions for the review process are here. Reviewers' concerns are here.