Wikipedia talk:WikiProject Mathematics/Archive/2014/Mar

"Numerical cipher"

A recently created redirect, Numerical cipher (edit | talk | history | protect | delete | links | watch | logs | views), currently points to Bifid cipher, is this correct? -- 70.50.151.11 (talk) 10:15, 23 February 2014 (UTC)

As far as I know, numerical ciphers are just ciphers that translate a message into a sequence of numbers. So Bifid cipher isn't equivalent. The redirect may have come from Numerical_cipher in the cryptography wikia. --Mark viking (talk) 13:33, 23 February 2014 (UTC)

I wouldn't trust anything coming from Wikia. What should we do with this redirect then? -- 70.50.151.11 (talk) 04:02, 24 February 2014 (UTC)

I've nominated it for deletion -- 70.50.151.11 (talk) 08:05, 27 February 2014 (UTC)

I've proposed at WP:RFD#Numerical_cipher that this be changed to redirect to Cipher (disambiguation). As far as I understand it, the use of the word cipher was common in the 16th and 17th centuries to mean zero, and often spelt cypher before English spelling got standardised (if we can call it that) in the late 18th to mid 19th centuries. I think it is perfectly reasonable to have it as a DAB (doesn't Isaac Newton in his Principia Mathematica on the differential and integral calculus calling the cheat of dividing by zero "the cypher"? Or was it John Napier doing logarithms? I forget which and most of my books are in store so can't check it from RS, and obviously Wikipedia is not in itself an RS so there's no point looking up what Wikipedia says about it. Si Trew (talk) 14:09, 1 March 2014 (UTC)

Catching up on accessibility issues/debate?

I have never edited or looked at a talk page of any Math article. I haven't even browsed the archives of this page yet. I am a naive and innocent passerby. A simple user who happens to have an editor account from other interests. I see the FAQ above and I know my questions and opinions are familiar and well-worn territory. However the FAQ doesn't sate my curiosity. Is there perhaps a famous thread or talk page or external blog post or something that really digs into the issue of accessibility of math articles?

My own feeling isn't about a specific article, but it can be summed up by my own behavior: if I'm searching on google for most topics and I see a result from wikipedia, I'm happy and always check it out, and often that is the end of the search. If I'm searching for something Math related and I see a wikipedia result, my first reaction is to avoid clicking on it, and if I click on it I'm _always_ disappointed by what I read. I _always_ have to keep digging for an alternate explanation. Why this is exactly is a bigger topic, but I wanted to just get some pointers first before I trot out the same old complaints. Silas Ropac (talk) 01:30, 25 February 2014 (UTC)

Here are some recent thoughts on this subject.

Wikipedia_talk:WikiProject_Mathematics/Archive/2013/Nov#A_couple_general_ideas

Wikipedia_talk:WikiProject_Mathematics/Archive/2013/Jun#Linear_function.2C_Linear_Equation.2C_Linear_Inequality_full_of_errors_and_inconsistencies_and_.22matheese.22

Wikipedia_talk:WikiProject_Mathematics/Archive/2013/Jun#A_wild_idea:_multi-tiered_maths_articles_to_match_the_target_audience.3F

Wikipedia_talk:WikiProject_Mathematics/Archive/2013/Feb#Linearly_ordering_the_mathematics_articles

I, too, have thoughts on why this is a perennial issue, but I'll save those for another time. Ozob (talk) 01:45, 25 February 2014 (UTC)

I think Wikipedia is more successful in its coverage of mathematics than in any other subject. (Nonetheless, I think there are vast areas of imperfection in Wikipedia's coverage of mathematics.) Michael Hardy (talk) 06:32, 25 February 2014 (UTC)

I think there is a middle territory between the elementary and the advanced that we don't generally do very well. In my own experience, areas like differential equations, special functions and to some extent linear algebra seem to be very incomplete and not well-done. Sławomir Biały (talk) 12:24, 25 February 2014 (UTC)

This has been said many times before, here and elsewhere, but the fundamental problem is that "math cannot be explained". In mathematics, you have to put real efforts to understand a concept you didn't know before. Wikipedia does not/is not meant to solve this. For example, I've always thought the definition of spectral sequence is very dry; the concept made sense "only after" doing concrete computations with simple and not so simple examples. Our spectral sequence is, not surprising, dry and didn't help much when I was learning the subject. (Coincidentally, if I were writing it, I would stress the exact couple of a filtered complex). -- Taku (talk) 14:03, 26 February 2014 (UTC)

"I think Wikipedia is more successful in its coverage of mathematics than in any other subject." Has there ever been an objective poll done by the wikimedia foundation or someone external? Comparing satisfaction on various subjects? I'm not asserting that I'm right or you're wrong, but just wondering if there is any objective data out there? Particularly that focuses on users and not editors.

However I guess I have to back pedal some. As I click through many dozen Math articles I see a much tamer situation than I had in my head. In my head based on math articles viewed over the last few years, and some recent clunkers, I was concluding that the math articles were allowing and encouraging the content to simply be pretty much all equations. That a pile of equations was seen as a reasonable explanation for any math concept.

While I feel there are various levels of domain knowledge required to understand articles throughout wikipedia, equations are a special case because they are essentially another language. It's as frustrating as if you looked up an article on Chinese literature, in the English wikipedia, and found a wall of Chinese characters. And then on the Talk page you read the editors insisting "only Chinese can adequately explain Chinese literature". That clearly would not fly.

However I'm not really seeing that as an endemic problem here. I do see tons of equations, but I'm assuming math people expect and require that. But I also see lots of attempts to explains things with words. I think when I see an article that I feel does not achieve a good split, I should just comment on that article's talk page. I was sort of jumping to the conclusion that it was a lost cause to address a specific article, that the whole math ship was going down, but perhaps not.

Here is a funny example though: Bayesian network. That article actually has plenty of explanations later on, but they make a concerted and heroic attempt to scare off the reader before they get to the prose.

Since I can't find the examples I was thinking of, here is a more obscure one: Volume of an n-ball. The lede is only 43-words but there are 50+ lines of equations. I read on the math style guide that you should realize people generally will skip over equations and write accordingly. But reading just the words here there is zero sense of flow or explanation of anything. It feels like a laundry list of facts. Perhaps that is what mathematicians expect in wikipedia articles? I can imagine volunteers cheerily typesetting all these equations for hours, then grumbling over spending 20-30 seconds on the lede. It wouldn't be a big deal except the article is B-class. I'm guessing "number of equations" is pretty high on the assessment criteria for math articles?

I do wonder if equations should be banned from the lede: Linear independence, Cross correlation, the style guide says "It is even more important here than in the rest of the article that the text be accessible".

Now of course the really advanced stuff is incomprehensible but that is it's own problem: Hopf fibration, Special unitary group. I highly wonder if it's possible to write anything interesting and accessible about really high level math, I have never seen it done.

I don't buy that "math cannot be explained", you have to truly work and understand it. I can read about Math without understanding it. I think that is a problem with a lot of the advanced math articles, they don't have enough about the thing. The history of its discovery and use, the importance, what concepts does it relate to. These are things any reader should be able to take away.

But I don't see the broad sweeping problem I thought. I see articles mostly attempting to be accessible, succeeding or failing to various degrees, but not a conspiracy by any means. Perhaps there are ways to steer the overall a little better, like requiring non-trivial and accessible ledes for C class and above. I think that would be a good gesture towards the average reader. 14:20, 26 February 2014 (UTC)

I don't think Volume of an n-ball is really that bad. It's not a great article, but it conveys the necessary information. In article like that, there are naturally going to be quite a few formulas, and this one is not even all that heavy. I don't think that all articles must be pitched at "any reader". We should pitch articles at likely readers. An article on the volume of an n-ball should not be targeted at readers who don't know what an n-ball is to begin with. I generally think that equations should not dominate the lead, although it would be a mistake to rule generally on that matter. For instance, obviously articles that are about an equation should be permitted to have that equation in the lead. I do think that generally equations in the lead, and to a lesser extent the text, should be minimized wherever that is reasonable. As to the history of the subject, it can be surprisingly difficult to find good accounts on the history of mathematics. Often one has to go so far as to track down and consult original articles, obscure papers in the history of mathematics, and so forth. Mathematics is unfortunately not a subject where it is common to refer to the original papers of Cauchy or Riemann or Poincare or whomeve, and unfortunately there is nothing Wikipedia can do about that. I can count on one hand the number of mainstream mathematical textbooks I have read that actually give a thorough and well-researched account of the history if their subjects. Sławomir Biały (talk) 15:25, 26 February 2014 (UTC)

I agree Volume of an n-ball is kind of an oddball case. I don't see how it's a B-class article, but it's not worth belaboring that example. I was really just using it to point out what I think are some less-good features which occur often in Math articles: inaccessible ledes and over-reliance on equations. However as I said above I was actually really impressed to see these problems are much less common than I thought, really I think there are tons of articles, I'd say definitely the majority, that do a good job on these points. However I think these are common pitfalls that should be actively warded off. It's like over-summarizing in book articles, it's just a common mis-step that is endemic to the topic.

I disagree that "likely audience" should be the goal.The FAQ above says the target is "the interested layman" except then it immediately punts and says "this is not always possible". That is way too vague. When is it not possible? How do we determine if it's not possible or the article is just not written well? Importantly: if it's not possible do we then give up completely and accessibility becomes a non-goal? Or is it still useful to strive for a somewhat accessible lede even if the article itself is super advanced?

WP:TECHNICAL says articles should be "understandable to the widest possible audience" which mostly means "understandable to a general audience". It talks about all they cases and ways most articles should be accessible to everyone. For the exceptions "like advanced mathematics" it still says "effort should still be made to make the article as understandable as possible, with particular emphasis on the lead section." It says "it is particularly important" for the lede "to be understandable to a broad readership. Readers need to be able to tell what an article is about, and whether they are reading the correct article, even if they don't already know the topic in detail". All of WP:EXPLAINLEAD is super relevant. I particularly note the request to include "the place the topic holds in its field of study" and "what (if anything) the topic is good for". I feel like that is blatantly and widely ignored.

I sympathize with the difficultly of doing any of these things for math articles, especially advanced ones. It's a really really hard problem. I just feel like the wikipedia math community has somewhat punted by saying "we are special, we just can't do it, it's impossible". I think that's a mistake, I think the goal should be to do much better, and that this can be done without removing the technical content for expert readers.

One way to improve things is just to tell people "try harder to make things accessible" but of course that will accomplish nothing. I think it would take systematic change and strong leadership to declare that accessibility is a huge goal for all articles, and to work towards that goal. It might take many years or a decade to really effect that kind of change. But I think future-wikipedia would be a much better thing if it were done well.

I'm not a math editor and not likely carry this flame. So really I don't expect much to change from my comments. But I just wanted to give my two cents since to me the problem is crystal clear. I suspect I represent a decent chunk of people who use math articles, but I'm sure math-intensive people are a bigger faction, and that is why the problem is not seen as a problem. Silas Ropac (talk) 19:53, 26 February 2014 (UTC)

I think you'll find us in agreement on the broad points. Quibbling over "general reader" versus "likely reader" isn't terribly constructive. The bigger picture is that there are many mathematics articles that need to be improved (both in terms of accessibility and otherwise). I don't mean to diminish the achievement of editors who have struggled to prove the many articles that are very good. Even the articles on special functions that I love to gripe about seem to have improved substantially in the last few years. I still think we have major weaknesses in core mathematical areas like linear algebra and differential equations. Progress in those areas hopefully comes in fits and starts. "Carry the flame" is an apt analogy. Sławomir Biały (talk) 22:15, 26 February 2014 (UTC)

I am broadly in agreement with both of you, but I have something specific to add. I wrote most of Volume of an n-ball, starting about a year and a half ago (here) and I have some insight into why it is the way it is.

I got interested in the subject because I decided that this formula was a basic computation that I should really understand; I wasn't satisfied anymore with nodding my head at every step of someone else's derivation. In a very strong sense, I wrote the article for myself. And it shows; I don't know anything about the history of the computation of these volumes, and I don't know who needs volumes of n-balls in their work (I don't), and since the article had neither of these before, it has neither of them now. I don't know much about volumes of n-balls. I just felt like learning about them. I did demand of myself, however, that I knew how and why the formulas worked, and in the process I converted the article from a pile of equations to something that, perhaps despite appearances, has exposition.

My feeling was that the primary reason why someone might read the article was because they would either want to know how the formula was derived or they would want to look up the formula. I realized that it would be easy for me to make the article useful reference, so I put quite a lot of formulas at the beginning. I added all the derivations I could find (I think the one using Gaussian integrals is really the "right" one in a sense). And I added a little other content, like the asymptotic formula in high dimensions. I don't think it's a stellar article, but I achieved my goals for it, and I'm pretty happy with how it turned out. But it's not, and never was, intended for a general audience. Ozob (talk) 03:29, 27 February 2014 (UTC)

I too write for people like me who want to know something about certain rather specialised topics in mathematics, the ones I happen to be interested in. It seems reasonable to assume that those readers already have some mathematical background. If other editors feel that articles need more explanation to make them easier to access by readers with less background than I'm assuming, then they are perfectly free to add that material. I'm not very interested in being told by other people that I should be doing what they themselves are free to do. Deltahedron (talk) 07:31, 27 February 2014 (UTC)

Well, I don't always write for myself, and I do believe that the "interested layperson" is the right audience to aim for. When I work on an article like Derivative or Chain rule, I try to aim for a less sophisticated reader; but I don't think I always succeed, and I certainly haven't written much, if any, brilliant prose. I don't know if I could ever produce an article of the quality of Homotopy groups of spheres, which I think is really outstanding. Good exposition is a very hard problem which I don't know how to solve. Ozob (talk) 15:15, 27 February 2014 (UTC)

Ozob and Deltahedron make excellent points. The fact that everyone is a volunteer with their own intentions and goals for adding content is a huge factor in all of wikipedia. As is the fact that articles get built over time. I imagine it's well documented that editors who participate at different stages of an article's development have different personalities and motives. Perhaps my criticism of Math articles is as simple as: wikipedia is not done yet. I'm having deja vu that I've come to that realization more than once, that incompleteness looks like bias. Maybe articles which are inaccessible and equation-heavy today will be fleshed out over time. Certainly the best Math articles on the most common subjects seem really good today, so maybe it's just a question of time and resources.

So long as people are additively contributing all is well. However if there are edit wars or turf battles where people trying to make articles more accessible are beaten down by those trying to keep them "pure" and expert-centered, then that is bad. I haven't edited Math articles or read many talk pages, so I can't say whether this is a problem or not. Like I said before my main take-away from this thread is if I wanted to help I should address a specific article not the whole project, which I think is a wikipedia-wide rule of thumb.

One Math-specific issue I didn't raise yet. Does WP:NOR apply to equations? I see sources cited in Math articles, but I rarely see citations on specific equations. Like in Volume of an n-ball do those 50+ equations appear verbatim in the one cited reference? Or, as seems more plausible, do Math editors take the liberty to derive or produce original content? Is there some kind of official exception to WP:NOR for Math, or is it sort of just understood that one wouldn't get very far writing about Math if one didn't do some Math in the process?

I don't really don't have a pre-conceived opinion on that one. My guess is the cat is so far out of the bag and the tide of new equations spewing forth from editors minds so torrential it would be impossible to ever enforce a strict citation policy.

However going back to my "wikipedia isn't done" comment it does lead to point. In most subjects common topics have copious references but as one narrows scope, the number of sources dwindles and the amount of content in those sources dwindles until there is simply nothing to write about. But if Math editors are allowed to more or less generate content then the natural taper goes away.

This is speculation, but it suggests the lifecycle of a Math article is just different from other types of articles and can be mis-interpreted. Rather then getting built a tiny bit a time, as cited facts are bolted on, Math articles can be quickly inflated with content, but then they have to be whittled down and framed with explanations. Again I'm making this all up, does this ever happen? Silas Ropac (talk) 15:04, 27 February 2014 (UTC)

Re WP:NOR: there is a provision WP:CALC for simple calculations and derivations, which was left deliberately vague to allow some leeway for mathematics editors to supply simple proofs. It has been extensively debated (see Wikipedia_talk:No_original_research#Counting_--_possible_addition_to_WP:CALC, Wikipedia_talk:No_original_research/Archive_58#Routine_calculations and possibly elsewhere (?)). I sort of recall it was a subject of a big hassle few years ago, about an editor who was supplying a ton of original proofs, but I don't recall the details (was it User:Mathsci perhaps?). Maybe it's worth pursuing for further refinement. No such user (talk) 15:59, 27 February 2014 (UTC)

Gosh they are talking about counting and arithmetic. My gut is people are doing major derivations and elaborations and enumerations and manipulations of formulas. But I don't know at all for real, I just get that impression looking at the articles, it looks like some of the people kind of say "well what else can I say about this" and just kind of come up with stuff which is mathematically true, but isn't sourced. But this could be "don't ask don't tell" in that 99% of editors are not going to be able to call anyone out on these transgressions. Or maybe there are no transgressions I'm one of the 99% here I really can't say. Silas Ropac (talk) 05:24, 28 February 2014 (UTC)

Why would it be necessary for all of the equations to appear verbatim in one single source? That's not even a reasonable standard for nonmathematical articles. There is of course some leeway in how things are presented, but this is the same leeway that is afforded to articles in any other subject. Regarding citations in mathematics articles, there has generally been resistance to over-use of inline citations (so you will seldom see references attached to every single equation) in favor if the recommendations of WP:SCICITE. While many mathematics article would certainly benefit from more citations or clearer attribution, it doesn't necessarily mean that original research is being committed. This is especially true of content that can be found in essentially any textbook in the relevant subject area, which actually covers quite a lot of our mathematics content. It's not unusual for a single textbook to serve as a general reference for an entire article. (The opposite situation, where a single textbook is referred to assiduously at every line if the article really looks quite amateurish and silly.) Sławomir Biały (talk) 16:29, 27 February 2014 (UTC)

Why would it be necessary for all of the equations to appear verbatim in one single source? It's not necessary in general, but in this case there were 50 equations and one source, therefore my own rudimentary math skills lead me to believe all the equations must be verbatim from that source. I mean that's the general idea, that facts are from a source and not the editor's fertile imagination? Now I can't really read any of this stuff, but my guess just from glancing at the squiggly lines, and the quantity of squiggly lines, is that there is rampant "don't ask don't tell" policy in play with Math articles. Forbidding Math editors to come up with their own equations would go over about as well as forbidding humming at a song-writers convention.

And the WP:NOR question was just out of curiosity anyway, my main concern was accessibility. I think I've more or less bottomed out on the issue by admitting there isn't a big anti-accessibility cabal which is going around obfuscating all the articles so beginners can't understand them. Instead I feel that math is hard, or at least advanced math is hard, and without a lot of effort no math article is going to be super friendly. And so a lot of the big and popular articles are in fact quite friendly, but a lot of the advanced and less common articles are not. That that's just the state of things in 2014, and maybe it will get better over time.

I pulled over thinking there was a big injustice being done and all I saw was a bunch of mathematicians working on a construction site, with one yelling "move on, nothing to see here". Silas Ropac (talk) 05:18, 28 February 2014 (UTC)

I wholeheartedly agree with this sentiment, especially that "without a lot of effort no math article is going to be super friendly". Speaking from personal experience, it is really hard (for me at least) to write articles that are both suitable for an encyclopedia and accessible to a wide audience. I don't even claim to be all that successful at it: there are some articles that I have worked on that I am quite happy with, and others less so. The latter have to be just good enough, unless and until someone makes a better attempt. It's comforting to know that Wikipedia is a work in progress. Sławomir Biały (talk) 18:30, 1 March 2014 (UTC)

In a way, you're right, there's no natural taper for mathematics. No matter what problem you're considering there is always more to say; Henri Poincare once said, "There are no solved problems in mathematics, only problems that are more or less solved." But there is a natural taper for mathematics articles. Not everything that you can say about a subject is interesting, and not everything is notable enough to be the subject of an article. Because we are supposed to be able to cite everything to a secondary source, the scope of Wikipedia is vastly more limited than that of mathematics itself.

Regarding Volume of an n-ball, no, at some point I looked at the one cited source and it didn't have all of those equations or even most of them. The article is sorely lacking references. However, it ought to be possible to find references for all the facts in the article (equations or otherwise; remember that equations are just a kind of fact). Ozob (talk) 03:21, 28 February 2014 (UTC)

Right I agree that WP:N saves us from a library of babel of Math articles. I was relieved when I realized that. So instead I think what you have is just the quirk that for Math articles one can fairly easily inject completely true but unsourced information. That's pretty hard to do in non-Math articles, unless you just happen to have the first-person knowledge. But I don't see that as a showstopper by any means. I can imagine debating WP:NOR and fighting against each and every non-sourced equation, but that doesn't interest me. I feel as long as more mature articles are more accessible and rely less on equations, I'm not sure there is anything to argue about, the bottom line seems to be just that having more mature articles is better for everyone, which is a milquetoast platform. Silas Ropac (talk) 05:38, 28 February 2014 (UTC)

WP:V is also important. Everyone makes mistakes, and I've certainly written things that I was convinced were true but in fact were false. Once you've seen yourself make enough mistakes (on Wikipedia or otherwise) the necessity of verifiability becomes clear.

Also, many (but not all) of the equations in Volume of an n-ball fall under WP:CALC. The very first one does not, and I think the next two probably do not either. But the three after that are manipulations that could be done by a high school student; I think they are covered by WP:CALC. While everything in the section "Recursions" can be derived in an elementary way from the previous section (and so I think WP:CALC might apply), I'm sure that citations for the first two formulas exist, and the article would benefit from them. I believe the two following formulas fall under WP:CALC; certainly the second equality in each does. The entire table in the "Low dimensions" section is covered by WP:CALC. The formulas in the "High dimensions" and "Relation with surface area" section need citations (but the last four in "Relation with surface area" go together; any source with one will have all four). Then we are in the proofs section. The proofs themselves need citations, but those citations will cover all the formulas that appear. The "Balls in L^p norms" section needs a citation for its first equation (though WP:CALC might cover it in light of the equation cited below), but then most of the rest counts as routine calculation. The last two displayed equations are both covered by the article's one reference. Altogether, I think that if the article were to have inline citations, it would need about fifteen more citations than it does presently to cover all the equations. Many of these would be citations to the same source or sources.

I've just added one citation to the article. Ozob (talk) 15:19, 28 February 2014 (UTC)

If an able editor makes a derivation in a math article to make it clearer to the "intended audience" it is usually not original research in any reasonable sense. It might be original, but there is typically nothing that warrants the research label, even if it is a derivation that is not to be found anywhere in the references. Straightforward application of everyday mathematics to obtain (even new) formulas just isn't research.

My 2c: Sourced equations (and derivations) are preferable to unsourced ones, but unsourced equations (and derivations) are better than no equations (and derivations). Errors (unavoidable whether the material is sourced or not) are quite likely to be caught. Now, Wikipedia has a different definition of original research, see WP:NOR. The term "research" is tied to that something isn't in print (or it is simply unknown where it is to be found) in "reliable sources". If editors just use their good judgement (they usually do that), I think they strike a fine balance. YohanN7 (talk) 17:56, 1 March 2014 (UTC)

Little orphan Annie

(No pun intended. Except that actually, I couldn't resist.)

Anne's theorem is currently an orphan: no other articles link to it. Michael Hardy (talk) 17:17, 2 March 2014 (UTC)

Insertion of Original research in several articles

Maimonid has recently edited several articles for inserting in them some texts supported by unpublished Bensimhoun's articles. I have reverted one of these edits. However some of these edits may be partially constructive, and some other eyes would be welcome. These edits include edits in

• Galois theory (reverted by myself)
• Fundamental theorem of Galois theory
• Algebraic integer
• Integral element
• Conjugate element (field theory)
• Minimal polynomial (field theory)

D.Lazard (talk) 09:36, 2 March 2014 (UTC)‎

At least one consists of adding as a reference a link to a PDF file uploaded onto Commons. This is obviously not a reliable source. Deltahedron (talk) 09:54, 2 March 2014 (UTC)

These results are so elementary that they do not need "reliable sources". They can be recognized as exact in few seconds by any person sufficiently experienced in algebra. The links to the documents with the proofs are a "bonus" here. If you think that these links are irrelevant, you could at least keep the corresponding assertions in the Wikipedia pages without linking to their proofs. Michael Bensimhoun (talk) 21:58, 2 March 2014 (UTC)

An interesting view, and one I am not entirely unsympathetic with, but Wikipedia has a policy on verifiability from independent reliable sources for a number of reasons. Firstly, so that readers, and other editors, can have some reasonable degree of confidence that the results are correct. Secondly, so that there is some degree of confidence that the results are worth mentioning. Thirdly, to prevent debates among editors, that would generate more heat than light, over points one and two. Deltahedron (talk) 22:09, 2 March 2014 (UTC)

If I'm not wrong, the problem is in the fact that I mentioned an unreliable source. What about not mentioning nothing at all, and to insert the assertion? Please, consider this paradox : on one hand, no conventional (reliable) journal would accept to publish elementary results. But on the other hand, Wikipedia do not accept publishing things that are not "explicitly" mentioned elsewhere in peer reviewed journals or books; so, there are mathematical truths and interesting observations that will be ignored for ever. Is it what you call "expansion of the knowledge"? In my opinion, a more intelligent point of view would be to "give a chance" to these mathematical truths, and to require a vote in the case where it is thought the result is suspect. Surely, for such elementary assertions, the exactness or inexactness would emerge very quickly. Michael Bensimhoun (talk) 22:42, 2 March 2014 (UTC)

It's not thought entirely polite to mention it, but here's the real issue. We're forced to hold a fairly tight line on "original research" (this is a Wikipedia term of art; it doesn't imply that anything is particularly original or research-like), because otherwise we would be overwhelmed with submissions from cranks and crackpots. We're not supposed to give much (theoretically, we're not allowed to give any) weight to an editor's credentials, so if it weren't for the OR policy, it would be very hard to prove that crankish submissions ought to be removed.

Unfortunately, it does sometimes create an obstacle non-crank editors adding useful material. But once you've been around a while, you'll probably agree that that's a necessary tradeoff. --Trovatore (talk) 23:11, 2 March 2014 (UTC)

As you might have noticed, proof outlines and supporting arguments with "unreliable references" will be challenged. But nothing prevents you from being bold. Proof outlines and supporting arguments without references may be challenged, but will not be challenged with certainty. YohanN7 (talk) 23:31, 2 March 2014 (UTC)

Let me clarify. Other editors may know of a "reliable" reference, or they may accept the argument as it stands or endow it with a "citation needed tag" for future improvement. Best is to drop a note in the articles talk page when adding unsourced material. Finding acceptable references on your own for every claim is notoriously difficult (and potentially expensive). Use your judgement. YohanN7 (talk) 23:41, 2 March 2014 (UTC)

I agree, this requires a common sense approach rather than enforcing rules for rules' sake and remembering the policies exist as a tool to serve a goal and are not really (primary) goals in their own right (and we have WP:IAR for that reason). So if you come across some obviously true material (as in easily recognizable to be true for anybody with some domain knowledge), simply don't challenge it. Of course if it gets challenged nevertheless sources will need to be added or in exceptional cases proof reading/verification by people with domain knowledge (in particular regulars of this portal) might suffice. Note that the latter only applies to things being obviously true for people with domain knowledge and may be considered an application of WP:IAR. The latter however cannot serve as an excuse for editors making unsourced edits all over the place or to cite their own unpublished results.---Kmhkmh (talk) 09:03, 3 March 2014 (UTC)

I agree with Kmhkmh. This is for this reason that I have not reverted myself all Maimonid's edits: some of them did contain not only reference to his original research, but also some text which may be useful. I had not the time for checking if this text needed or not to be challenged. D.Lazard (talk) 09:29, 3 March 2014 (UTC)

AfC submission - 04/03

Wikipedia talk:Articles for creation/AMS Centennial Fellows. FoCuSandLeArN (talk) 14:17, 4 March 2014 (UTC)

Merger of Pick matrix

Should Pick matrix get merged into Nevanlinna–Pick interpolation? Michael Hardy (talk) 18:22, 6 March 2014 (UTC)

Doing a Gscholar search for "Pick matrix" shows that, of the hits on the first two pages, most of the uses of the matrix are in the context of Nevanlinna–Pick interpolation. A merge seems reasonable to me. --Mark viking (talk) 19:14, 6 March 2014 (UTC)

Rotations, their group, and related Lie groups

Conflict in Rotation group

Short history:

1. JohnBlackburne (talk · contribs · deleted contribs · logs · filter log · block user · block log) undid my edit; ensuing discussion led to a stalemate.
2. JohnBlackburne initiated a requested move where sophisticatedly hid the question of WP:PRIMARYTOPIC of the term “rotation group” in a nominal topic, what to do with a dab page.
3. Two persons threw their “Support per nom” votes without any supplementary arguments about the particular primary topic problem.
4. JohnBlackburne used these two votes to press for redirecting Rotation group (edit | talk | history | links | watch | logs) to orthogonal group, a confusing solution as a good mathematician should realize.

I hope local frequenters will demonstrate a more thoughtful approach than the WP:RM people and so. Incnis Mrsi (talk) 11:12, 15 February 2014 (UTC)

You are disputing the outcome of the move: Talk:Rotation group (disambiguation)#Requested move. But the outcome is clear. I proposed a move, with reasons and referring to previous discussions which prompted the move, so there had already been plenty of argument. It's understandable in such cases when editors don't feel they need to restate the arguments. Of the responses two supported my reasoning, so there is consensus for the move as described in the request.

You only disagree what the primary topic for rotation group should be. In addition to the reasons given in the RM I can give two more if it helps. First the orthogonal group is known as the rotation group. See the first line of that article – I added that with a source after looking for a suitable target, before proposing the RM. The other reason is rotation group used to refer to an orthogonal group, Rotation group SO(3). That was moved from rotation group two years ago. So for much of its existence "rotation group" referred to an orthogonal group, just a particular one not a general one. — Preceding unsigned comment added by JohnBlackburne (talk • contribs) 12:45, 15 February 2014‎

This conflict is based on a big mathematical error. Please, correct it ASAP: It is said at several places (at least at the first lines of orthogonal group and of rotation group (disambiguation)) that rotations and orthogonal transformations are same thing. This would imply that the symmetry with respect to a line in the Euclidean plane would be a rotation! The correct wording is that the orthogonal group is the group of the isometries of a Euclidean vector space (that is a real vector space equipped with a positive definite quadratic form, such as the dot product). In dimension 2 and 3, the rotation group is SO(2) and SO(3) (in higher dimension, I do not remember if the rotation group is SO(n) or if the rotations have a more restrictive definition). D.Lazard (talk) 13:25, 15 February 2014 (UTC)

I don't see the errors you refer to. It says in orthogonal group and in the disambiguation page that orthogonal group and rotation group (usually) refer to the same thing, which is the reason for the move, supported by the arguments in the RM and above. rotation group, not rotations, which are something different and much less formally defined. But if you think it could be improved go ahead, or describe what changes should be made here.--JohnBlackburne^words_deeds 14:15, 15 February 2014 (UTC)

It is wrong that "orthogonal group and rotation group (usually) refer to the same thing". "Rotation group" is the same thing as "special orthogonal group". D.Lazard (talk) 14:30, 15 February 2014 (UTC)

I see what you mean. The problem is that's the same article: special orthogonal group redirects to orthogonal group. I would say it's less clear cut which is the rotation group – the special orthogonal group is the group of all proper rotations, so the group of all (proper and improper) rotations is the orthogonal group. But the outcome of the move would be the same: rotation group would redirect to orthogonal group (if it's made to redirect to special orthogonal group a bot will quickly change it back as that's a double redirect). Any subsequent problems should be addressed by editing the article and disambiguation page.--JohnBlackburne^words_deeds 15:00, 15 February 2014 (UTC)

Will creation of the special orthogonal group article be an acceptable compromise? I am willing to settle on it, but John’s abomination in the present form can’t be tolerated. Incnis Mrsi (talk) 14:55, 15 February 2014 (UTC)

They were merged a long time ago. I don't think so old an article is a useful guide but it's hard to see how a separate article will help. There's almost no content in orthogonal group unique to the special orthogonal group, so you end up either with a stub with almost nothing in that's a disservice to readers, or largely duplicating orthogonal group with all the problems that involves of extra maintenance, articles getting out of sync.--JohnBlackburne^words_deeds 15:10, 15 February 2014 (UTC)

Pin →	O	⊂ U
Spin →	SO	⊂ SU

You are not right: there are some correspondences (see the table) that could be spelled separately for G- and S-cases; note that [each other two columns have // my grammar mistake: should read “each of two other columns has” Incnis Mrsi (talk) 17:34, 15 February 2014 (UTC)] a pair of separate articles. Also, the orthogonal group virtually excludes the indefinite orthogonal group case, whereas the Special orthogonal group (edit | talk | history | links | watch | logs) should not do it and may consider all determinant-1 matrices/operators that are orthogonal with respect to certain quadratic form, including SO(3;1), as well as relevant subgroups such as SO(3;1)⁺. Incnis Mrsi (talk) 15:32, 15 February 2014 (UTC)

It should be obvious that SO(3) is the rotation group and that nobody thinks of O(77) as a group of rotations and that SO(n) is rotations in n dimensions. It is also obvious that SO(3) (whatever you call it) deserves an article of its own. YohanN7 (talk) 15:44, 15 February 2014 (UTC)

And it has one: Rotation group SO(3). As can be seen from that, and Rotations in 4-dimensional Euclidean space the interesting properties of SO(n) are most apparent from considering them for particular values of n. Circle group completes the set of low-index special orthogonal groups. The names could be more consistent but there's not an obvious right thing to call them.--JohnBlackburne^words_deeds 16:02, 15 February 2014 (UTC)

No big problem then, good. (I didn't read the above too carefully apparently.) I wouldn't oppose a split of Orthogonal group into O(n) and SO(n) (or whatever we choose to call them). I believe that there is enough "substance" in the two to make up two separate articles, at least in the long term. YohanN7 (talk) 16:58, 15 February 2014 (UTC)

---

@D.Lazard: stop to push your “SO(2), SO(3) and SO(4)” crap into the lead section of the orthogonal group: it reintroduced a confusion between real numbers and an arbitrary field that I once worked hard to eradicate. Re-join the discussion and express your opinion: would a new article be a solution, or ? Incnis Mrsi (talk) 16:52, 15 February 2014 (UTC)

@Incnis Mrsi: Undoubtfully, the primary meaning of orthogonal group refers to the reals. I have carefully rewrote the lead of orthogonal group for making this clear, by describing the generalizations (to other fields of other quadratic forms) after the main meaning. My so called "crap" has been introduced in a paragraph clearly (maybe not enough clearly) devoted to the real case, and these links, as well as the fact that these case have been widely studied, are important form an encyclopedic point of view. In my opinion, this is the confusion between the primary topic and its generalizations which is confusing. D.Lazard (talk) 17:18, 15 February 2014 (UTC)

@Incnis: This kind of pettifogging is unconstructive. Wikipedia articles often proceed from the specific, but common, to the general but uncommon. Even most professional mathematicians would consider the orthogonal group to be over the real numbers. When referring to groups over an arbitrary field, it is always either explicitly said, or is in the context of linear algebraic groups or similar. Sławomir Biały (talk) 17:21, 15 February 2014 (UTC)

I consider this as an implicit support for splitting. One hardly can substantiate such heavy emphasis on S groups in the lead section about a non-S group. Incnis Mrsi (talk) 17:34, 15 February 2014 (UTC)

If a split should occur, it should be by restricting Orthogonal group to the real case (related to Euclidean distance), and creating Orthogonal group over a field. Similarly, we have already Indefinite orthogonal group. D.Lazard (talk) 18:52, 15 February 2014 (UTC)

Which problem will be solved? The lead became bloated with the S-related stuff after your late edits, and it will remain bloated regardless of whether “non-standard” fields will be expunged or not. Incnis Mrsi (talk) 20:26, 15 February 2014 (UTC)

I don't have strong opinions about a split one way or another (implicitly or otherwise). I was merely responding to your apparent point that the case of the reals needs to be de-emphasized. Sławomir Biały (talk) 19:45, 15 February 2014 (UTC)

I meant primarily that Daniel’s three links through redirects are self-contradicting: the article says there are O groups over any field, but sends the reader to articles about real groups via unspecific O(n) titles. I didn’t say the real case has to be specially de-emphasized, but the lead section become bloated and a bit confusing after late D.Lazard’s edits. Incnis Mrsi (talk) 20:26, 15 February 2014 (UTC)

We must not forget that the orthogonal group (over the reals) is not only a concept of pure group theory, but also an important geometrical concept, widely used in mathematics, physics and mechanics. On the other hand, as far as I know, the generalization over other fields is considered only in pure group theory. As the article must be accessible to a much wider audience than only group theorists, this must help to give a due weight to the primary topic (over the reals) and its generalizations. D.Lazard (talk) 23:06, 15 February 2014 (UTC)

The orthogonal group for a general quadratic form over a general field is certainly not "considered only in pure group theory", although it is indeed important there. It is important in, for example, number theory and field theory (see for example the books of O'Meara, or Lam, or Cassels). Deltahedron (talk) 07:24, 16 February 2014 (UTC)

Classical groups

Much of the content in the current lead in Orthogonal group should really be in Classical group. That article could well serve as an umbrella for articles on particular classical groups. See also Talk:Classical group#Not B-class. YohanN7 (talk) 22:02, 15 February 2014 (UTC)

It may be worth noting that the Encyclopaedia of Mathematics article Orthogonal group begins "An orthogonal group is a group of all linear transformations of an n-dimensional vector space V over a field k which preserve a fixed non-singular quadratic form Q on V" while Reflection group begins "A discrete group of transformations generated by reflections in hyperplanes". I personally prefer the more general definition of orthogonal group. Deltahedron (talk) 22:09, 15 February 2014 (UTC)

Will it help to solve the current problem, or it is an independent suggestion? Incnis Mrsi (talk) 20:26, 15 February 2014 (UTC)

It will not help solve the problem with the disambiguation page (if that is what is the current problem), but it can be taken into consideration if Orthogonal group is split. The stuff about bilinear forms need not be repeated in each classical group article, it is common to all of them except for SL(n, C) (and the exceptional ones if you count them as classical). By the way, I don't think we need to have such a broad interpretation of what a rotation is, SO(3) as the rotation group and SO(n) as a generalization would work. "Improper rotations", "rotations in spacetime" and the like serve no purpose really. YohanN7 (talk) 22:02, 15 February 2014 (UTC)

And by extension of my above reasoning, it would be strange to have "rotation group" redirect to "orthogonal group" or for it to have "orthogonal group" as the main dish. YohanN7 (talk) 22:14, 15 February 2014 (UTC)

The exceptional ones are not classical by definition. There is also a broad concept rotation (mathematics) article. @YohanN7: please, explain yet a time: which articles should, in your opinion, serve the O(n, F) and SO(n, F) topics? Incnis Mrsi (talk) 12:58, 16 February 2014 (UTC)

@Incnis Mrsi: I haven't explained even one time which articles should serve the general field topics. I'm thinking about the definition and classification of the classical groups in terms of bilinear (sesquilinear) forms. This should in my opinion go into Classical group in a more thorough way than today. I frankly have too little knowledge about groups over general fields to even have an opinion about where they should be treated. But I do feel that the fields R, C and H should be treated within the same article for each "abstract" group we treat separately. Probably then, the O(n, F), etc, should each have a section in the general O(n), etc, articles. Some people (the real connoisseurs) count the exceptional groups among the classical groups (but I don't). Yes, I have references supporting that statement, but this is not important. YohanN7 (talk) 16:00, 16 February 2014 (UTC)

Quaternions are a division ring, not a field. There is the GL_n (although with two incompatible natural representations), but there isn’t neither SL_n nor O(n). You must reserve special clauses to define the determinant that isn’t matrix multiplication-invariant at last, you must care about the order of factors everywhere (such as in bilinear forms), and you can’t define orthogonality as a symmetric relation. One would be more successful in generalizing these groups to commutative rings than over structures where the multiplication does not commute. Incnis Mrsi (talk) 16:29, 16 February 2014 (UTC)

Division ring, non-commutative field, whatever. See Wulf Rossmanns Lie Groups - An introduction through linear groups for a thorough treatment of GL(n, H), SL(n, H), (S)U(p, q), Sp(p, q) and (S)O*(2n). These are groups over the quaternions, very successfully generalized to them. YohanN7 (talk) 17:42, 16 February 2014 (UTC)

See a follow-up at talk: Classical group #Matrix groups over non-commutative rings. Incnis Mrsi (talk) 12:20, 18 February 2014 (UTC)

But you are right about symmetric bilinear forms. They don't yield anything interesting (I think they are automatically degenerate, not sure, can check this out later) in the quaternionic case. I was thinking more generally in terms of all classical groups. YohanN7 (talk) 17:52, 16 February 2014 (UTC)

Rotation operator (vector space)

This title is problematical, not the article separated from its title. In absence of alternative suggestions I’ll move the article to three-dimensional rotation operator, fix inbound links from other articles, redirect the former title to rotation operator, a dab page, and edit this dab with addition of the rotation (mathematics) choice. Incnis Mrsi (talk) 16:19, 5 March 2014 (UTC)

Let's not forget Rotation formalisms in three dimensions. Personally I think there should be one article on rotations in three dimensions, rather than several that treat basically the same topic with slightly different emphasis. Sławomir Biały (talk) 19:02, 5 March 2014 (UTC)

I never forget about “rotation formalisms…”. But may I move the article in question, in the absence of an instant solution, before doing anything else? Otherwise one can forget to fix the erroneous Rotation operator (vector space) (edit | talk | history | links | watch | logs) title and such invalid links will pollute Wikipedia further. Incnis Mrsi (talk) 12:34, 9 March 2014 (UTC)

I think a merge would be a better solution than having two essentially identical articles, whatever their titles happen to be. Sławomir Biały (talk) 13:10, 9 March 2014 (UTC)

Mirror symmetry

Hello,

I just wanted to let everyone know that the article on mirror symmetry (string theory) is currently a featured article candidate. It would be great if some of the mathematicians on Wikipedia could review the article. If you're interested, you can leave a comment on this page. Instructions for reviewers can be found here. Thanks. Polytope24 (talk) 17:28, 9 March 2014 (UTC)

Request for help

Hey, WikiProject Math,
I just reverted some edits at Curve that didn't look constructive. But this article doesn't get a lot of views and I'd like it if someone who had more familiarity with geometry than me (i.e. my sophomore year in high school) could confirm that these deletions of text were not an improvement. Thanks! Liz ^{Read! Talk!} 22:58, 9 March 2014 (UTC)

An edit like [1] seems like an improvement to me. -- Taku (talk) 12:41, 10 March 2014 (UTC)

Cramér's conjecture

Marek Wolf (talk · contribs) and a set of anonymous editors (or one editor acting from multiple IP addresses) have been trying to add a 2014 paper published by Marek Wolf, and a conjecture named by Wolf after himself, to the Cramér's conjecture article. Deltahedron (talk · contribs) and I have reverted for now but more eyes would be helpful. There is also a discussion of this issue on the article talk page for which additional contributions would be welcome. —David Eppstein (talk) 23:14, 1 March 2014 (UTC)

I note that similar material appears in Prime gap. There is also a Marek Wolf-generated figure in each article. --Mark viking (talk) 23:32, 1 March 2014 (UTC)

And in Cousin prime. YohanN7 (talk) 01:38, 2 March 2014 (UTC)

There is also a mention of Wolf in Riesz_function, which someone who knows something about the subject should assess for relevance. --JBL (talk) 02:04, 2 March 2014 (UTC)

I am far from an expert in the subject but (without an error term) the equality asserted in this mention looks nonsensical. —David Eppstein (talk) 02:22, 2 March 2014 (UTC)

Indeed, and on reading the paper by Wolf it appears that the RHS is indeed the leading term in a series for the Riesz function, not the function itself. Deltahedron (talk) 07:41, 2 March 2014 (UTC)

I've reported the IP that has been the source of most of the recent edits for edit-warring. --JBL (talk) 01:49, 2 March 2014 (UTC)

In spite of all this, I do hope that it will be possible to explain the local customs to User:Marek Wolf: the best possible outcome would be to have him join as a constructive editor contributing content in his field of expertise. Deltahedron (talk) 09:57, 2 March 2014 (UTC)

New ip user around: 46.205.82.65 YohanN7 (talk) 14:36, 2 March 2014 (UTC)

User:Marek Wolf has now been blocked for a week. I do not think that was the best way of dealing with this situation. Deltahedron (talk) 17:44, 2 March 2014 (UTC)

An ip user is at it again. This time at Prime gap. YohanN7 (talk) 21:58, 4 March 2014 (UTC)

The changes at prime gap [2] are incorrect, as can be easily verified. I have not read the original Wolf paper (the link in the article is dead) to see if the formula given there is also incorrect. (Clearly, g(p) ~ log^2 p is too strong: g(p) < 7*10^7 infinitely often as Zhang proved.) The changes at Cramér's conjecture refer to the maximal gap G(p) and so look fine mathematically (it's just an issue of Wikipedia notability). CRGreathouse (t | c) 22:42, 10 March 2014 (UTC)

A draft at AfC needs help

Please take a look at WT:Articles for creation/Shreni Integration and help get it into shape - if it is a notable topic of course. Roger (Dodger67) (talk) 19:09, 10 March 2014 (UTC)

Google provides no evidence of this term ever being used for anything. --JBL (talk) 19:59, 10 March 2014 (UTC)

Looking at the content, it's just some sort of iterated integration by parts. I don't think there's any chance this is notable. --JBL (talk) 20:03, 10 March 2014 (UTC)

It seems like WP:OR to me. There is at least no indication that this is a notable series under the name "shreni series" or "shreni integration". Sławomir Biały (talk) 22:43, 10 March 2014 (UTC)

Invitation to Participate in a User Study - Final Reminder

Would you be interested in participating in a user study of a new tool to support editor involvement in WikiProjects? We are a team at the University of Washington studying methods for finding collaborators within WikiProjects, and we are looking for volunteers to evaluate a new visual exploration tool for Wikipedia. Given your interest in this Wikiproject, we would welcome your participation in our study. To participate, you will be given access to our new visualization tool and will interact with us via Google Hangout so that we can solicit your thoughts about the tool. To use Google Hangout, you will need a laptop/desktop, a web camera, and a speaker for video communication during the study. We will provide you with an Amazon gift card in appreciation of your time and participation. For more information about this study, please visit our wiki page (http://meta.wikimedia.org/wiki/Research:Finding_a_Collaborator). If you would like to participate in our user study, please send me a message at Wkmaster (talk) 15:32, 11 March 2014 (UTC).

I'd guess video communication would also require a microphone. I don't have a webcam; otherwise I might be curious about what this is. Michael Hardy (talk) 16:51, 11 March 2014 (UTC)

Distributive property of division

Since ${\frac {a+b}{c}}={\frac {a}{c}}+{\frac {b}{c}}$,

why isn't the property mentioned in the Division article? Hill Crest's WikiLaser! (BOOM!) 04:35, 13 March 2014 (UTC)

Never ask why something has not been done in Wikipedia! Just do it yourself! JRSpriggs (talk) 07:32, 13 March 2014 (UTC)

It probably wasn't done because it isn't explicitly the distributive property of division. It follows directly from the distributive property of multiplication. However, it can reasonably be mentioned in division. Robert McClenon (talk) 01:03, 16 March 2014 (UTC)

Indexes in sums

There is a discussion at talk:volume fraction about using or not using different indexes in a fraction where the numerator V_i is included in a sum that appears in the denominator. Some mathematical feedback would be useful.--188.26.22.131 (talk) 10:23, 17 March 2014 (UTC)

intersection of sin x and cos x in a graph

where do the intersection value of x and y cross each other ? I can see the value of x in radian is at$\pi /4$ but y is around ${\frac {1}{14}}$70.53.125.83 (talk) 21:17, 16 March 2014 (UTC) Never mind it's intersection is at ${\frac {1}{\sqrt {2}}}$or $\sin {45}and\cos {45}$

Consider $\sin ^{2}(x)=1-\cos ^{2}(x)$. This will reduce to finding special values of sine or cosine. Some better places to ask these questions are on the talk page, Wikipedia:Reference desk/Mathematics, or a dedicated Q&A like math.stackexchange. ᛭ LokiClock (talk) 01:46, 17 March 2014 (UTC)

Please: Write $\sin ^{2}(x)=1-\cos ^{2}(x)$, not $sin^{2}(x)=1-cos^{2}(x)$. TeX and stripped-down TeX such as that used here were designed well. Michael Hardy (talk) 17:44, 18 March 2014 (UTC)

I do in general. ᛭ LokiClock (talk) 14:08, 19 March 2014 (UTC)

If you really want to annoy Michael Hardy, ${\mbox{do this}}$.  :-D Sławomir Biały (talk) 22:18, 19 March 2014 (UTC)

@70.53.125.83 : The proper place for questions like this is Wikipedia:Reference_desk/Mathematics. This page is for discussion of the creation, maintenance, and improvement of Wikipedia's coverage of mathematics. Michael Hardy (talk) 17:46, 18 March 2014 (UTC)

Elliptic curve primality

I had merged Elliptic curve primality testing and Elliptic curve primality proving and after merging I moved the Elliptic curve primality proving to a new page called Elliptic curve primality. Had I done anything wrong.Please leave a message regarding this to my talk page.--Skr15081997 (talk) 14:14, 21 March 2014 (UTC)

No new articles on the current activity page

For several days there have been no new articles at Wikipedia:WikiProject_Mathematics/Current_activity. I've sent emails to Oleg Alexandrove and to Jitse's bot. Am I the only person who notices this? Michael Hardy (talk) 19:35, 21 March 2014 (UTC)

You're certainly not the only person who notices, and thanks for taking some action about it. —David Eppstein (talk) 19:59, 21 March 2014 (UTC)

Maybe wikipedia is finally finished? --Salix alba (talk): 21:59, 21 March 2014 (UTC)

Not even close. -- Taku (talk) 23:51, 21 March 2014 (UTC)

I can think of one mathematics article that's not there yet and should be. It will take some work . . . . . Michael Hardy (talk) 15:08, 22 March 2014 (UTC)

Rather more than one. Deltahedron (talk) 17:05, 22 March 2014 (UTC)

Oleg has told me the problem is now fixed.

We're hanging by a thread: Jitse Niesen runs the bot that updates the current activities page; Oleg Alexandrov runs the bot that maintains the list of mathematics articles, which Jitse's bot relies on for the information one new articles; and I am the only person who points out to them when one of the bots is not working. For more than five years I've been the only one who does that (unless there are some isolated excecptions). If the three of us were assassinated (or maybe any one of the three) the Universe would collapse. Michael Hardy (talk) 15:06, 22 March 2014 (UTC)

Semi-invariants of quivers

There is a new article called Semi-invariants of quivers. Should it be changed to Semi-invariant of a quiver or the like? Michael Hardy (talk) 18:22, 26 March 2014 (UTC)

I do not believe anymore that Wikimedia can ever discourage certain kind of new users from dumping their blurry waste to Commons. Incnis Mrsi (talk) 18:41, 26 March 2014 (UTC)

Issues of blurry waste aside, I agree that the article should be moved to Semi-invariant of a quiver in keeping with WP:SINGULAR. --Mark viking (talk) 19:21, 26 March 2014 (UTC)

AfC submission - 25/03

User:The tree stump/Fingerprint Database for Theorems. FoCuSandLeArN (talk) 11:45, 25 March 2014 (UTC)

This submission is based entirely on an AMS Notices article by Billey and Tenner (the article's first reference). The Billey and Tenner article is a primary source for the concept of a fingerprint database for theorems, because they define such databases and propose that the mathematics community make a systematic effort to construct them. The article linked above presents no evidence that this idea is notable. While Billey and Tenner present several examples of such databases (e.g., the OEIS), in that capacity they are serving as secondary sources for the notability of those examples. They can't be a secondary source for or establish notability of a concept that they introduce. Ozob (talk) 14:19, 25 March 2014 (UTC)

I like the idea of such a database very much, but at this point it seems to me premature to have an article on it given the lack of secondary sources. Sławomir Biały (talk) 14:02, 27 March 2014 (UTC)

Links to Erdős–Nicolas number

Nothing currently links to Erdős–Nicolas number except the List of things named after Paul Erdős. Michael Hardy (talk) 17:43, 27 March 2014 (UTC)

Is this draft about a notable topic?

Wikipedia talk:Articles for creation/Benacerraf's identification problem - I have asked WikiProject Philosophy the same question. Roger (Dodger67) (talk) 13:27, 28 March 2014 (UTC)

It's about philosophical questions that most mathematicians pay little attention to, so I'm not sure anyone here will be able to help. I can say that at least the mathematical part is not nonsense (unlike some mathematical philosophy). Ozob (talk) 14:07, 28 March 2014 (UTC)

AfC submission - 26/03

Is there anything salvageable from Wikipedia talk:Articles for creation/Sieve of Nicholls? FoCuSandLeArN (talk) 02:29, 27 March 2014 (UTC)

No. This is clearly pure WP:OR, someone attempting to publish their own work on Wikipedia. Bill Cherowitzo (talk) 03:41, 27 March 2014 (UTC)

I agree — this is exactly what I was about to write. —David Eppstein (talk) 03:47, 27 March 2014 (UTC)

The OR is miles deep. Anything worth salvaging would be too hard to find to make it worthwhile. Sławomir Biały (talk) 14:09, 27 March 2014 (UTC)

It appears to me that Wikipedia talk:Articles for creation/Sieve of Nicholls is _not_ an attempt to flout the policy against original research, but simply a result of unawareness of the existence of that policy. Michael Hardy (talk) 23:01, 29 March 2014 (UTC)

• Cheers for that. What about Wikipedia talk:Articles for creation/Mean log deviation? FoCuSandLeArN (talk) 14:44, 27 March 2014 (UTC)

Who is a mathematician?

There appears to be a disagreement on Vi Hart over whether she should be categorized as a mathematician. Additional opinions welcome. —David Eppstein (talk) 05:48, 31 March 2014 (UTC)

This has now expanded to a debate on what an Amature mathematician is and to the creation of Category:Amateur mathematicians. Which is now listed at Wikipedia:Categories for discussion/Log/2014 March 31#Category:Amateur mathematicians. --Salix alba (talk): 09:56, 31 March 2014 (UTC)

I am working on many things in this WikiProject. Feedback and suggestions please?

Recently, I made my first big edit to Triangular number, in which I derive the entire formula to find the triangular roots of a number, and explain the form of the second triangular root.

I am asking for feedback and advice for editing these types of articles. Hill Crest's WikiLaser! (BOOM!) 22:59, 22 March 2014 (UTC)

Notice that Pairing function makes use of triangle numbers and triangular roots. JRSpriggs (talk) 00:40, 23 March 2014 (UTC)

Another big edit readied up at Heptagonal number. Hill Crest's WikiLaser! (BOOM!) 03:44, 23 March 2014 (UTC)

One hint: Indent equations using a colon. YohanN7 (talk) 09:59, 23 March 2014 (UTC)

Okay, one suggestion. If you are not a programmer, then forget about the asterisk (*) symbol until you learned about one of few things in higher mathematics that actually use it in the notation. Read the multiplication article to learn how to denote the multiplication. You can also consult a MoS. Incnis Mrsi (talk) 11:26, 23 March 2014 (UTC)

Correcting the symbols right now. Hill Crest's WikiLaser! (BOOM!) 14:09, 23 March 2014 (UTC)

Perhaps more importantly — I assume you derived the formula entirely by yourself? If so, nice work, but unless you can point to an independent reliable source that can be used to verify your material, it is original research and we just cannot use that. Deltahedron (talk) 12:36, 23 March 2014 (UTC)

The derivation becomes trivial when one understands the quadratic formula. And also, where did all those tests on the polygonal number pages come from? Hill Crest's WikiLaser! (BOOM!) 14:08, 23 March 2014 (UTC)

Very detailed derivations are not generally included in articles. Because the formulae are trivial consequences of the quadratic formula, we should say just that. Sławomir Biały (talk) 14:13, 23 March 2014 (UTC)

If you don't like how I edited, go ahead and change them. Hill Crest's WikiLaser! (BOOM!) 14:16, 23 March 2014 (UTC)

You asked for suggestions and feedback. You received some very good advice, so there is no need to feel or sound bitter. YohanN7 (talk) 15:17, 23 March 2014 (UTC)

Ok, striked out that comment.Hill Crest's WikiLaser! (BOOM!) 20:52, 31 March 2014 (UTC)

Not to forget, a gnome that appears in the article with a tiny correction amidst a series of major improvements by another editor can be an annoying factor because of edit conflicts. Of course, I could wipe out the asterisk heresy myself as I did hundreds of times. But after Hillcrest98 asked for suggestions, it seems that a direct editing of articles by other users is not warranted (sorry, my English is sometimes awkward). Incnis Mrsi (talk) 15:50, 23 March 2014 (UTC)

In sequences like Padovan sequence and Perrin number, should we put the index numbers of the sequence in parentheses or subscripts? Hill Crest's WikiLaser! (BOOM!) 20:52, 31 March 2014 (UTC)