I added a request to put the recently featured article about groups on the main page. This system is a bit complicated, and the article being showcased probably depends on whether groups are "similar" to Emmy Noether, which was displayed on the main page some weeks ago. If you are interested in having a mathematics article showcased (and not the (n+1)st video game), please join in the discussion over there. Jakob.scholbach ( talk) 17:34, 26 October 2008 (UTC)
So what happened to this discussion? It is evident from the queue that the article will not appear on October 29th, that date that was proposed, but what decision was made ought to be available somewhere. Maybe with some archive of the discussion. Do things like that exist, or does the whole thing vanish from all memory? Michael Hardy ( talk) 01:22, 29 October 2008 (UTC)
Somehow, it did get selected quite soon (so, much ado about nothing from my part...), namely tomorrow, November 5. Perhaps people around can have an watching eye on it during that day. Jakob.scholbach ( talk) 07:52, 4 November 2008 (UTC)
Suppose ab=cd, suppose you let a=0 and c=0. Can you then write b/c = d/a ? Can you further say this is valid for all values of a and c ?
User:Bakken is claiming you can say these things because they are true in the limit.
See here: Talk:Lorentz transformation#There is nothing wrong in dividing by zero. Delaszk ( talk) 17:55, 3 November 2008 (UTC)
You are assuming that ab = cd. If a = 0 and c = 0 then b/c and d/a are not well defined. It is clearly true that if ab = cd then b/c = d/a provided that b/c and d/a are well defined, i.e. ac ≠ 0. Whenever we divide by zero we get a contradiction. Consider the famous example. Assume that x = y then after multiplying through by x we get x2 = xy. Subtracting y2 from both sides gives x2 - y2 = xy - y2 . Which, after factorisation gives (x + y)(x - y) = y(x - y). Dividing through by x - y gives x + y = y. Assuming that x = y gives 2x = x, and finally dividing through by x gives 2 = 1. Clearly 2 ≠ 1, and so we have a contradiction. The contradiction came from dividing through by x - y and then assuming that x = y, i.e. dividing through by zero. I don't think that projective space is involved here. If it were to be, and the person posing the question knew that it was, then the question wouldn't be posed in the first place. Be careful of limits. Limits and equalities are not the same thing. Δεκλαν Δαφισ (talk) 23:07, 3 November 2008 (UTC)
Bakken, you say that "You cannot avoid a genuine singularity in a physical system by mathematical transformations." What about the simplest case of the the transformation T(f)(x) := exp(f(x)). Let the function f be given by f(x) := -1/x2. It follows that the transformation of f is smooth and well defined for all x; T(f)(x) has no singularity at all, but f had an honest singularity that can not be removed by any change of coordinates. Δεκλαν Δαφισ (talk) 10:59, 5 November 2008 (UTC)
A web site about tangrams; sorry if it's off-topic, but the article makes a lot of references to math software. VG ☎ 02:28, 6 November 2008 (UTC)
I recently came across the article Vector resolute, which is also known as vector projection. I had not heard of this terminology before. Googling the term "vector resolute" turns up about 709 results, and the term "vector projection" turns up about 13,000. I would like to change the article from vector resolute to vector projection, as I see it as the more common term, and move the links so that it points the other way. I cannot decide if this would be inappropriate behavior, so I thought I would ask first. Thenub314 ( talk) 07:39, 6 November 2008 (UTC)
OK, I've moved it, and I've fixed the link from template:linear algebra. If you go to vector projection and click on "what links here", you may find many links to the redirect, but most of those will be shown as direct links to vector projection after my edit to the template propogates (if I'm right in guessing that most links to that article result from the template). In 24 hours or so, if you click on "what links here" again, you'll see the actual links to the new redirect page, and then those can be fixed. Michael Hardy ( talk) 19:12, 6 November 2008 (UTC)
This template should probably be updated to include the full range of quality and importance categories. For example
List of International Mathematical Olympiads is a featured list but the FL link on
Talk:List of International Mathematical Olympiads is currently was red.
MSGJ
14:09, 6 November 2008 (UTC)
It now appears that group (mathematics) will be "Today's Featured Article" on the main page very soon (tomorrow?).
But there's a glitch: The image of Rubik's Cube featured prominently right at the top of the article is proposed for deletion. The argument is that it's a copyrighted work and therefore any photograph of it is a "derivative work". And people who are not aware of the relevant facts or of copyright law are participating in the discussion, urging deletion. The discussion is [ here]. Michael Hardy ( talk) 16:45, 4 November 2008 (UTC)
I don't think that's a good resolution. That image has been there for a long time, and nobody challenged it until it got schedule to appear on the main page in a day or two. Why is that? Michael Hardy ( talk) 16:54, 4 November 2008 (UTC)
Unfortunately the vandals are winning, even if they fail to get the image deleted. They will probably prevent its schedule appearance at the top of the main page.
We need to find a good image quickly. The snowflake image is distinctly inferior, and I don't mean just as a work of visual art. It is inferior as a means of illustrating the mathematical idea that this is about. Michael Hardy ( talk) 17:17, 4 November 2008 (UTC)
OK, you don't like my style. But what about my actual point: We need to find a good image fast. Michael Hardy ( talk) 18:15, 4 November 2008 (UTC)
There's something to be said for Alexander's Star, but I think the Rubik's Cube picture much more clearly convey's the idea of transforming by turning one side, and that's what corresponds to the group's binary operation. Michael Hardy ( talk) 21:42, 4 November 2008 (UTC)
Just wait until the preacher says "Speak now or forever hold your peace" to bring up something that could have been dealt with privately earlier, so you can make a public show of humiliating people to punish them for good work. That's what's happened here. This will be remembered for a long time. The story of this incident will be the whole content of the comprehensive biography of the persons responsible. A hundred years after the deaths of that person, or those persons (I don't really know who or how many), this is what they will be remembered for. This is all that they will be remembered for. Michael Hardy ( talk) 01:11, 5 November 2008 (UTC)
I thought the article actually discussed the 3x3x3 cube's group. Since it doesn't, there are a number of images that are not of the 3x3x3 cube. It looks like the 4x4x4 cube is not produced by the same lame company [1], so I don't see an immediate problem, as there's no obvious copyright claim on the web to poke us with. BTW, a number of free screen savers use the 4x4x4 and 5x5x5 cube, but don't offer the 3x3x3 cube. I think I've figured out why :) VG ☎ 01:37, 5 November 2008 (UTC)
Looks good. user:r.e.b.'s recently installed picture is better than the snowflake, but these Rubik-type things actually illustrate the motions. Can we get this installed fairly quickly? Michael Hardy ( talk) 02:57, 5 November 2008 (UTC)
If anyone here has a moment or two, please comment on the Proposed Changes thread at talk:Monty Hall problem. -- Rick Block ( talk) 03:48, 8 November 2008 (UTC)
Is there any point to this article or can it be deleted, redirected or merged? I'm not a maths person so I don't know. Cheers — Realist 2 13:29, 7 November 2008 (UTC)
I've added some context and links to make the article more readily comprehensible. The user who created it also created a bunch of other severely stubby articles about gears with no initial context-setting. One of them read as follows (the whole article):
I'd have thought that was about dentistry rather than mechanical engineering (the article has improved since then). Michael Hardy ( talk) 02:32, 9 November 2008 (UTC)
Is there a way to label an equation or something à la
and have a label somewhere else ("equation (1)")? The link, much the same way as one has footnotes, should be such that if the reader clicks at the link, the equation or at least the label at the eqn. is highlighted in light blue. Jakob.scholbach ( talk) 20:40, 7 November 2008 (UTC)
Another contributor to the Exponentiation article wants to change it in a way I believe is very much against the ethos of an encyclopaedia. The latest discussion is at Talk:Exponentiation#exp(x). The other contributor Bo Jacoby ( talk) is not about to go away soon, he has been trying to change various things in the article for the last three years. Is there a way of mediating or coaching so the exchange is a bit more fruitful, or do you judge that would be fruitless and the rumbling is at a low enough level that it can just go on for then next few years - or have you any other ideas for a more productive use of time? Dmcq ( talk) 13:32, 8 November 2008 (UTC)
There is currently (or more rather a two years old) merge discussion on its talk page. Could an administrator please sort it out?
Topology Expert ( talk) 08:40, 8 November 2008 (UTC)
Correction: The merge discussion is 11 months old (initiated by User:Arcfrk)
Topology Expert ( talk) 08:42, 8 November 2008 (UTC)
The second of these three articles is mostly about comparametric plots. That part of it should get merged into comparametric equation. Michael Hardy ( talk) 02:59, 9 November 2008 (UTC)
I have created the article titled Regiomontanus' angle maximization problem. Probably it could profit from other points of view. Everybody's seen this problem in a calculus course, but I think it is far less well known that there's a simple solution via elementary geometry. In addition to those two, I've included a solution by simple algebra. Michael Hardy ( talk) 03:02, 9 November 2008 (UTC)
Topology Expert ( talk) 11:31, 9 November 2008 (UTC)
Thank you. I'll cite at least one textbook. Michael Hardy ( talk) 02:27, 10 November 2008 (UTC)
A new editor, user:Xzungg, is repeatedly making some POV edits to Skolem's paradox. I have integrated the positive parts of his edits into the article already, and commented on the talk page. I could use the assistance of a couple other editors to help determine a consensus about the article content. — Carl ( CBM · talk) 14:20, 9 November 2008 (UTC)
I have nominated the biography Kevin Houston for deletion at Wikipedia:Articles for deletion/Kevin Houston. Please feel free to comment there, but please use tact, since the discussion is public and there's a decent chance Houston may read it someday. — Carl ( CBM · talk) 14:29, 10 November 2008 (UTC)
Hi,
This is Bill Wedemeyer, a biochemistry professor at Michigan State University. I apologize that this message is not directly related to mathematics, but please bear with me for a moment. I've come to ask for your help, especially the help of my fellow professors.
I recently became aware of The Core Contest, which was run last year for a few weeks (Nov 25 – Dec 9). Briefly, it was an article improvement drive focusing on basic articles that belong in the "core" of an encyclopedia, with awards of $100 promised for the five most improved articles. For example, one of the articles was Hypatia of Alexandria, which belongs to this WikiProject.
My impressions are that (1) the contest was remarkably successful in improving articles and (2) many younger students threw themslves into it, body and soul, partly for the fun of it but also in the hopes of winning the prizes. Unfortunately, circumstances seem to have conspired to prevent those prizes from being awarded.
I'd like to amend this and reward the prizes, as they were promised. I'm willing to sponsor the awards myself, but I hope you agree that it'd be more fun and more wiki-spirited if we all joined in. I'm especially interested in recruiting professors, who I think will want to be kindly to poor but hardworking students, especially in this season of many holidays. We probably all remember what it was like to be a poor student.
I've contacted Prof. Martin Walker (one of the judges of the contest) about the matter, and he's very supportive. Please contact me by e-mail if you're interested in donating to the cause. We would plan on announcing the winners in two weeks, on November 25th, the anniversary of the contest.
Thank you, Proteins ( talk) 18:31, 10 November 2008 (UTC)
I'm glad that the first responses are so positive, and that people aren't mad at me for posting something off-topic. It's true that writing good articles about topics so vast in scope is hard, although it's also true that many might benefit from such articles. I don't mean to say that these articles are more important, or more crucial to the success of Wikipedia than, say, group (mathematics). As a professor, I think my own articles would have to be specialized, too; by report, professors' knowledge has increased and their scope narrowed so much that they know practically everything about practically nothing. ;) My interest in the Core Contest is purely personal. It pains me to see students working hard and then disappointed, and I suspect that others will want to join me in setting things right. Proteins ( talk) 19:43, 10 November 2008 (UTC)
PS. My special thanks go out to Prof. Tsirelson, the first person to write me and volunteer his help!
Proposed, anyway. It's not categorized yet, but would be somewhere in Mathematics. — Arthur Rubin (talk) 15:16, 7 November 2008 (UTC)
As for this article, sure, let's delete that. However, to take us slightly off topic, let me point out that the theorem that the kth-root of a natural number n that is not a kth-power is irrational is of significance historically. For example, Theodorus claimed to have proven the square root of n (except 4, 9, and 16) up to 17 is irrational, and explanations of how he could have done this form a non-negligible body of scholarship. Part of the speculation rests on the assumption that he did not know the fundamental theorem of arithmetic. Indeed, as pointed out in Hardy and Wright's text on number theory, the fundamental theorem of arithmetic is not required for the proof that kth-root of a natural number n that is not a kth-power is irrational. Elementary methods analogous to that of proving square root of two is irrational can be used. -- C S ( talk) 21:06, 7 November 2008 (UTC)
...are things that sit there for LONG periods of time with no attention from anybody. For SEVERAL YEARS now, this has sat in the article titled Gottfried Leibniz:
y = x. That's what it said. The graph of that equation is a straight line; the area under it is the area of a triangle. Obviously Leibniz was not the first to find the area of a triangle; obviously you don't need integral calculus to do that. I've changed it to read as follows:
Note that I changed "the" to "a". Several years ago, this got quoted on the main page and consequently ridiculed here on this page, and then it got fixed on the main page. But not in the Leibniz article. People may argue about whether Archimedes' various quadratures that anticipate Leibniz's work but did not use the fundamental theorem of calculus mean that the words "for the first time" are right. But the part where it says y = x is so idiotic that one should wonder: is there some way of making the process of bringing Wikipedia's content before the eyes of knowledgeable people can be made systematic enough that glaring things like this will be seen? Michael Hardy ( talk) 22:40, 11 November 2008 (UTC)
If the article was correct, it really needs to get phrased differently from the way it was. Michael Hardy ( talk) 04:36, 12 November 2008 (UTC)
I understand what you mean. It is sometimes frustrating to have an article where absolutely no-one bothers to read or add to the discussion page. If I post a comment one day, I probably won't get a reply for at least a year. But I have to deal with it. That is why most of the time I follow the following:
a) If it is a 'popular' article to edit, I comment at the discussion page and someone will probably see my comment within a week and respond.
b) If it is unlikely that someone will ever respond to my comment (if I make one), I will probably just make the edit I want to anyway (saves a lot of time and trouble).
Maybe there should be some sort of way of monitoring a page (other that watching) that involves a group of editors who discuss changes to the page in question quite often. On each page we could have a list, and editors could add themselves to that list provided that they monitor that page frequently (at least once per month). If many editors participate in this 'project', they could be evenly distributed over most of the math articles. I don't know whether this is a good idea but I think it is at least a slight improvement compared to the features we have now.
Topology Expert ( talk) 13:55, 12 November 2008 (UTC)
Occurrence-in-subtuple problem has been "prod"ed. Does anyone know anything about this? Michael Hardy ( talk) 13:51, 15 November 2008 (UTC)
The vector space article currently says: "The ultrafilter lemma, which is weaker than the axiom of choice, implies that all bases of a given vector space have the same "size", i.e. cardinality. citation needed" Can somebody provide a reference for this, please? I didn't find one. Thanks, Jakob.scholbach ( talk) 14:25, 15 November 2008 (UTC)
In the "solution by algebra" section in Regiomontanus' angle maximization problem, I've put in a show/hide button that's not working. Can anyone figure out why? Michael Hardy ( talk) 20:16, 10 November 2008 (UTC)
Why I want to do it would be clear from what I wrote there, I would think. I know others have done this in various other math articles. Has this problem occurred elsewhere? Michael Hardy ( talk) 22:06, 10 November 2008 (UTC)
It's not about hiding "boring derivations"; it's about hiding things that interrupt the main line of argument that is the point of the section or paragraph or passage, but that might nonetheless be of encyclopedic interest.
Also we have a policy requiring articles to be accessible to a broad audience. This furthers that policy. Michael Hardy ( talk) 03:36, 11 November 2008 (UTC)
I actually like the idea of the show/hide button. It is something an online encyclopedia can do but which a paper one cannot do, so it should be exploited! There are many cases when a casual reader would not want all the details of a proof/derivation, but someone really trying to understand the topic would want to read. MSGJ 17:45, 11 November 2008 (UTC)
I also changed this template to the one User:Ben Tillman put instead of the previous algebra stub template. Again this is more representative of number theory (and that is why I changed it (I don't really think having the numbers 0,1 and 2 is useful although 1 and 0 may have some (slight) significance)). Hopefully there are no objections but if you have any, please post them and I can discuss.
Topology Expert ( talk) 05:56, 16 November 2008 (UTC)
Does anyone else have an opinion on this?
The former, using \emptyset, looks like something that shows up because you're using an old-fashioned typewriter with a correspondingly limited character set, so you type the digit 0 and then backspace and type a slash over it. So I prefer the latter, using \varnothing. Michael Hardy ( talk) 19:17, 16 November 2008 (UTC)
Is there really no choice of font? When I make an \emptyset in pdflatex, on my own LaTeX installation, it comes out nicer than the one here. See this screenshot: . Aspect ratio seems to be about 3:2 (not counting the slash) whereas the WP one is more like 2:1, which seems too much. -- Trovatore ( talk) 07:01, 17 November 2008 (UTC)
Is there a way of forcing a character to be bigger or smaller in tex on WP? I tried out \large and some options in \mbox but it complains about anything I do. I notice for \varnothing people were getting screen images to make it larger so I guess it's not possible, but my reading of tex says I should be able to do something like \mbox{\large 0} but I can't get anything along those lines to work. Dmcq ( talk) 15:26, 17 November 2008 (UTC)
Occurrence-in-subtuple problem, an article about a combinatorial problem said to have applications in genetics, has been nominated for deletion. It is obvious that the reason for some of the imperfections in writing is that it was written by someone who is not a native speaker of English. That of course is a reason to clean it up, not to delete it. The substantial objection seems to be an allegation of original research, concerning which I have no settled opinion. Michael Hardy ( talk) 05:11, 18 November 2008 (UTC)
Can someone provide precise statements of the theorems of Kolmogorov and Arnold that are mentioned in a hand-waving way in Hilbert's thirteenth problem? Some sources on the web speak of "superposition", which I usually think of as meaning addition, but some other speak of "composition", which I usually think of as something quite different from addition. The Wikipedia article ought to give a precise statement of the problem if possible. Michael Hardy ( talk) 06:11, 18 November 2008 (UTC)
I have seen the template:
(removed now that discussion is over becase otherwise this page would be classified as an 'algebra stub' once archived)
on several pages and I was wondering whether this template could be changed (this maybe a bit difficult and I don't know the rules so I am assuming that this can be done). The reason being is that it does not really reflect what 'algebra (modern)' is; rather it reflects high school algebra. Maybe in a way it reflects field theory (in a vague way!) but it does not reflect group theory very well. I think that there could be a more 'representive' symbol. Any opinions?
Topology Expert ( talk) 11:20, 9 November 2008 (UTC)
But I am not sure that fifth-graders are supposed to understand this. Moreover, a fifth grader would probably interpret the symbol as 'high-school algebra' (which is rather reasonable for someone who has never heard of the subject). Perhaps we could still make it 'easy to understand' and 'representative of modern algebra'?
I agree with what User:Delaszk said because the most appropriate symbol would probably be one that reflects the fundamental idea behind group theory (and that is of course the binary operation). Could we implement this or do we need more people to agree?
Topology Expert ( talk) 00:50, 10 November 2008 (UTC)
Topology Expert ( talk) 07:57, 10 November 2008 (UTC)
Could someone please tell me how (and I could do it)?
Topology Expert ( talk) 07:39, 15 November 2008 (UTC)
I'm just wondering why these stub templates need images at all. Would not
suffice. What encyclopedic purpose does the image really serve, they just take up screen space and distract the eye.-- Salix ( talk): 08:22, 16 November 2008 (UTC)
As I have mentioned already, a simple image such as sqrt(x) or a^n + b^n = c^n is representing the wrong field of maths (one representing arithmetic and the other is representing number theory). I can get a different image and try it out, perhaps, if other people also disagree entirely with this image. But I think (and I hope others do to) that we need a proper image and all the previous ones were not at all satisfactory.
Topology Expert ( talk) 09:55, 16 November 2008 (UTC)
Take the current {{ Cattheory-stub}} template which is basically (not mathematically) the same as this one.
Topology Expert ( talk) 09:58, 16 November 2008 (UTC)
What about this one:
that illustrates the compatibility of two different structures on a field (that make it into a bialgebra). If not this one, I would say that the following image could also work (quite a simple commutative diagram that illustrates the associativity of monoids (assoicativity is something that a fourth grader could understand)):
Any opinions?
Topology Expert ( talk) 10:42, 16 November 2008 (UTC)
Unfortunately, no one seems to understand my point. My point is that we want something that represents modern algebra. Not some junk like a square root symbol that makes an ordinary person believe that mathematics goes as far as a square root (and believe me, there are people who think this). Furthermore, this is not the sole purpose of the image. We also want the image to represent a fundamental idea behind group theory. I do like the image given by Jakob.scholbach, but a cube does not represent the fundamental idea behind group theory. A concept such as the binary operation or a commutative diagram that illustrates the compatibility of two different structures on a field would really represent this field of mathematics better (the binary operation would be the best). If you want something easier to understand (now lets face it, there are mathematicians who don't know much group theory (or category theory)), then choose something like this:
This commutative diagram represents the associativity of the binary operation in a monoid (which would be understood by any real mathematician). We definitely can't (and don't want to) aim for an average (non-mathematician) to understand the image; we want the image to be understood by someone who has had some decent formal training in mathematics (or who is learning group theory). And anyone who knows what a function is would probably understand a (simple rectangular) commutative diagram.
So if you don't like the current image, the one I just suggested may be better. Any opinions? If there is still disagreement, I can try for another image but I would like to have the opinions of several mathematicians.
Topology Expert ( talk) 12:21, 16 November 2008 (UTC)
Thanks for the opinion. What I don't understand is why we can't make the image 100px which is not too large and is still (reasonably) visible to the naked eye:
Why wouldn't this work?
With regards to algebra and category theory, I am quite confident when I say that category theory was invented based on algebra and then expanded to other fields of mathematics. For instance, 'isomorphism' is common to both fields and I can list quite a few others which are active terms in algebra as well as in category theory. If you analyse the commutative diagram carefully, it basically illustrates (the fact) that in a monoid, the binary operation is associative.
Topology Expert ( talk) 12:57, 16 November 2008 (UTC)
As I mentioned earlier, one cannot decipher what the current category theory stub template is about either ({{ Cattheory-stub}}) but that has been there for a long time. At least 100px is visible and not too large. Why in Wikipedia, does everything have to follow strict rules?
Topology Expert ( talk) 12:59, 16 November 2008 (UTC)
I agree with what you say about the importance of the image. But at least this image is better than sqrt(x) and I bet that someone who knows calculus could easily learn what a commutative diagram is. Furthermore, we don't expect everyone to understand it; as long as an algebraist can understand it, its fine. The image should just be a representation of the field and not part of an article, so people are not expected to understand the image.
Topology Expert ( talk) 03:45, 17 November 2008 (UTC)
Topology Expert ( talk) 06:05, 17 November 2008 (UTC)
I can't believe there's serious debate over whether abstract algebra should be represented by a 75px image of a commutative diagram, no matter how algebraic the fact it encodes. The idea, in addition to being absurd from a visual design perspective, borders on the snobbish: why does the stub template have to represent some fact of "real" math, one phrased in a language that, admittedly, is not understood or appreciated by most students and a good number of practitioners? Anyone who sees this stub, however amateur at algebra, should understand that it's talking about something they might know; ask yourselves if, as undergraduates, you would have had that reaction to the associativity square. I think this point is amply supported by Topology Expert's own words: if a calculus student could "easily learn", or someone familiar with functions could "probably understand" a commutative diagram, then it is too complicated; we should not be arguing over whether the picture is potentially comprehensible, but whether it is thematically suitable. We may not care whether non-mathematicians get it, but we had better not be so elite as to dismiss college students (or, God forbid, analysts :) ).
Furthermore, category theory is totally unnecessary for understanding what algebra is about, and writing associativity as a commutative diagram is obfuscatory unless there's a more general game afoot. Granted, saying "algebra is square roots" is rather a dumbification, but not every level of abstraction below the One True Abstraction gives a misleading picture of the subject. Algebra, in itself, is a subject concerned with sets, elements, and operations, not objects and arrows (however much about the former they reflect), and understanding it at just that level is enough to, say, get you a Fields Medal, if you do it right. Ozob's suggestion is an excellent one: it expresses a fact basically characteristic of algebra (if you see a binary operation, and it's associative, then you are in the midst of defining an algebraic structure) in a concise way that, if you learned any algebra at all, you learned this first. Ryan Reich ( talk) 01:23, 18 November 2008 (UTC)
Topology Expert ( talk) 04:05, 18 November 2008 (UTC)
Also, category theory is the centre of mathematics and every single branch of mathematics has objects and arrows anyhow.
Non-associative algebra may still be algebra but you will have to agree that associativity (except for closure of course) is the most fundamental axiom in algebra.
Topology Expert ( talk) 04:38, 18 November 2008 (UTC)
Take this massive comutative diagram for instance:
How else would you describe what a Hopf algebra is (unless you want to tediously find a series of equations that are equivalent to this commutative diagram)? Commutative diagrams are a easy (and natural) way of storing information and are everywhere in advanced mathematics. I am probably telling you what you already know, but my point is that you shouldn't be afraid to include a commutative diagram in a supposedly 'lower level' mathematics like algebra. Furthermore, I can also bet you that everyone who knows algebra well, will also know what a commutative diagram is. Isn't that what we want?
Topology Expert ( talk) 06:44, 18 November 2008 (UTC)
Topology Expert ( talk) 02:00, 19 November 2008 (UTC)
(By the way, associativity is to groups as Hausdorff is to topological spaces. Many mathematicians don't care about non-Hausdorff spaces but that does not mean that Hausdorff spaces are unimportant).
Topology Expert ( talk) 03:28, 19 November 2008 (UTC)
Why would you think that is boring? When I first learnt about these infinite cardinalities, I was fascinated (and excited to prove by myself that ).
Topology Expert ( talk) 03:35, 19 November 2008 (UTC)
Topology Expert ( talk) 05:15, 19 November 2008 (UTC)
Great! I just thought of something much better (represents algebra well, very easy to understand, and also quite important)! What about an exact sequence? We could choose a simple sequence consisting only of three objects. For instance:
Practically everyone knows that represents the integers and practically everyone has a vague idea as to what the arrows are (a function). This would be more exciting as an image, more concise, and much better than a dinosaur commutative diagram. Any opinions on whether or not this would be preferable to a commutative diagram?
Topology Expert ( talk) 05:28, 19 November 2008 (UTC)
As I mentioned, we want to expand people's knowledge (one purpose of Wikipedia) and this stub template is excellent for this (allows people to learn about the mathematical subject of category theory).
Topology Expert ( talk) 05:46, 19 November 2008 (UTC)
Well, if I were feeling cynical, I could point out that most of the students in a course I'm teaching never heard of Euclid until I mentioned his name (I don't know how you can do that and be a high-school graduate) and they certainly don't know what the blackboard bold letter Z represents. And guess what they "know" that the arrows mean? Here's an example:
That what "almost everybody knows" the arrows mean. Michael Hardy ( talk) 05:54, 19 November 2008 (UTC)
There are two things that I have learnt in the past 10 days:
a) Wikipedia can be a big waste of time sometimes (good fun though)
b) The world is a lot dumber than I thought
(you must really get sick of teaching your students; I don't know how you do it)
Topology Expert ( talk) 06:31, 19 November 2008 (UTC)
The Rubik's cube has the following flaws:
1. It is too colourful and gives the wrong impression of mathematics (people may think that to solve a Rubik's cube, you need to be good at maths and if you can solve it, you must be the best mathematician around (believe me, people think this already; we don't want to give them encouragement)).
2 (more importantly). It only represents finite group theory and does not have a wide scope. One user mentioned that the commutative diagram only represents associative algebra; at least it represents a wider scope of algebra compared to the Rubik's cube.
Any arguments against my points? (some support would be much appreciated)
Topology Expert ( talk) 08:06, 19 November 2008 (UTC)
Because of the apparent stupidity of the outside world, I want to make a point that this template should only be aimed at real mathematicians (any mathematician knows what an exact sequence is (or at least what an arrow means (or Z (hopefully)))).
Topology Expert ( talk) 08:11, 19 November 2008 (UTC)
a) Give an image which people (who don't know maths) are clueless about so they stop talking nonsense
b) Give an image which is really important in the intersection of mathematics with algebra
Commutative diagrams are wonderful for both purposes. As I mentioned, the image that User:Ozob suggested is mathematically equivalent to the commutative diagram and furthermore, gives more meaning to mathematics.
You are probably sick and tired of me arguing so I won't argue for so long. I just wanted to emphasise that:
a) The Rubik's cube is unsatisfactory (in my opinion) for the reasons I have already mentioned
b) User:Ozob's image is mathematically equivalent to mine
(You probably don't want me arguing any longer and as you said, it doesn't matter what image we choose; the words are more important. Since no one (except for me) is going to analyse the image, we might as well keep the commutative diagram unless of course it discourages people from expanding a stub (which is unlikely)).
I just wanted to make one quick (and very important point); algebra is a subject which almost any mathematician (and student) knows at least a little bit about. Therefore (with the number of algebraists around), any algebra stubs must contain really deep concepts within the field (because very few people would have known enough to expand it and hence it is a stub). So really, anyone who can expand an algebra stub, will probably know algebra well and hence what a commutative diagram is. The more simpler concepts can be edited by college students because they won't be stubs (generally between stub and good article mostly).
Topology Expert ( talk) 12:45, 19 November 2008 (UTC)
Also (to Brwian), category theory is very important in mathematics (see category theory and perhaps homological algebra for an example). Topology Expert ( talk) 12:54, 19 November 2008 (UTC)
To Brwian: what about sheaf theory?
Topology Expert ( talk) 02:54, 20 November 2008 (UTC)
OK, so there are a few basic concepts which are stubs. If I make them 'unstubs' now, we can accept the commutative diagram? I will start with trinomial.
Topology Expert ( talk) 02:58, 20 November 2008 (UTC)
( edit conflict) Most of the users have bailed this discussion so I think the vote is pretty much, 'who cares', although some users still strongly hate the commutative diagram. My point is that the commutative diagram encourages editors to learn about category theory. Have a look at this and you will find that the template is more descriptive and people will not think that it is a smudge anymore. Furthermore, the new description encourages readers to learn about category theory: a bonus because anyone who knows calculus (well, unlike Michael Hardy's students) will be able to learn the basics of category theory.
Topology Expert ( talk) 03:50, 20 November 2008 (UTC)
Topology Expert ( talk) 04:06, 20 November 2008 (UTC)
Topology Expert ( talk) 04:49, 20 November 2008 (UTC)
I have a better idea. There was no agreement over which image to use (some people liked the rubik's cube, some preferred the associative rule, some people don't give a monkeys). However there does seem to be consensus that the image is not very important - it's the text that is important. So I have removed the image and just left the text. I agree this discussion has gone on far too long. TE it is understood that your intentions are entirely good; however you should have realised earlier that your opinions were not gaining support. MSGJ 09:53, 20 November 2008 (UTC)
Topology Expert ( talk) 11:17, 20 November 2008 (UTC)
So in TE's style, please type below: (No reasons/discussion required, thanks.)
Votes will be counted tomorrow. MSGJ 19:12, 20 November 2008 (UTC)
Topology Expert ( talk) 23:53, 20 November 2008 (UTC)
I know that I am alergic to stub templates but how about this one:
Since most people here want a 'geometric' image of group theory, this one is perfect. It is also quite clear and reperesents the circle as a group (in fact a Lie group; the circle is one of the most common, simple examples of these).
What Delaszk said explains something: algebra has a lot to do with category theory (and as I mentioned, category theory originated from algebra (hence the term 'isomorphism')). Maybe one day, category theory will be a huge part of algebra (galois theory, in my opinion, is a mix of category theory and algebra!).
Topology Expert ( talk) 01:14, 21 November 2008 (UTC)
How does this look?. I suggest looking at:
before judging (every college student who does algebra will know that the circle is a group with multiplication).
Topology Expert ( talk) 02:36, 21 November 2008 (UTC)
Huh? On Locally finite group and Affine Grassmannian, the associativity equation appears but on Trinomial, no image appears! There must be an error because of so frequent changes (or maybe it just comes up like that on my computer).
Topology Expert ( talk) 02:41, 21 November 2008 (UTC)
I have nominated the vector space article for WP:Good article nomination#Mathematics. I'd be thankful if people around could have a look, particularly those knowledgeable in analysis. Jakob.scholbach ( talk) 09:28, 18 November 2008 (UTC)
P.S. There are two other current nominations (nominated by other editors), Mayer-Vietoris sequence and Robert Hues. I'd like to encourage people to review articles. It's fun, usually pretty interesting and helps the author of the article a lot. Thanks, Jakob.scholbach ( talk) 09:36, 18 November 2008 (UTC)
Topology Expert ( talk) 07:54, 19 November 2008 (UTC)
First:
Second:
First, within "math" tags:
Second, within "math" tags:
At radius of convergence, this first form was failing to get rendered. Why? Michael Hardy ( talk) 23:30, 18 November 2008 (UTC)
The problem seems to have been fixed. I edited the article and it looks good now. Michael Hardy ( talk) 18:14, 19 November 2008 (UTC)
DYK has started keeping track of which article have received the most page views while being featured on the Main Page. See Wikipedia:DYKBEST. DYK would like to make its section of the Main Page more effective. We are in need of Wikipedians who can review the raw Wikipedia:DYKBEST data and come up with factors that make it more likely that an article will receive page views. If interested, please feel free to review the data and edit Wikipedia:DYKBEST#Features_of_an_effective_DYK_hook. Thanks. -- Suntag ☼ 08:22, 20 November 2008 (UTC)
Don't fear the heading; wait till the end of my message. A non-mathematician keeps reverting my changes to this but I found a perfect image. To make this discussion short, have a look at this. Then type either 1 (for agree with my image) or 0 (if you disagree). No explanations required. If my image is not favourable (after 5-7 people vote), I will immediately revert my inclusion of that image. Please decide on the basis of the image rather than the previous discussion and also note that my image represents the connected sum (differential geometry). Anyone can understand that the image illustrates two objects being glued together and furthermore, this is more representative than a dodecahedron.
Topology Expert ( talk) 11:49, 20 November 2008 (UTC)
If necessary, the image size can be increased by a few pixels and this should make it more clearer.
Topology Expert ( talk) 11:51, 20 November 2008 (UTC)
Ok (you don't have to say sorry by the way). First of all, I had a dispute with User:Moondyne regarding something else and he threatened to block me. Next, he started tracing my edits and reverting them (these edits were mathematics-based). I didn't mean to be rude, but I am trying to expand Wikipedia. If users threaten to block me, be rude ( User:Moondyne), don't agree with me (I think users are against me now but I can't do anything about it) and undo my edits, then it seems that it would be best if I retire. And I know that no one really would care if I retired (I have better things to do anyhow (as everyone here does)). I also don't see why User:Ben Tillman had to bring something irrelevant into this discussion.
I have to keep my promise, but the image I put up is representative of geometry (differential geometry in fact and also has very important applications in fibre bundle theory), small and clear, easy to understand, and probably the same as the previous image except for the fact that they represent different topics. What is the problem (you don't have to answer this and if no-one does I might as well revert my inclusion of that image)?
Topology Expert ( talk) 12:48, 20 November 2008 (UTC)
By the way, there was an edit conflict and I just wanted to note that the connected sum belongs to differential geometry.
Topology Expert ( talk) 12:48, 20 November 2008 (UTC)
Please note also that many of the articles in {{ geometry-stub}} are about things Euclid would recognize as geometry, which may be very different from the things a modern mathematics department's hiring committee would recognize as geometry. — David Eppstein ( talk) 15:32, 20 November 2008 (UTC)
You may as well revert then. I thought it was quite visible but that's my opinion. Anyway, Euclid was 2000 years ago, as far as I know no-one works in Euclidean geometry any longer.
But now that I look at it, maybe I will vote 0 as well.
Topology Expert ( talk) 23:44, 20 November 2008 (UTC)
Topology Expert ( talk) 02:13, 21 November 2008 (UTC)
But isn't it better compared to the image of the dodecahedron?
Topology Expert ( talk) 02:19, 21 November 2008 (UTC)
By the way, metric geometry and Euclidean geometry are different fields. What you cited was a result at their intersection. I have not read the proof, but does it use the Euclidean metric?
Topology Expert ( talk) 02:22, 21 November 2008 (UTC)
0 The dodecahedron is good because it is visible (unlike the other proposed image) and immediately conveys "geometry" to even a non-mathematician. siℓℓy rabbit ( talk) 02:28, 21 November 2008 (UTC)
I have indeed made mistakes in the past, but so have quite a few people in this discussion (I can't think of anyone who has not made mistakes; take Cauchy for instance. He thought that every separately continuous function was continuous and yet he is such a famous mathematician). I also think that many people would make the occasional mistake, at least, if they did not have access to much (if any) 'mathematics information'.
I learn mathematics by thinking (by working out results on my own and just reading the bare minimum of the definitions). Therefore, I make mistakes sometimes and of course, I may have some misconceptions. Even now, I make mistakes (now and then) but hopefully this should not be seen as vandalizing. I can also safely say that the field I know best is topology (but I know other fields reasonably well too) (believe it or not, I can prove many topology theorems on my own (including published ones such as Urysohn's lemma (no hints whatsoever)). I don't mean to boast, but I am just defending myself from people who think they are 'better' because they have higher qualifications. By 'topology expert' I do not claim to be better than everyone anyway. Even though you may not know my real name either, if you did, you would get quite a few (respected) results on the internet if you searched it up; plus I have been on television (thought this is irrelevant, at least it illustrates that I have some credentials). Since you already suspect it, I might as well admit that I am nowhere near a first year student but that does not say that I may not know graduate maths. I also hope that I am not judged because of this; if so, Wikipedia is discriminatory. Users such as User:Hans Adler and User:David Eppstein may be famous but that should not mean that they can attack annonymous users. I appreciate that some users don't consider themselves better because of their credentials ( User:Plclark, Silly rabbit and many other such editors in this discussion for instance) and even silly rabbit: he does not give his real name but I certainly do not doubt that he knows maths very well.
One more point. Apart from a textbook on topology, I don't have many mathematics resources. Therefore, to learn maths, I am inclined to learn the necessary definitions from Wikipedia (then I can think about these definitions for years!). This has led me to start editing Wikipedia. Every single person has the right to learn mathematics. I mean, I can buy textbooks if necessary, but why not take advantage of a free encyclopedia such as this one. If I thought I was so clever, I would not spend time editing Wikipedia and furthermore, I always defend Wikipedia (you'd be amazed at the number of people who think Wikipedia is rubbish). In fact editing Wikipedia also helps me to learn; I read an article on a concept (say if I was learning what a topology was) and I change any incorrect statements based on the definition. This is a really efficient way of learning and furthermore, Wikipedia has imbedded in it the opinions of many mathematicians which is very good. This also explains why I am not a fan of references; most of the things I add to Wikipedia are from my head (even theorems and results but after hearing about WP:OR, I stopped this).
Think whatever you like of me but just because I maybe younger than you (and high-school students) does not mean that I cannot have the same credentials (you can't say that it is impossible for a 13-year old to publish something let alone a first year student). In fact, I have almost done so.
Topology Expert ( talk) 13:08, 21 November 2008 (UTC)
Well, I don't really want people to think me any differently knowing that I am younger than a high-school student. I just wanted to illustrate that someone can know maths even without having a PhD. I guess sooner or later people would have found out (not being a fan of references is an indicator).
I guess we should forget about the algebra stub template discussion (and I will leave them alone) so we can get back to normal editing. I suggested a circle though... (revert if you think it is not good (no need for voting)). I am currently looking to improve locally connected space and fibre bundle (an article especially in the need on attention). Perhaps knowledgeable users can contribute?
I can go by the fact that I shouldn't meddle in number theory for instance because I don't know anything about it. That's what I meant when I argued about qualifications and knowledge.
Topology Expert ( talk) 14:14, 21 November 2008 (UTC)
Oh, and just something that might interest you ( User:Dmcq is that the second edition of Counterexamples in topology costs less than $10 so you might as well buy a copy.
Topology Expert ( talk) 00:59, 22 November 2008 (UTC)
P.S Just to note there is a at least one field medalist who contributes to Wikipedia.
Does that make it better? Is the one you know a mathematician (if you look at the Wikipedia:Wikipedians with articles page, one is listed)? As I know Oded Schramm also could have probably won a fields medal (if he was younger) but that's just for interest.
Topology Expert ( talk) 03:59, 22 November 2008 (UTC)
Topology Expert ( talk) 01:04, 23 November 2008 (UTC)
On the note of content, I do hate people tracking down my edits (most of the time not finding any mistakes but then exaggerating one mistake in a few months to at least some being problematic). But they will soon get tired of it when no mistakes come up.
Topology Expert ( talk) 01:04, 23 November 2008 (UTC)
I am not sure if this discussion is still active, but I think that the current geometry stub template picture, Template:Geometry-stub is perfectly fine and is much better than the connected sum picture. The connected sum is fundamentally a topological rather than a geometric concept so it is not really appropriate for a geometry stub template. Connected sum might be a topology template candidate, but again I think that the current picture of the Klein bottle used in Template:Topology-stub is perfectly fine and does not need to be replaced. Nsk92 ( talk) 01:19, 23 November 2008 (UTC)
My reply to User:Nsk92: The connected sum has several applications in the theory of fibre bundles. OK, perhaps the definition of the connected sum is topological. But what is the purpose of the connected sum? The connected sum is 'geometrical' because it has a lot of applications in differential geometry.
Topology Expert ( talk) 03:13, 23 November 2008 (UTC)
Distances and angles, only??? Manifolds are used mostly for geometry. I am not saying manifolds have nothing to do with topology (they are of course important in this field) but which topic are they most used in (Riemannian geometry as you mentioned is a subfield of geometry)?
Topology Expert ( talk) 07:24, 23 November 2008 (UTC)
The article, geometry is getting vandalized (more than twice every day) by idiots who have nothing better to do than vandalize. Can't we do something about it? For at least the whole time the article existed, most edits are either:
a) Vandalizm
b) Reverting vandalizm
Something has to be done. I would suggest:
a) Semi-protect the article (more important)
b) Block vandalizers for a day for any vandalizm; increase this block to a week, then a month etc.. until an indefinite block if abuse is repeated. I think that vandalizers are dealt with too lightly on Wikipedia.
But since I am not an admin, I would leave the decisions to a real one.
Topology Expert ( talk) 07:33, 23 November 2008 (UTC)
A single-purpose account User:Boolean hexadecimal, proposes replacing a large amount of text in tables with a large imagemap (so that the text is replace by an image of text). The image is not only less clear than the tables, it's awful for accessibility. Could someone else look into this? — Carl ( CBM · talk) 20:56, 18 November 2008 (UTC)
Hi,
what I like about the representation above is the following:
Concerning accessibility:
It is true, that articles should also be accessible to blind people, and for plain text uses, may it be for wapedia or whatever. I take that very serious. But in these cases a table containing wikipedia math symbols would be not useful as well. Thus a good solution for all kinds of users is to keep the imagemap template in the article, and to add a note like this: " Here you find this information in plain text."
The lines in this table should simply look like this:
The information displayed in the Hasse diagram can be shown by a simple list of conclusions like these:
I can create this subpage Logical connectives text table, if you agree that it makes sense. I think it does.
Greetings, Boolean hexadecimal ( talk) 12:19, 26 November 2008 (UTC)
As many people here are probably aware, there is apparently a bug causing LaTeX formulas to no longer appear. It seems like texvc refuses to regenerate pngs, like it doesn't know that the previously cached images are no longer available. This has happened before, but it was always fixed within hours of the problem appearing. The problem now has been ongoing for several days. Does anyone here know if the devs are aware of this problem? If so, is some effort being made to fix the problem? How long should we expect this to continue? siℓℓy rabbit ( talk) 13:55, 23 November 2008 (UTC)
I'm finding yet another instance in golden ratio just below the words "Number of the Beast". Two lines of unrendered TeX code. Purging hasn't helped. Michael Hardy ( talk) 20:08, 24 November 2008 (UTC)
I don't believe purging helps. Last time I checked, was not working either. — Carl ( CBM · talk) 00:25, 25 November 2008 (UTC)
Thank you, Brion. Michael Hardy ( talk) 03:27, 26 November 2008 (UTC)
Looking at the assessment and categorisation of mathematics articles it seems to me that many improvements can be made and this WikiProject can be brought more into line with other projects. There could be several advantages to this.
My main proposal is that we convert the project banner {{ maths rating}} to use the standard meta-banner Template:WPBannerMeta. I have done quite a bit of work on this and the result is currently at Template:WikiProject Mathematics. It does not look exactly the same as the current one - I've got some examples to show you below. Other proposals are:
Please see my sandbox for various different combinations. In order to show comments it was necessary to use mainspace, so I've pasted the proposed new banner on the following pages to demonstrate:
I will take personal responsibility to ensure that any changes work as desired and any teething problems are fixed. Your thoughts please? MSGJ 20:48, 17 November 2008 (UTC)
Well that's one thing that seems to be decided then (stick with Priority over Importance). Does anyone have any answers to my three questions? MSGJ 07:03, 19 November 2008 (UTC)
The new template does not "categorize" Bplus articles as B articles – it completely replaces the Bplus class with B class. So there would be no more Bplus articles at all. In the past there has been support for keeping the Bplus rating. What do people thing now? — Carl ( CBM · talk) 14:18, 20 November 2008 (UTC)
Keep B+. It serves a useful purpose. linas ( talk) 04:27, 4 December 2008 (UTC)
Our longstanding consensus has been that the maths rating template is for rating math articles, not for tagging every page that is somehow related to math. Since the new banner template is quite willing to allow people to tag templates, categories, etc. with it, that's a problem. We could add a check to the template so that it only works on Talk: pages and not on other pages. It's really a pain to have to go back through and fix these after they have been mistakenly tagged by a well-intentioned editor (I know from experience). — Carl ( CBM · talk) 14:20, 20 November 2008 (UTC)
Regarding proposal 5 above, it seemed to me that these categories had too much information on them and were very cluttered. You needed to scroll down a long way to actually see what articles were in those categories. My proposal is to have some brief information about assessing articles and a link to a page with the full details. The more standard method is just a simple template at the top which links to the other categories (see this [[:Category:B-Class Berbers articles|example). I know a lot of work went into the WikiProject_Mathematics/Wikipedia_1.0/Assessment_category_format template and I don't intend to disparage it. But I'm wondering about the rationale of having on every single category page. MSGJ 15:10, 20 November 2008 (UTC)
The new template doesn't seem to do anything with the "field" parameter. Is this a bug? -- Trovatore ( talk) 22:11, 20 November 2008 (UTC)
We have a non-empty set of Category:C-Class mathematics articles. This category does not seem to be well integrated with the rest of the WP-math system. What should be done with this category? -- Salix ( talk): 11:19, 24 November 2008 (UTC)
259 articles link to The Wolfram Demonstrations Project, which redirects to Wolfram Demonstrations Project. Could people help bypass the redirect? Michael Hardy ( talk) 12:42, 1 December 2008 (UTC)
Thank you. I'll get to some of them myself later today unless someone beats me to it. Michael Hardy ( talk) 17:30, 1 December 2008 (UTC)
...I've done a dozen or so so far. Michael Hardy ( talk) 21:51, 2 December 2008 (UTC)
Anyone who is interested is welcome to contribute. Any comments/feedback (however minor) will be greatly appreciated.
Thanks, Topology Expert ( talk) 11:12, 20 November 2008 (UTC)
This is more like wish list, but it would be very nice if the article discusses closed-related topics such as Locally simply connected space or Semi-locally simply connected space. Also, the examples section should contain more concrete examples, examples familiar to non-topologists, if any. (I know very little topology, so I can't edit the article myself.) By the way, I really liked the intro; compactness implies locally compactness, but connected doesn't imply locally connected. This is probably basic but conceptually important, I suppose. -- Taku ( talk) 12:14, 27 November 2008 (UTC)
I am back from an unanticipated Wikibreak and I am extremely pleased with the changes made to the article. Thankyou very much to Plclark, geometry guy, Jakob and other editors for contributing. I will follow up on the comments by Jakob and geometry guy that have not yet been attended to. I will also respond more on the article's talk page but it may take until tomorrow. Just a note: after the recent changes, has the article improved to GA class?
The article mentions that an open subset of a locally connected space is locally connected and hence the same holds for Euclidean space. Plclark: your edits were very helpful but I feel that they are missing out on generality. For instance, originally I had written that an open connected subspace of a locally path connected space is path connected and now it is changed to the special case where the subspace in question is the whole space (and just an unrelated note that local path connectedness cannot be changed to local connectedness in the hypothesis of the theorem as a countable set given the cofinite topology shows; maybe this example could be added). I had earlier written that any linear continuum is locally connected and connected and now it is just restricted to R. I prefer generality rather than examples (prove that a weakly locally connected space is locally connected and then there should be no need to prove this for a particular weakly locally connected space). Anyway, this can be fixed (it will take sometime though) but until then, perhaps editors should stick to being general.
Thanks again.
Topology Expert ( talk) 15:25, 4 December 2008 (UTC)
User:JRSpriggs is attempting to sway a deletion process with Personal attack on physics project page. I removed the comment, but he reinserted it. Comment was added here: [4] and removed here: [5] and then reinserted here: [6]. Delaszk ( talk) 11:13, 28 November 2008 (UTC)
The article has now been deleted, but a Deletion review has been opened. Comments welcome. Geometry guy 21:19, 29 November 2008 (UTC)
This is not the only time that User:JRSpriggs has made a (false) personal attack to hide his misunderstanding/incompetence. See this and notice that JRSpriggs undid that edit because of his lack of knowledge (he did not even bother to read that section to see the counterexample mentioned as silly rabbit pointed out).
Topology Expert ( talk) 18:00, 4 December 2008 (UTC)
Thankyou for the apology but this is just my explanation as to why the placing was correct:
Topology and set theory are so closely linked that they are practically the same subject except for the fact that in topology you analyse a collection of sets satisfying certain axioms rather than analysing sets in general. So really, it would be strange for there to be no topology in an article on set theory and anyhow the theorem I included was proving the uncountability of the reals (shouldn't a reader be able to read as many proofs of this fact on Wikipedia as he wants?) (Wikipedia is an encyclopedia, yes, but you can't be so restrictive as to not include anything apart from what the article's subject is) (I certainly find any proof of the uncountability of the reals interesting).
But since the issue is not sorted out there is no need to discuss it again.
Topology Expert ( talk) 08:02, 5 December 2008 (UTC)
Stallings has recently passed away and this news is now spreading through the math community (see for example [7]) I put a current event tag on the article. Others may wish to watchlist the article for a time. -- C S ( talk) 21:46, 1 December 2008 (UTC)
User:WWGB insists on removing the recent death tag. Finally, s/he has given a reason: "not recent death". Does this make sense? Stallings has reportedly died on Nov 24. That would not only seem recent but since he is not a Britney Spears type celebrity, we can expect that the articles and information on his death will take longer to come out than a week or two. -- C S ( talk) 16:37, 5 December 2008 (UTC)
OK, I've finally added Stallings to the list of deaths in November 2008. I didn't do this earlier because I didn't know the precise date of death. In included a link to the Berkeley page announcing his death, and I notice that the Berkeley page includes a link to his Wikipedia article. Michael Hardy ( talk) 17:38, 5 December 2008 (UTC)
I have been working over on WP:DERM for a while, but am looking to work on the Gabriel's_Horn article, as I also have an interest in math. However, I am not as familiar with the WP mathematics policies, and wanted to know if someone could point me in the right direction. For example, I would like to expand the derivation of Gabriel's_Horn so that there are "smaller" steps. Would this be ok to do. Also, I do not notice any sources on that page. May I cite a mathemathics book within the dervation, or does math speak for itself? Thank you all for your help in advance! kilbad ( talk) 17:09, 2 December 2008 (UTC)
Any criticism about the Mayer–Vietoris sequence article would be appreciated. GeometryGirl ( talk) 17:47, 5 December 2008 (UTC)
And on that note there are a few suggestions at Talk:Vector space as to how the article can be improved. Improvements are welcome.
Topology Expert ( talk) 17:07, 7 December 2008 (UTC)
I know this is a kind of tall order, but i thought if i mention it, some people would possibly keep this in mind. There are some people, such as me, who don't really understand Algebra, but have an intuitive understanding of geometry. This means that if you explain something to me using algebraic notation, i won't understand a thing, but if you plot it on a piece of paper, I will most likely get it. I know I'm not the only one like that. Would it be possible, in the creation of new articles and the overhaul of older ones, to try to - in addition to the legions of formulas - give a geometric representation as well? Thank you very much for your time and effort, and for making wikipedia a more comprehensive resource - hopefully for everybody.-- ExpImp talk con 00:27, 3 December 2008 (UTC)
Having an intuitie understanding of geometry is very important to be able to do it (to do any math subject, you have to understand it intuitively; you can't just expect to write down the correct result from the top of your head). An image can help to illustrate a concept but an image is never a replacement for the formal definition.
Topology Expert ( talk) 18:06, 4 December 2008 (UTC)
The following points apply:
a) The _ looks ugly, yes. Therefore, we have LaTeX.
b) Commutative diagrams are images and I would accept that as a formal definition. But my point is that you cannot replace a formal definition with an image; not that you cannot add an image as an accompaniment to a formal definition.
Topology Expert ( talk) 08:07, 5 December 2008 (UTC)
Sometimes even when the semantics are ad hoc and informal, an image can be a much easier and still perfectly rigorous way of describing a mathematical object. Example: there exist 20 points in a 10x10 grid such that no three of the points are collinear. One can easily give a picture (right), which should be completely convincing. But describing those points in text (e.g. by giving their coordinates) would be tedious and error-prone. In fact, if I were given a list of 20 text coordinates and asked to verify whether they had this property, I think the easiest way to do so would be to draw the picture; I'd much rather do that than hand-enumerate all 2280 triples of points and go through a 3x3 determinant calculation for each triple to verify symbolically that they are non-collinear. — David Eppstein ( talk) 16:19, 5 December 2008 (UTC)
Yes proofs can use pictures (like many category theoretical arguments (I would classify a commutative diagram as a picture) or even the proof of the homotopy lifting lemma). In fact, I think that most people would prefer to prove simple facts like that the nth homotopy group of a space is actually a group by using pictures rather than giving a complex formulae for homotopies. Topology Expert ( talk) 15:52, 9 December 2008 (UTC)
Topology Expert ( talk) 20:42, 7 December 2008 (UTC)
You don't get it do you (for a start, the image constitutes a proof; not a formal definition)? Topology Expert ( talk) 15:52, 9 December 2008 (UTC)
Hello experts, some time last year there was some hullabaloo about repeated recreation, apparently by COI socks, of an article about so-called Boubaker polynomials. The consensus turned out to be there were no reliable independent sources establishing notability, and I closed the latest Afd ( Wikipedia:Articles for deletion/Boubaker polynomials (2nd nomination)) as "delete with prejudice against re-creation". Now, there is again a new editor, Luoguozhang ( talk · contribs), who has recreated Boubaker polynomials and a second, related article at BPES (guess what the "BP" stands for).
It does seem to me that he is now citing some independent sources, but I have no idea about the topic area and can't judge reliability. Can people with more topic knowledge please go and check if those articles are legit? Fut.Perf. ☼ 18:42, 6 December 2008 (UTC)
I've redirected it and deleted the links to it from the main article. Michael Hardy ( talk) 14:49, 7 December 2008 (UTC)
How can someone create so many sockpuppets?
Topology Expert ( talk) 15:57, 9 December 2008 (UTC)
I started editing the article dependent and independent variables, which was a real mess, and added some cited content under the math section. However, there is all this content under the statistics section that is uncited, and wanted to know if someone would help me find sources for this information, or challenge and remove it? kilbad ( talk) 03:12, 9 December 2008 (UTC)
We have dozens of links to the "Earliest Known Uses of Some of the Words of Mathematics" site, but this site has moved and the old links are now broken. The old URLs are of the form http://members.aol.com/jeff570/e.html and the new ones are of the form http://jeff560.tripod.com/e.html . Anyone who feels like updating some of these links can find them using the LinkSearch page. -- Zundark ( talk) 09:34, 9 December 2008 (UTC)
If anyone has some time, could they have a look at the Branch point article? It only gives an informal description before listing some examples, and finally mentions its usefulness and development in Riemann surface theory in the last couple of sentences, but again doesn't really give anything very concretely. I had a look at a few complex analysis books I had handy, and, well they tended to keep it pretty informal too, so I don't feel too confident having a crack at this myself. Cheers, Ben ( talk) 12:12, 10 December 2008 (UTC)
The concept is pretty basic in complex analysis (and in algebraic geometry) so I think you should have a go at editing it. After all, you should have a go. If at all you make a mistake, someone can easily correct it. I will add some examples to that page (and a proper formal definition for a start) and note that the branch point is defined only for holomorphic functions. Basically, a branch point of a holomorpic function (defined of course on the complex plane), is simply a point which gets mapped onto different values depending on its complex argument. Basically, a point z in the complex plane has countably many arguments (if its argument is θ, then its argument is also θ+2πn for all n in Z) and if the function value of z depends on the argument you choose, then z is called a branch point. The most obvious example of a function whose every point is a branch point is the function mapping a complex number to its argument. An example of a function with no branch point is the function mapping a point to its modulus. Think about this and have a go at editing the article. If I get time I will add a few facts myself.
Topology Expert ( talk) 13:46, 10 December 2008 (UTC)
Nope, they aren't. But I don't see why 'holomorphic' has to be included in the definition (as long as the functions are continuous and you can 'speak of' the change of a function along any path in the complex plane, that should be enough. And surely f is differentiable on any path in the complex plane?).
Topology Expert ( talk) 14:18, 10 December 2008 (UTC)
I added an equivalent (from the top of my head) definition to the article on branch point of a branch point of a function using the notion of a winding number. Anyone care to have a look at it (the second definition)? In my opinion the one I added from the top of my head is probably more mathematically formal.
Topology Expert ( talk) 14:20, 10 December 2008 (UTC)
The article (in the section on Riemann surfaces) writes the following:
The concept of a branch point is defined for a holomorphic function ƒ:X → Y from a compact Riemann surface X to a compact Riemann surface Y (usually the Riemann sphere). The function ƒ, unless it is constant, will be a covering map almost everywhere
This is meaningless in the sense that what does 'almost everywhere' mean. It can't be in the context of measure theory because there is no natural way (i.e to make a Riemann surface into a measure space such that the two structures are compatible) to make a Riemann surface into a measure space (forgive me if there is; I am not an expert on the subject). So what does it mean? Perhaps it (most likely) means that the map f is a covering map for all but a finite number of points but if so, this should be explicitly mentioned (and made more precise). Any opinions?
Topology Expert ( talk) 14:43, 10 December 2008 (UTC)
It also depends on what you consider a ‘covering map’ (i.e, whether you require a covering map to be surjective or not). But since the ‘result’ specifically excludes the constant map, it is probably not surjectivity (the constant map will yield a non-discrete fibre and hence cannot be a covering map).
Topology Expert ( talk) 14:55, 10 December 2008 (UTC)
I will copy this section there but let us continue it here because there are currently disputes regarding the material in that article (and hence we want as many mathematicians as possible to give their opinions). No one is going to go to the talk page of that article within a 100 years anyhow!
Topology Expert
OK
Topology Expert ( talk) 17:17, 10 December 2008 (UTC)
Is anyone else getting errors like this
on perfectly good LaTeX code every now and again? Is this something that the devs should be bothered with? siℓℓy rabbit ( talk) 22:24, 7 December 2008 (UTC)
The same thing just happened to me. Paul August ☎ 03:55, 9 December 2008 (UTC)
The "completeness relation" section in Hermite polynomials is not clearly written. Obviously whoever put it there was verbally challenged. I can't tell what it says. Not that I've exerted great effort on the point, but the meaning should be clear without that. Can someone help? Michael Hardy ( talk) 18:08, 11 December 2008 (UTC)
I may not have exactly got what is necessary (someone will have to fix up the LaTeX) but I basically only cleaned up the verbal bit (perhaps 'logically challenged' would be less insulting and more appropriate). Topology Expert ( talk) 20:27, 11 December 2008 (UTC)
Silly rabbit fixed up the LaTeX. How does it look now?
Topology Expert ( talk) 20:42, 11 December 2008 (UTC)
Please can any one tell me if these polynomials have any Exponential Generating Function and if their roots have any analytical expression ? (and please where can one find the Exponential Generating Function for Chebyshev Polynomials ?? Duvvuri.kapur ( talk) 22:32, 12 December 2008 (UTC)
New user Wayp123 has been adding a number of links to his/her website [10] and, after my deleting them, wishes to reinsert them. I don't see the notability of the site, but wanted to post here to discuss this in more generality (affected articles include matrix (mathematics) and linear map). Jakob.scholbach ( talk) 06:27, 8 December 2008 (UTC)
"New" user Wayp123 is in a strict sense not "new", since he was previously warned for spamming more than 2 years ago. But perhaps "new" in the sense of only having made intermittent spamming forays into Wikipedia and not really understanding how it functions. -- C S ( talk) 04:24, 9 December 2008 (UTC)
(ec) The principle behind Wikipedia, and the reason for its success, is WP:CONSENSUS. While consensus cannot usually be measured in terms of head counting, it seems quite easy in the case of this discussion. For inclusion: Wayp123 (1 editor, note WP:COI). Against inclusion: Jakob.scholbach, Paul August, RobHar, Hans Adler, C S, Salix alba, Silly rabbit, Msgj (8 editors). Please stop beating this dead horse. -- Hans Adler ( talk) 13:28, 9 December 2008 (UTC)
I think you are all paid wiki staff so I have no say. Wayp123 ( talk) 13:39, 9 December 2008 (UTC)
Neither do I. I just like to contribute for fun. Topology Expert ( talk) 17:05, 9 December 2008 (UTC)
Goodbye for now, Ill be back! Wayp123 ( talk) 13:50, 9 December 2008 (UTC)
That's an interesting point: On the survey, there was a question asking whether you are paid for editing Wikipedia (i.e Question: What is your reason for editing Wikipedia? and Choice: Because I am paid to do it). Maybe people are paid...
Topology Expert ( talk) 14:08, 9 December 2008 (UTC)
By the way, aren't C S and silly rabbit supposed to be on a wikibreak? (I couldn't resist myself either! I wonder whether anyone who put a wikibreak tag on his page has actually managed to pull it off...).
Topology Expert ( talk) 14:12, 9 December 2008 (UTC)
Oh, I nearly forgot: My daughter lost her gloves at the staff Christmas party last night. If one of you found it, could you please put it on my desk tomorrow? Thanks. -- Hans Adler ( talk) 17:50, 9 December 2008 (UTC)
Have you gone mad? (or is it just that I don't get the joke here?)
Topology Expert ( talk) 17:59, 9 December 2008 (UTC)
Current score: 9 paid Wikipedia staff members — 1 independent contributor who is only interested in improving the encyclopedia. -- Hans Adler ( talk) 21:44, 9 December 2008 (UTC)
To tell you the truth, I'd rather not hear about this party anyway.
Topology Expert (
talk) 11:00, 10 December 2008 (UTC) How do you know that I was not there?
Topology Expert (
talk)
20:05, 10 December 2008 (UTC)
I noticed that the day after the party, a team of plumbers were called to the venue. I am still baffled about this but I think it had something to do with the fact that David Eppstein was in the toilets for more than an hour. Topology Expert ( talk) 22:43, 12 December 2008 (UTC)
Please can any one tell me if the Boubaker polynomials have any Exponential Generating Function and if their roots have any analytical expression ? (and please where can one find the Exponential Generating Function for Chebyshev Polynomials ?? Duvvuri.kapur ( talk) 22:34, 12 December 2008 (UTC)
Please ask this at the reference desk. Topology Expert ( talk) 22:44, 12 December 2008 (UTC)
Thanks, we did not know the existence of this page..
Duvvuri.kapur (
talk)
23:39, 12 December 2008 (UTC)
The article on group actions contains a bit about orbit spaces (namely when a topological group acts on a topological space, one can consider the collection of all orbits as a quotient space) but such an important concept (namely the theory of Lie groups/topological groups acting on topological spaces) deserves its own article (I can explain its importance in mathematics if necessary). One very important application is:
I can create the article but I would appreciate it if some people could help out there (I am sure there are many applications which I would not know about).
Topology Expert ( talk) 15:08, 10 December 2008 (UTC)
Also there should be a proper article on orbit space. What would we call the article (namely the article describing the theory of topological groups/Lie groups acting on topological spaces) if we were to create it?
Topology Expert ( talk) 15:09, 10 December 2008 (UTC)
Yes, I forgot about orbifolds! But they really don't completely discuss the whole theory behind topological groups acting on topological spaces. Topology Expert ( talk) 09:15, 11 December 2008 (UTC)
Isn't anyone else going to comment on whether this idea is good or not? Or at least list some other concepts in this theory that they know? I think that there should be a category on this (just like there is a category:topology). Opinions (I am disppointed at the lack of enthusiasm when a subject related to topology is bought up. I know that there are lots of knowledgeable people on the subject (here) but most don't seem interested enough to comment. I once raised awareness that the article on fibre bundles is under par along with some (in fact a lot of) comments but no-one bothered to do anything until I personally asked some editors on their talk page)? Topology Expert ( talk) 14:17, 13 December 2008 (UTC)
You can get symbols inside a circle with oplus,ominus,otimes but how do you get symbols inside a square ? This is needed for the article gyrovector space. Delaszk ( talk) 16:27, 13 December 2008 (UTC)
A pair of editors have explicitly stated that they are in favor of deleting the article. It is of course their right to nominate the page for deletion. In the meantime, they are involved in edits that tend to degrade the quality of the article, in some cases based on ignorance of NSA. Can a case be made that if their intention is to delete it, they should refrain from further damaging edits so as not to predetermine the outcome of a deletion discussion? Katzmik ( talk) 08:18, 11 December 2008 (UTC)
I initiated a discussion on the talk page of the article (and gave reasons as to why I do not support the merge). Topology Expert ( talk) 21:50, 12 December 2008 (UTC)
Because I am supposed to follow the 'rules', I have copied the voting into the talk page of the article. Voting there is encouraged. Topology Expert ( talk) 22:26, 13 December 2008 (UTC)
(indent) Following the suggestions of numerous editors, the article has now been listed at AfD Wikipedia:Articles for deletion/Bishop–Keisler controversy. Mathsci ( talk) 05:28, 14 December 2008 (UTC)
I want to point out that if you merge this article into non-standard analysis, you should at least keep a redirect (not that I support the merge). Since this is a very famous controversy (as several users have pointed out), someone searching it should be able to go to its article and then be redirected. Deletion is simply ridiculous. Topology Expert ( talk) 11:09, 14 December 2008 (UTC)
I noticed that there seems to be a passive-agressive struggle in the edit comments of the Grothendieck article over whether he is Category:French people of German descent. Since December 7th, User:Feketekave and a few IP addresses (all similar, so probably the same unregistered editor) have been alternately deleting and re-inserting this category into the article, with Feketekave claiming it is "racialist" and the IP claiming that removing it is "vandalism". There have been now three rounds in this altercation, the two most recent being all four of the latest edits. These two need to be brought to heel and the issue should probably be discussed in the open now as well. I note that Grothendieck's ancestry and nationality have already been the subject of some debate, wherein his being Jewish (or not) was concerned. Ryan Reich ( talk) 17:15, 14 December 2008 (UTC)
Someone has been adding way too much to this category, and at the same time inexplicably missing obvious things like Dehn surgery. I wanted to post here for discussion before I start to unilaterally remove articles from the category. siℓℓy rabbit ( talk) 23:20, 5 December 2008 (UTC)
I undid silly rabbit's edit of removing homotopy groups from the Category:Surgery theory because they are used in surgery theory but I don't think they would be called part of surgery theory (an analagous case is the continuum hypothesis which is used in topology but not really part of it). Is this way of adding concepts to a category correct according to the Wiki conventions? I think that homotopy (and homology) groups are very important in surgery theory so because of this importance they should be included in the category but I would like another editor's opinion. Topology Expert ( talk) 17:00, 7 December 2008 (UTC)
Well, surgery theory does answer some questions in homotopy (and homology) theory regarding manifolds so I think they should be included. Topology Expert ( talk) 17:02, 7 December 2008 (UTC)
(unindent) OK, here is a question: should homotopy theory be included in Category:Fibre bundle and vice-versa? Any fibre bundle theorist will agree that the 2 are very closely related. Topology Expert ( talk) 11:26, 8 December 2008 (UTC)
It looks as though User:Ranicki has undone a few of my changes, adding things like Manifold and Lens space back to Category:Surgery theory. To me, this seems like overcategorization, as discussed above. I am going to again remove things from the category which do not belong there. siℓℓy rabbit ( talk) 15:20, 14 December 2008 (UTC)
I have never drawn commutative diagrams on a computer. The article commutative diagram contains pictures but no LaTeX. Could someone help me make the commutative diagram expressing the naturality of the Mayer-Vietoris sequence? Thanks, GeometryGirl ( talk) 20:53, 13 December 2008 (UTC)
I've just cut and pasted the follwoing from one of my LaTeX 2e files. It works perfectly well on there:
Failed to parse (unknown function "\begin{CD}"): {\displaystyle \begin{CD} R^2 \times R^3 @>\pi_1 >>R^3 @> f >> R \\ @V (A,B) VV @V B VV @VV \mbox{id} V \\ U \times S^2 \times I @>\pi_2 >> S^2 \times I @> g >> R \end{CD} } Δεκλαν Δαφισ (talk) 18:17, 18 December 2008 (UTC)
The "new user" User:Point-set topologist has added Wallpaper group to the category of mathematics Featured Articles, despite the fact that it seems not to be a featured article. It seems to me that this is a mistake; could someone more familiar with the GA/FA procedures confirm this? Plclark ( talk) 22:22, 17 December 2008 (UTC)
Are we now using C-class for the rating or not? I got the impression from Wikipedia talk:WikiProject Mathematics/Archive 43#Overhaul of assessment and project banner, at the bottom, that we're not. -- Jitse Niesen ( talk) 23:37, 17 December 2008 (UTC)
I added a request to put the recently featured article about groups on the main page. This system is a bit complicated, and the article being showcased probably depends on whether groups are "similar" to Emmy Noether, which was displayed on the main page some weeks ago. If you are interested in having a mathematics article showcased (and not the (n+1)st video game), please join in the discussion over there. Jakob.scholbach ( talk) 17:34, 26 October 2008 (UTC)
So what happened to this discussion? It is evident from the queue that the article will not appear on October 29th, that date that was proposed, but what decision was made ought to be available somewhere. Maybe with some archive of the discussion. Do things like that exist, or does the whole thing vanish from all memory? Michael Hardy ( talk) 01:22, 29 October 2008 (UTC)
Somehow, it did get selected quite soon (so, much ado about nothing from my part...), namely tomorrow, November 5. Perhaps people around can have an watching eye on it during that day. Jakob.scholbach ( talk) 07:52, 4 November 2008 (UTC)
Suppose ab=cd, suppose you let a=0 and c=0. Can you then write b/c = d/a ? Can you further say this is valid for all values of a and c ?
User:Bakken is claiming you can say these things because they are true in the limit.
See here: Talk:Lorentz transformation#There is nothing wrong in dividing by zero. Delaszk ( talk) 17:55, 3 November 2008 (UTC)
You are assuming that ab = cd. If a = 0 and c = 0 then b/c and d/a are not well defined. It is clearly true that if ab = cd then b/c = d/a provided that b/c and d/a are well defined, i.e. ac ≠ 0. Whenever we divide by zero we get a contradiction. Consider the famous example. Assume that x = y then after multiplying through by x we get x2 = xy. Subtracting y2 from both sides gives x2 - y2 = xy - y2 . Which, after factorisation gives (x + y)(x - y) = y(x - y). Dividing through by x - y gives x + y = y. Assuming that x = y gives 2x = x, and finally dividing through by x gives 2 = 1. Clearly 2 ≠ 1, and so we have a contradiction. The contradiction came from dividing through by x - y and then assuming that x = y, i.e. dividing through by zero. I don't think that projective space is involved here. If it were to be, and the person posing the question knew that it was, then the question wouldn't be posed in the first place. Be careful of limits. Limits and equalities are not the same thing. Δεκλαν Δαφισ (talk) 23:07, 3 November 2008 (UTC)
Bakken, you say that "You cannot avoid a genuine singularity in a physical system by mathematical transformations." What about the simplest case of the the transformation T(f)(x) := exp(f(x)). Let the function f be given by f(x) := -1/x2. It follows that the transformation of f is smooth and well defined for all x; T(f)(x) has no singularity at all, but f had an honest singularity that can not be removed by any change of coordinates. Δεκλαν Δαφισ (talk) 10:59, 5 November 2008 (UTC)
A web site about tangrams; sorry if it's off-topic, but the article makes a lot of references to math software. VG ☎ 02:28, 6 November 2008 (UTC)
I recently came across the article Vector resolute, which is also known as vector projection. I had not heard of this terminology before. Googling the term "vector resolute" turns up about 709 results, and the term "vector projection" turns up about 13,000. I would like to change the article from vector resolute to vector projection, as I see it as the more common term, and move the links so that it points the other way. I cannot decide if this would be inappropriate behavior, so I thought I would ask first. Thenub314 ( talk) 07:39, 6 November 2008 (UTC)
OK, I've moved it, and I've fixed the link from template:linear algebra. If you go to vector projection and click on "what links here", you may find many links to the redirect, but most of those will be shown as direct links to vector projection after my edit to the template propogates (if I'm right in guessing that most links to that article result from the template). In 24 hours or so, if you click on "what links here" again, you'll see the actual links to the new redirect page, and then those can be fixed. Michael Hardy ( talk) 19:12, 6 November 2008 (UTC)
This template should probably be updated to include the full range of quality and importance categories. For example
List of International Mathematical Olympiads is a featured list but the FL link on
Talk:List of International Mathematical Olympiads is currently was red.
MSGJ
14:09, 6 November 2008 (UTC)
It now appears that group (mathematics) will be "Today's Featured Article" on the main page very soon (tomorrow?).
But there's a glitch: The image of Rubik's Cube featured prominently right at the top of the article is proposed for deletion. The argument is that it's a copyrighted work and therefore any photograph of it is a "derivative work". And people who are not aware of the relevant facts or of copyright law are participating in the discussion, urging deletion. The discussion is [ here]. Michael Hardy ( talk) 16:45, 4 November 2008 (UTC)
I don't think that's a good resolution. That image has been there for a long time, and nobody challenged it until it got schedule to appear on the main page in a day or two. Why is that? Michael Hardy ( talk) 16:54, 4 November 2008 (UTC)
Unfortunately the vandals are winning, even if they fail to get the image deleted. They will probably prevent its schedule appearance at the top of the main page.
We need to find a good image quickly. The snowflake image is distinctly inferior, and I don't mean just as a work of visual art. It is inferior as a means of illustrating the mathematical idea that this is about. Michael Hardy ( talk) 17:17, 4 November 2008 (UTC)
OK, you don't like my style. But what about my actual point: We need to find a good image fast. Michael Hardy ( talk) 18:15, 4 November 2008 (UTC)
There's something to be said for Alexander's Star, but I think the Rubik's Cube picture much more clearly convey's the idea of transforming by turning one side, and that's what corresponds to the group's binary operation. Michael Hardy ( talk) 21:42, 4 November 2008 (UTC)
Just wait until the preacher says "Speak now or forever hold your peace" to bring up something that could have been dealt with privately earlier, so you can make a public show of humiliating people to punish them for good work. That's what's happened here. This will be remembered for a long time. The story of this incident will be the whole content of the comprehensive biography of the persons responsible. A hundred years after the deaths of that person, or those persons (I don't really know who or how many), this is what they will be remembered for. This is all that they will be remembered for. Michael Hardy ( talk) 01:11, 5 November 2008 (UTC)
I thought the article actually discussed the 3x3x3 cube's group. Since it doesn't, there are a number of images that are not of the 3x3x3 cube. It looks like the 4x4x4 cube is not produced by the same lame company [1], so I don't see an immediate problem, as there's no obvious copyright claim on the web to poke us with. BTW, a number of free screen savers use the 4x4x4 and 5x5x5 cube, but don't offer the 3x3x3 cube. I think I've figured out why :) VG ☎ 01:37, 5 November 2008 (UTC)
Looks good. user:r.e.b.'s recently installed picture is better than the snowflake, but these Rubik-type things actually illustrate the motions. Can we get this installed fairly quickly? Michael Hardy ( talk) 02:57, 5 November 2008 (UTC)
If anyone here has a moment or two, please comment on the Proposed Changes thread at talk:Monty Hall problem. -- Rick Block ( talk) 03:48, 8 November 2008 (UTC)
Is there any point to this article or can it be deleted, redirected or merged? I'm not a maths person so I don't know. Cheers — Realist 2 13:29, 7 November 2008 (UTC)
I've added some context and links to make the article more readily comprehensible. The user who created it also created a bunch of other severely stubby articles about gears with no initial context-setting. One of them read as follows (the whole article):
I'd have thought that was about dentistry rather than mechanical engineering (the article has improved since then). Michael Hardy ( talk) 02:32, 9 November 2008 (UTC)
Is there a way to label an equation or something à la
and have a label somewhere else ("equation (1)")? The link, much the same way as one has footnotes, should be such that if the reader clicks at the link, the equation or at least the label at the eqn. is highlighted in light blue. Jakob.scholbach ( talk) 20:40, 7 November 2008 (UTC)
Another contributor to the Exponentiation article wants to change it in a way I believe is very much against the ethos of an encyclopaedia. The latest discussion is at Talk:Exponentiation#exp(x). The other contributor Bo Jacoby ( talk) is not about to go away soon, he has been trying to change various things in the article for the last three years. Is there a way of mediating or coaching so the exchange is a bit more fruitful, or do you judge that would be fruitless and the rumbling is at a low enough level that it can just go on for then next few years - or have you any other ideas for a more productive use of time? Dmcq ( talk) 13:32, 8 November 2008 (UTC)
There is currently (or more rather a two years old) merge discussion on its talk page. Could an administrator please sort it out?
Topology Expert ( talk) 08:40, 8 November 2008 (UTC)
Correction: The merge discussion is 11 months old (initiated by User:Arcfrk)
Topology Expert ( talk) 08:42, 8 November 2008 (UTC)
The second of these three articles is mostly about comparametric plots. That part of it should get merged into comparametric equation. Michael Hardy ( talk) 02:59, 9 November 2008 (UTC)
I have created the article titled Regiomontanus' angle maximization problem. Probably it could profit from other points of view. Everybody's seen this problem in a calculus course, but I think it is far less well known that there's a simple solution via elementary geometry. In addition to those two, I've included a solution by simple algebra. Michael Hardy ( talk) 03:02, 9 November 2008 (UTC)
Topology Expert ( talk) 11:31, 9 November 2008 (UTC)
Thank you. I'll cite at least one textbook. Michael Hardy ( talk) 02:27, 10 November 2008 (UTC)
A new editor, user:Xzungg, is repeatedly making some POV edits to Skolem's paradox. I have integrated the positive parts of his edits into the article already, and commented on the talk page. I could use the assistance of a couple other editors to help determine a consensus about the article content. — Carl ( CBM · talk) 14:20, 9 November 2008 (UTC)
I have nominated the biography Kevin Houston for deletion at Wikipedia:Articles for deletion/Kevin Houston. Please feel free to comment there, but please use tact, since the discussion is public and there's a decent chance Houston may read it someday. — Carl ( CBM · talk) 14:29, 10 November 2008 (UTC)
Hi,
This is Bill Wedemeyer, a biochemistry professor at Michigan State University. I apologize that this message is not directly related to mathematics, but please bear with me for a moment. I've come to ask for your help, especially the help of my fellow professors.
I recently became aware of The Core Contest, which was run last year for a few weeks (Nov 25 – Dec 9). Briefly, it was an article improvement drive focusing on basic articles that belong in the "core" of an encyclopedia, with awards of $100 promised for the five most improved articles. For example, one of the articles was Hypatia of Alexandria, which belongs to this WikiProject.
My impressions are that (1) the contest was remarkably successful in improving articles and (2) many younger students threw themslves into it, body and soul, partly for the fun of it but also in the hopes of winning the prizes. Unfortunately, circumstances seem to have conspired to prevent those prizes from being awarded.
I'd like to amend this and reward the prizes, as they were promised. I'm willing to sponsor the awards myself, but I hope you agree that it'd be more fun and more wiki-spirited if we all joined in. I'm especially interested in recruiting professors, who I think will want to be kindly to poor but hardworking students, especially in this season of many holidays. We probably all remember what it was like to be a poor student.
I've contacted Prof. Martin Walker (one of the judges of the contest) about the matter, and he's very supportive. Please contact me by e-mail if you're interested in donating to the cause. We would plan on announcing the winners in two weeks, on November 25th, the anniversary of the contest.
Thank you, Proteins ( talk) 18:31, 10 November 2008 (UTC)
I'm glad that the first responses are so positive, and that people aren't mad at me for posting something off-topic. It's true that writing good articles about topics so vast in scope is hard, although it's also true that many might benefit from such articles. I don't mean to say that these articles are more important, or more crucial to the success of Wikipedia than, say, group (mathematics). As a professor, I think my own articles would have to be specialized, too; by report, professors' knowledge has increased and their scope narrowed so much that they know practically everything about practically nothing. ;) My interest in the Core Contest is purely personal. It pains me to see students working hard and then disappointed, and I suspect that others will want to join me in setting things right. Proteins ( talk) 19:43, 10 November 2008 (UTC)
PS. My special thanks go out to Prof. Tsirelson, the first person to write me and volunteer his help!
Proposed, anyway. It's not categorized yet, but would be somewhere in Mathematics. — Arthur Rubin (talk) 15:16, 7 November 2008 (UTC)
As for this article, sure, let's delete that. However, to take us slightly off topic, let me point out that the theorem that the kth-root of a natural number n that is not a kth-power is irrational is of significance historically. For example, Theodorus claimed to have proven the square root of n (except 4, 9, and 16) up to 17 is irrational, and explanations of how he could have done this form a non-negligible body of scholarship. Part of the speculation rests on the assumption that he did not know the fundamental theorem of arithmetic. Indeed, as pointed out in Hardy and Wright's text on number theory, the fundamental theorem of arithmetic is not required for the proof that kth-root of a natural number n that is not a kth-power is irrational. Elementary methods analogous to that of proving square root of two is irrational can be used. -- C S ( talk) 21:06, 7 November 2008 (UTC)
...are things that sit there for LONG periods of time with no attention from anybody. For SEVERAL YEARS now, this has sat in the article titled Gottfried Leibniz:
y = x. That's what it said. The graph of that equation is a straight line; the area under it is the area of a triangle. Obviously Leibniz was not the first to find the area of a triangle; obviously you don't need integral calculus to do that. I've changed it to read as follows:
Note that I changed "the" to "a". Several years ago, this got quoted on the main page and consequently ridiculed here on this page, and then it got fixed on the main page. But not in the Leibniz article. People may argue about whether Archimedes' various quadratures that anticipate Leibniz's work but did not use the fundamental theorem of calculus mean that the words "for the first time" are right. But the part where it says y = x is so idiotic that one should wonder: is there some way of making the process of bringing Wikipedia's content before the eyes of knowledgeable people can be made systematic enough that glaring things like this will be seen? Michael Hardy ( talk) 22:40, 11 November 2008 (UTC)
If the article was correct, it really needs to get phrased differently from the way it was. Michael Hardy ( talk) 04:36, 12 November 2008 (UTC)
I understand what you mean. It is sometimes frustrating to have an article where absolutely no-one bothers to read or add to the discussion page. If I post a comment one day, I probably won't get a reply for at least a year. But I have to deal with it. That is why most of the time I follow the following:
a) If it is a 'popular' article to edit, I comment at the discussion page and someone will probably see my comment within a week and respond.
b) If it is unlikely that someone will ever respond to my comment (if I make one), I will probably just make the edit I want to anyway (saves a lot of time and trouble).
Maybe there should be some sort of way of monitoring a page (other that watching) that involves a group of editors who discuss changes to the page in question quite often. On each page we could have a list, and editors could add themselves to that list provided that they monitor that page frequently (at least once per month). If many editors participate in this 'project', they could be evenly distributed over most of the math articles. I don't know whether this is a good idea but I think it is at least a slight improvement compared to the features we have now.
Topology Expert ( talk) 13:55, 12 November 2008 (UTC)
Occurrence-in-subtuple problem has been "prod"ed. Does anyone know anything about this? Michael Hardy ( talk) 13:51, 15 November 2008 (UTC)
The vector space article currently says: "The ultrafilter lemma, which is weaker than the axiom of choice, implies that all bases of a given vector space have the same "size", i.e. cardinality. citation needed" Can somebody provide a reference for this, please? I didn't find one. Thanks, Jakob.scholbach ( talk) 14:25, 15 November 2008 (UTC)
In the "solution by algebra" section in Regiomontanus' angle maximization problem, I've put in a show/hide button that's not working. Can anyone figure out why? Michael Hardy ( talk) 20:16, 10 November 2008 (UTC)
Why I want to do it would be clear from what I wrote there, I would think. I know others have done this in various other math articles. Has this problem occurred elsewhere? Michael Hardy ( talk) 22:06, 10 November 2008 (UTC)
It's not about hiding "boring derivations"; it's about hiding things that interrupt the main line of argument that is the point of the section or paragraph or passage, but that might nonetheless be of encyclopedic interest.
Also we have a policy requiring articles to be accessible to a broad audience. This furthers that policy. Michael Hardy ( talk) 03:36, 11 November 2008 (UTC)
I actually like the idea of the show/hide button. It is something an online encyclopedia can do but which a paper one cannot do, so it should be exploited! There are many cases when a casual reader would not want all the details of a proof/derivation, but someone really trying to understand the topic would want to read. MSGJ 17:45, 11 November 2008 (UTC)
I also changed this template to the one User:Ben Tillman put instead of the previous algebra stub template. Again this is more representative of number theory (and that is why I changed it (I don't really think having the numbers 0,1 and 2 is useful although 1 and 0 may have some (slight) significance)). Hopefully there are no objections but if you have any, please post them and I can discuss.
Topology Expert ( talk) 05:56, 16 November 2008 (UTC)
Does anyone else have an opinion on this?
The former, using \emptyset, looks like something that shows up because you're using an old-fashioned typewriter with a correspondingly limited character set, so you type the digit 0 and then backspace and type a slash over it. So I prefer the latter, using \varnothing. Michael Hardy ( talk) 19:17, 16 November 2008 (UTC)
Is there really no choice of font? When I make an \emptyset in pdflatex, on my own LaTeX installation, it comes out nicer than the one here. See this screenshot: . Aspect ratio seems to be about 3:2 (not counting the slash) whereas the WP one is more like 2:1, which seems too much. -- Trovatore ( talk) 07:01, 17 November 2008 (UTC)
Is there a way of forcing a character to be bigger or smaller in tex on WP? I tried out \large and some options in \mbox but it complains about anything I do. I notice for \varnothing people were getting screen images to make it larger so I guess it's not possible, but my reading of tex says I should be able to do something like \mbox{\large 0} but I can't get anything along those lines to work. Dmcq ( talk) 15:26, 17 November 2008 (UTC)
Occurrence-in-subtuple problem, an article about a combinatorial problem said to have applications in genetics, has been nominated for deletion. It is obvious that the reason for some of the imperfections in writing is that it was written by someone who is not a native speaker of English. That of course is a reason to clean it up, not to delete it. The substantial objection seems to be an allegation of original research, concerning which I have no settled opinion. Michael Hardy ( talk) 05:11, 18 November 2008 (UTC)
Can someone provide precise statements of the theorems of Kolmogorov and Arnold that are mentioned in a hand-waving way in Hilbert's thirteenth problem? Some sources on the web speak of "superposition", which I usually think of as meaning addition, but some other speak of "composition", which I usually think of as something quite different from addition. The Wikipedia article ought to give a precise statement of the problem if possible. Michael Hardy ( talk) 06:11, 18 November 2008 (UTC)
I have seen the template:
(removed now that discussion is over becase otherwise this page would be classified as an 'algebra stub' once archived)
on several pages and I was wondering whether this template could be changed (this maybe a bit difficult and I don't know the rules so I am assuming that this can be done). The reason being is that it does not really reflect what 'algebra (modern)' is; rather it reflects high school algebra. Maybe in a way it reflects field theory (in a vague way!) but it does not reflect group theory very well. I think that there could be a more 'representive' symbol. Any opinions?
Topology Expert ( talk) 11:20, 9 November 2008 (UTC)
But I am not sure that fifth-graders are supposed to understand this. Moreover, a fifth grader would probably interpret the symbol as 'high-school algebra' (which is rather reasonable for someone who has never heard of the subject). Perhaps we could still make it 'easy to understand' and 'representative of modern algebra'?
I agree with what User:Delaszk said because the most appropriate symbol would probably be one that reflects the fundamental idea behind group theory (and that is of course the binary operation). Could we implement this or do we need more people to agree?
Topology Expert ( talk) 00:50, 10 November 2008 (UTC)
Topology Expert ( talk) 07:57, 10 November 2008 (UTC)
Could someone please tell me how (and I could do it)?
Topology Expert ( talk) 07:39, 15 November 2008 (UTC)
I'm just wondering why these stub templates need images at all. Would not
suffice. What encyclopedic purpose does the image really serve, they just take up screen space and distract the eye.-- Salix ( talk): 08:22, 16 November 2008 (UTC)
As I have mentioned already, a simple image such as sqrt(x) or a^n + b^n = c^n is representing the wrong field of maths (one representing arithmetic and the other is representing number theory). I can get a different image and try it out, perhaps, if other people also disagree entirely with this image. But I think (and I hope others do to) that we need a proper image and all the previous ones were not at all satisfactory.
Topology Expert ( talk) 09:55, 16 November 2008 (UTC)
Take the current {{ Cattheory-stub}} template which is basically (not mathematically) the same as this one.
Topology Expert ( talk) 09:58, 16 November 2008 (UTC)
What about this one:
that illustrates the compatibility of two different structures on a field (that make it into a bialgebra). If not this one, I would say that the following image could also work (quite a simple commutative diagram that illustrates the associativity of monoids (assoicativity is something that a fourth grader could understand)):
Any opinions?
Topology Expert ( talk) 10:42, 16 November 2008 (UTC)
Unfortunately, no one seems to understand my point. My point is that we want something that represents modern algebra. Not some junk like a square root symbol that makes an ordinary person believe that mathematics goes as far as a square root (and believe me, there are people who think this). Furthermore, this is not the sole purpose of the image. We also want the image to represent a fundamental idea behind group theory. I do like the image given by Jakob.scholbach, but a cube does not represent the fundamental idea behind group theory. A concept such as the binary operation or a commutative diagram that illustrates the compatibility of two different structures on a field would really represent this field of mathematics better (the binary operation would be the best). If you want something easier to understand (now lets face it, there are mathematicians who don't know much group theory (or category theory)), then choose something like this:
This commutative diagram represents the associativity of the binary operation in a monoid (which would be understood by any real mathematician). We definitely can't (and don't want to) aim for an average (non-mathematician) to understand the image; we want the image to be understood by someone who has had some decent formal training in mathematics (or who is learning group theory). And anyone who knows what a function is would probably understand a (simple rectangular) commutative diagram.
So if you don't like the current image, the one I just suggested may be better. Any opinions? If there is still disagreement, I can try for another image but I would like to have the opinions of several mathematicians.
Topology Expert ( talk) 12:21, 16 November 2008 (UTC)
Thanks for the opinion. What I don't understand is why we can't make the image 100px which is not too large and is still (reasonably) visible to the naked eye:
Why wouldn't this work?
With regards to algebra and category theory, I am quite confident when I say that category theory was invented based on algebra and then expanded to other fields of mathematics. For instance, 'isomorphism' is common to both fields and I can list quite a few others which are active terms in algebra as well as in category theory. If you analyse the commutative diagram carefully, it basically illustrates (the fact) that in a monoid, the binary operation is associative.
Topology Expert ( talk) 12:57, 16 November 2008 (UTC)
As I mentioned earlier, one cannot decipher what the current category theory stub template is about either ({{ Cattheory-stub}}) but that has been there for a long time. At least 100px is visible and not too large. Why in Wikipedia, does everything have to follow strict rules?
Topology Expert ( talk) 12:59, 16 November 2008 (UTC)
I agree with what you say about the importance of the image. But at least this image is better than sqrt(x) and I bet that someone who knows calculus could easily learn what a commutative diagram is. Furthermore, we don't expect everyone to understand it; as long as an algebraist can understand it, its fine. The image should just be a representation of the field and not part of an article, so people are not expected to understand the image.
Topology Expert ( talk) 03:45, 17 November 2008 (UTC)
Topology Expert ( talk) 06:05, 17 November 2008 (UTC)
I can't believe there's serious debate over whether abstract algebra should be represented by a 75px image of a commutative diagram, no matter how algebraic the fact it encodes. The idea, in addition to being absurd from a visual design perspective, borders on the snobbish: why does the stub template have to represent some fact of "real" math, one phrased in a language that, admittedly, is not understood or appreciated by most students and a good number of practitioners? Anyone who sees this stub, however amateur at algebra, should understand that it's talking about something they might know; ask yourselves if, as undergraduates, you would have had that reaction to the associativity square. I think this point is amply supported by Topology Expert's own words: if a calculus student could "easily learn", or someone familiar with functions could "probably understand" a commutative diagram, then it is too complicated; we should not be arguing over whether the picture is potentially comprehensible, but whether it is thematically suitable. We may not care whether non-mathematicians get it, but we had better not be so elite as to dismiss college students (or, God forbid, analysts :) ).
Furthermore, category theory is totally unnecessary for understanding what algebra is about, and writing associativity as a commutative diagram is obfuscatory unless there's a more general game afoot. Granted, saying "algebra is square roots" is rather a dumbification, but not every level of abstraction below the One True Abstraction gives a misleading picture of the subject. Algebra, in itself, is a subject concerned with sets, elements, and operations, not objects and arrows (however much about the former they reflect), and understanding it at just that level is enough to, say, get you a Fields Medal, if you do it right. Ozob's suggestion is an excellent one: it expresses a fact basically characteristic of algebra (if you see a binary operation, and it's associative, then you are in the midst of defining an algebraic structure) in a concise way that, if you learned any algebra at all, you learned this first. Ryan Reich ( talk) 01:23, 18 November 2008 (UTC)
Topology Expert ( talk) 04:05, 18 November 2008 (UTC)
Also, category theory is the centre of mathematics and every single branch of mathematics has objects and arrows anyhow.
Non-associative algebra may still be algebra but you will have to agree that associativity (except for closure of course) is the most fundamental axiom in algebra.
Topology Expert ( talk) 04:38, 18 November 2008 (UTC)
Take this massive comutative diagram for instance:
How else would you describe what a Hopf algebra is (unless you want to tediously find a series of equations that are equivalent to this commutative diagram)? Commutative diagrams are a easy (and natural) way of storing information and are everywhere in advanced mathematics. I am probably telling you what you already know, but my point is that you shouldn't be afraid to include a commutative diagram in a supposedly 'lower level' mathematics like algebra. Furthermore, I can also bet you that everyone who knows algebra well, will also know what a commutative diagram is. Isn't that what we want?
Topology Expert ( talk) 06:44, 18 November 2008 (UTC)
Topology Expert ( talk) 02:00, 19 November 2008 (UTC)
(By the way, associativity is to groups as Hausdorff is to topological spaces. Many mathematicians don't care about non-Hausdorff spaces but that does not mean that Hausdorff spaces are unimportant).
Topology Expert ( talk) 03:28, 19 November 2008 (UTC)
Why would you think that is boring? When I first learnt about these infinite cardinalities, I was fascinated (and excited to prove by myself that ).
Topology Expert ( talk) 03:35, 19 November 2008 (UTC)
Topology Expert ( talk) 05:15, 19 November 2008 (UTC)
Great! I just thought of something much better (represents algebra well, very easy to understand, and also quite important)! What about an exact sequence? We could choose a simple sequence consisting only of three objects. For instance:
Practically everyone knows that represents the integers and practically everyone has a vague idea as to what the arrows are (a function). This would be more exciting as an image, more concise, and much better than a dinosaur commutative diagram. Any opinions on whether or not this would be preferable to a commutative diagram?
Topology Expert ( talk) 05:28, 19 November 2008 (UTC)
As I mentioned, we want to expand people's knowledge (one purpose of Wikipedia) and this stub template is excellent for this (allows people to learn about the mathematical subject of category theory).
Topology Expert ( talk) 05:46, 19 November 2008 (UTC)
Well, if I were feeling cynical, I could point out that most of the students in a course I'm teaching never heard of Euclid until I mentioned his name (I don't know how you can do that and be a high-school graduate) and they certainly don't know what the blackboard bold letter Z represents. And guess what they "know" that the arrows mean? Here's an example:
That what "almost everybody knows" the arrows mean. Michael Hardy ( talk) 05:54, 19 November 2008 (UTC)
There are two things that I have learnt in the past 10 days:
a) Wikipedia can be a big waste of time sometimes (good fun though)
b) The world is a lot dumber than I thought
(you must really get sick of teaching your students; I don't know how you do it)
Topology Expert ( talk) 06:31, 19 November 2008 (UTC)
The Rubik's cube has the following flaws:
1. It is too colourful and gives the wrong impression of mathematics (people may think that to solve a Rubik's cube, you need to be good at maths and if you can solve it, you must be the best mathematician around (believe me, people think this already; we don't want to give them encouragement)).
2 (more importantly). It only represents finite group theory and does not have a wide scope. One user mentioned that the commutative diagram only represents associative algebra; at least it represents a wider scope of algebra compared to the Rubik's cube.
Any arguments against my points? (some support would be much appreciated)
Topology Expert ( talk) 08:06, 19 November 2008 (UTC)
Because of the apparent stupidity of the outside world, I want to make a point that this template should only be aimed at real mathematicians (any mathematician knows what an exact sequence is (or at least what an arrow means (or Z (hopefully)))).
Topology Expert ( talk) 08:11, 19 November 2008 (UTC)
a) Give an image which people (who don't know maths) are clueless about so they stop talking nonsense
b) Give an image which is really important in the intersection of mathematics with algebra
Commutative diagrams are wonderful for both purposes. As I mentioned, the image that User:Ozob suggested is mathematically equivalent to the commutative diagram and furthermore, gives more meaning to mathematics.
You are probably sick and tired of me arguing so I won't argue for so long. I just wanted to emphasise that:
a) The Rubik's cube is unsatisfactory (in my opinion) for the reasons I have already mentioned
b) User:Ozob's image is mathematically equivalent to mine
(You probably don't want me arguing any longer and as you said, it doesn't matter what image we choose; the words are more important. Since no one (except for me) is going to analyse the image, we might as well keep the commutative diagram unless of course it discourages people from expanding a stub (which is unlikely)).
I just wanted to make one quick (and very important point); algebra is a subject which almost any mathematician (and student) knows at least a little bit about. Therefore (with the number of algebraists around), any algebra stubs must contain really deep concepts within the field (because very few people would have known enough to expand it and hence it is a stub). So really, anyone who can expand an algebra stub, will probably know algebra well and hence what a commutative diagram is. The more simpler concepts can be edited by college students because they won't be stubs (generally between stub and good article mostly).
Topology Expert ( talk) 12:45, 19 November 2008 (UTC)
Also (to Brwian), category theory is very important in mathematics (see category theory and perhaps homological algebra for an example). Topology Expert ( talk) 12:54, 19 November 2008 (UTC)
To Brwian: what about sheaf theory?
Topology Expert ( talk) 02:54, 20 November 2008 (UTC)
OK, so there are a few basic concepts which are stubs. If I make them 'unstubs' now, we can accept the commutative diagram? I will start with trinomial.
Topology Expert ( talk) 02:58, 20 November 2008 (UTC)
( edit conflict) Most of the users have bailed this discussion so I think the vote is pretty much, 'who cares', although some users still strongly hate the commutative diagram. My point is that the commutative diagram encourages editors to learn about category theory. Have a look at this and you will find that the template is more descriptive and people will not think that it is a smudge anymore. Furthermore, the new description encourages readers to learn about category theory: a bonus because anyone who knows calculus (well, unlike Michael Hardy's students) will be able to learn the basics of category theory.
Topology Expert ( talk) 03:50, 20 November 2008 (UTC)
Topology Expert ( talk) 04:06, 20 November 2008 (UTC)
Topology Expert ( talk) 04:49, 20 November 2008 (UTC)
I have a better idea. There was no agreement over which image to use (some people liked the rubik's cube, some preferred the associative rule, some people don't give a monkeys). However there does seem to be consensus that the image is not very important - it's the text that is important. So I have removed the image and just left the text. I agree this discussion has gone on far too long. TE it is understood that your intentions are entirely good; however you should have realised earlier that your opinions were not gaining support. MSGJ 09:53, 20 November 2008 (UTC)
Topology Expert ( talk) 11:17, 20 November 2008 (UTC)
So in TE's style, please type below: (No reasons/discussion required, thanks.)
Votes will be counted tomorrow. MSGJ 19:12, 20 November 2008 (UTC)
Topology Expert ( talk) 23:53, 20 November 2008 (UTC)
I know that I am alergic to stub templates but how about this one:
Since most people here want a 'geometric' image of group theory, this one is perfect. It is also quite clear and reperesents the circle as a group (in fact a Lie group; the circle is one of the most common, simple examples of these).
What Delaszk said explains something: algebra has a lot to do with category theory (and as I mentioned, category theory originated from algebra (hence the term 'isomorphism')). Maybe one day, category theory will be a huge part of algebra (galois theory, in my opinion, is a mix of category theory and algebra!).
Topology Expert ( talk) 01:14, 21 November 2008 (UTC)
How does this look?. I suggest looking at:
before judging (every college student who does algebra will know that the circle is a group with multiplication).
Topology Expert ( talk) 02:36, 21 November 2008 (UTC)
Huh? On Locally finite group and Affine Grassmannian, the associativity equation appears but on Trinomial, no image appears! There must be an error because of so frequent changes (or maybe it just comes up like that on my computer).
Topology Expert ( talk) 02:41, 21 November 2008 (UTC)
I have nominated the vector space article for WP:Good article nomination#Mathematics. I'd be thankful if people around could have a look, particularly those knowledgeable in analysis. Jakob.scholbach ( talk) 09:28, 18 November 2008 (UTC)
P.S. There are two other current nominations (nominated by other editors), Mayer-Vietoris sequence and Robert Hues. I'd like to encourage people to review articles. It's fun, usually pretty interesting and helps the author of the article a lot. Thanks, Jakob.scholbach ( talk) 09:36, 18 November 2008 (UTC)
Topology Expert ( talk) 07:54, 19 November 2008 (UTC)
First:
Second:
First, within "math" tags:
Second, within "math" tags:
At radius of convergence, this first form was failing to get rendered. Why? Michael Hardy ( talk) 23:30, 18 November 2008 (UTC)
The problem seems to have been fixed. I edited the article and it looks good now. Michael Hardy ( talk) 18:14, 19 November 2008 (UTC)
DYK has started keeping track of which article have received the most page views while being featured on the Main Page. See Wikipedia:DYKBEST. DYK would like to make its section of the Main Page more effective. We are in need of Wikipedians who can review the raw Wikipedia:DYKBEST data and come up with factors that make it more likely that an article will receive page views. If interested, please feel free to review the data and edit Wikipedia:DYKBEST#Features_of_an_effective_DYK_hook. Thanks. -- Suntag ☼ 08:22, 20 November 2008 (UTC)
Don't fear the heading; wait till the end of my message. A non-mathematician keeps reverting my changes to this but I found a perfect image. To make this discussion short, have a look at this. Then type either 1 (for agree with my image) or 0 (if you disagree). No explanations required. If my image is not favourable (after 5-7 people vote), I will immediately revert my inclusion of that image. Please decide on the basis of the image rather than the previous discussion and also note that my image represents the connected sum (differential geometry). Anyone can understand that the image illustrates two objects being glued together and furthermore, this is more representative than a dodecahedron.
Topology Expert ( talk) 11:49, 20 November 2008 (UTC)
If necessary, the image size can be increased by a few pixels and this should make it more clearer.
Topology Expert ( talk) 11:51, 20 November 2008 (UTC)
Ok (you don't have to say sorry by the way). First of all, I had a dispute with User:Moondyne regarding something else and he threatened to block me. Next, he started tracing my edits and reverting them (these edits were mathematics-based). I didn't mean to be rude, but I am trying to expand Wikipedia. If users threaten to block me, be rude ( User:Moondyne), don't agree with me (I think users are against me now but I can't do anything about it) and undo my edits, then it seems that it would be best if I retire. And I know that no one really would care if I retired (I have better things to do anyhow (as everyone here does)). I also don't see why User:Ben Tillman had to bring something irrelevant into this discussion.
I have to keep my promise, but the image I put up is representative of geometry (differential geometry in fact and also has very important applications in fibre bundle theory), small and clear, easy to understand, and probably the same as the previous image except for the fact that they represent different topics. What is the problem (you don't have to answer this and if no-one does I might as well revert my inclusion of that image)?
Topology Expert ( talk) 12:48, 20 November 2008 (UTC)
By the way, there was an edit conflict and I just wanted to note that the connected sum belongs to differential geometry.
Topology Expert ( talk) 12:48, 20 November 2008 (UTC)
Please note also that many of the articles in {{ geometry-stub}} are about things Euclid would recognize as geometry, which may be very different from the things a modern mathematics department's hiring committee would recognize as geometry. — David Eppstein ( talk) 15:32, 20 November 2008 (UTC)
You may as well revert then. I thought it was quite visible but that's my opinion. Anyway, Euclid was 2000 years ago, as far as I know no-one works in Euclidean geometry any longer.
But now that I look at it, maybe I will vote 0 as well.
Topology Expert ( talk) 23:44, 20 November 2008 (UTC)
Topology Expert ( talk) 02:13, 21 November 2008 (UTC)
But isn't it better compared to the image of the dodecahedron?
Topology Expert ( talk) 02:19, 21 November 2008 (UTC)
By the way, metric geometry and Euclidean geometry are different fields. What you cited was a result at their intersection. I have not read the proof, but does it use the Euclidean metric?
Topology Expert ( talk) 02:22, 21 November 2008 (UTC)
0 The dodecahedron is good because it is visible (unlike the other proposed image) and immediately conveys "geometry" to even a non-mathematician. siℓℓy rabbit ( talk) 02:28, 21 November 2008 (UTC)
I have indeed made mistakes in the past, but so have quite a few people in this discussion (I can't think of anyone who has not made mistakes; take Cauchy for instance. He thought that every separately continuous function was continuous and yet he is such a famous mathematician). I also think that many people would make the occasional mistake, at least, if they did not have access to much (if any) 'mathematics information'.
I learn mathematics by thinking (by working out results on my own and just reading the bare minimum of the definitions). Therefore, I make mistakes sometimes and of course, I may have some misconceptions. Even now, I make mistakes (now and then) but hopefully this should not be seen as vandalizing. I can also safely say that the field I know best is topology (but I know other fields reasonably well too) (believe it or not, I can prove many topology theorems on my own (including published ones such as Urysohn's lemma (no hints whatsoever)). I don't mean to boast, but I am just defending myself from people who think they are 'better' because they have higher qualifications. By 'topology expert' I do not claim to be better than everyone anyway. Even though you may not know my real name either, if you did, you would get quite a few (respected) results on the internet if you searched it up; plus I have been on television (thought this is irrelevant, at least it illustrates that I have some credentials). Since you already suspect it, I might as well admit that I am nowhere near a first year student but that does not say that I may not know graduate maths. I also hope that I am not judged because of this; if so, Wikipedia is discriminatory. Users such as User:Hans Adler and User:David Eppstein may be famous but that should not mean that they can attack annonymous users. I appreciate that some users don't consider themselves better because of their credentials ( User:Plclark, Silly rabbit and many other such editors in this discussion for instance) and even silly rabbit: he does not give his real name but I certainly do not doubt that he knows maths very well.
One more point. Apart from a textbook on topology, I don't have many mathematics resources. Therefore, to learn maths, I am inclined to learn the necessary definitions from Wikipedia (then I can think about these definitions for years!). This has led me to start editing Wikipedia. Every single person has the right to learn mathematics. I mean, I can buy textbooks if necessary, but why not take advantage of a free encyclopedia such as this one. If I thought I was so clever, I would not spend time editing Wikipedia and furthermore, I always defend Wikipedia (you'd be amazed at the number of people who think Wikipedia is rubbish). In fact editing Wikipedia also helps me to learn; I read an article on a concept (say if I was learning what a topology was) and I change any incorrect statements based on the definition. This is a really efficient way of learning and furthermore, Wikipedia has imbedded in it the opinions of many mathematicians which is very good. This also explains why I am not a fan of references; most of the things I add to Wikipedia are from my head (even theorems and results but after hearing about WP:OR, I stopped this).
Think whatever you like of me but just because I maybe younger than you (and high-school students) does not mean that I cannot have the same credentials (you can't say that it is impossible for a 13-year old to publish something let alone a first year student). In fact, I have almost done so.
Topology Expert ( talk) 13:08, 21 November 2008 (UTC)
Well, I don't really want people to think me any differently knowing that I am younger than a high-school student. I just wanted to illustrate that someone can know maths even without having a PhD. I guess sooner or later people would have found out (not being a fan of references is an indicator).
I guess we should forget about the algebra stub template discussion (and I will leave them alone) so we can get back to normal editing. I suggested a circle though... (revert if you think it is not good (no need for voting)). I am currently looking to improve locally connected space and fibre bundle (an article especially in the need on attention). Perhaps knowledgeable users can contribute?
I can go by the fact that I shouldn't meddle in number theory for instance because I don't know anything about it. That's what I meant when I argued about qualifications and knowledge.
Topology Expert ( talk) 14:14, 21 November 2008 (UTC)
Oh, and just something that might interest you ( User:Dmcq is that the second edition of Counterexamples in topology costs less than $10 so you might as well buy a copy.
Topology Expert ( talk) 00:59, 22 November 2008 (UTC)
P.S Just to note there is a at least one field medalist who contributes to Wikipedia.
Does that make it better? Is the one you know a mathematician (if you look at the Wikipedia:Wikipedians with articles page, one is listed)? As I know Oded Schramm also could have probably won a fields medal (if he was younger) but that's just for interest.
Topology Expert ( talk) 03:59, 22 November 2008 (UTC)
Topology Expert ( talk) 01:04, 23 November 2008 (UTC)
On the note of content, I do hate people tracking down my edits (most of the time not finding any mistakes but then exaggerating one mistake in a few months to at least some being problematic). But they will soon get tired of it when no mistakes come up.
Topology Expert ( talk) 01:04, 23 November 2008 (UTC)
I am not sure if this discussion is still active, but I think that the current geometry stub template picture, Template:Geometry-stub is perfectly fine and is much better than the connected sum picture. The connected sum is fundamentally a topological rather than a geometric concept so it is not really appropriate for a geometry stub template. Connected sum might be a topology template candidate, but again I think that the current picture of the Klein bottle used in Template:Topology-stub is perfectly fine and does not need to be replaced. Nsk92 ( talk) 01:19, 23 November 2008 (UTC)
My reply to User:Nsk92: The connected sum has several applications in the theory of fibre bundles. OK, perhaps the definition of the connected sum is topological. But what is the purpose of the connected sum? The connected sum is 'geometrical' because it has a lot of applications in differential geometry.
Topology Expert ( talk) 03:13, 23 November 2008 (UTC)
Distances and angles, only??? Manifolds are used mostly for geometry. I am not saying manifolds have nothing to do with topology (they are of course important in this field) but which topic are they most used in (Riemannian geometry as you mentioned is a subfield of geometry)?
Topology Expert ( talk) 07:24, 23 November 2008 (UTC)
The article, geometry is getting vandalized (more than twice every day) by idiots who have nothing better to do than vandalize. Can't we do something about it? For at least the whole time the article existed, most edits are either:
a) Vandalizm
b) Reverting vandalizm
Something has to be done. I would suggest:
a) Semi-protect the article (more important)
b) Block vandalizers for a day for any vandalizm; increase this block to a week, then a month etc.. until an indefinite block if abuse is repeated. I think that vandalizers are dealt with too lightly on Wikipedia.
But since I am not an admin, I would leave the decisions to a real one.
Topology Expert ( talk) 07:33, 23 November 2008 (UTC)
A single-purpose account User:Boolean hexadecimal, proposes replacing a large amount of text in tables with a large imagemap (so that the text is replace by an image of text). The image is not only less clear than the tables, it's awful for accessibility. Could someone else look into this? — Carl ( CBM · talk) 20:56, 18 November 2008 (UTC)
Hi,
what I like about the representation above is the following:
Concerning accessibility:
It is true, that articles should also be accessible to blind people, and for plain text uses, may it be for wapedia or whatever. I take that very serious. But in these cases a table containing wikipedia math symbols would be not useful as well. Thus a good solution for all kinds of users is to keep the imagemap template in the article, and to add a note like this: " Here you find this information in plain text."
The lines in this table should simply look like this:
The information displayed in the Hasse diagram can be shown by a simple list of conclusions like these:
I can create this subpage Logical connectives text table, if you agree that it makes sense. I think it does.
Greetings, Boolean hexadecimal ( talk) 12:19, 26 November 2008 (UTC)
As many people here are probably aware, there is apparently a bug causing LaTeX formulas to no longer appear. It seems like texvc refuses to regenerate pngs, like it doesn't know that the previously cached images are no longer available. This has happened before, but it was always fixed within hours of the problem appearing. The problem now has been ongoing for several days. Does anyone here know if the devs are aware of this problem? If so, is some effort being made to fix the problem? How long should we expect this to continue? siℓℓy rabbit ( talk) 13:55, 23 November 2008 (UTC)
I'm finding yet another instance in golden ratio just below the words "Number of the Beast". Two lines of unrendered TeX code. Purging hasn't helped. Michael Hardy ( talk) 20:08, 24 November 2008 (UTC)
I don't believe purging helps. Last time I checked, was not working either. — Carl ( CBM · talk) 00:25, 25 November 2008 (UTC)
Thank you, Brion. Michael Hardy ( talk) 03:27, 26 November 2008 (UTC)
Looking at the assessment and categorisation of mathematics articles it seems to me that many improvements can be made and this WikiProject can be brought more into line with other projects. There could be several advantages to this.
My main proposal is that we convert the project banner {{ maths rating}} to use the standard meta-banner Template:WPBannerMeta. I have done quite a bit of work on this and the result is currently at Template:WikiProject Mathematics. It does not look exactly the same as the current one - I've got some examples to show you below. Other proposals are:
Please see my sandbox for various different combinations. In order to show comments it was necessary to use mainspace, so I've pasted the proposed new banner on the following pages to demonstrate:
I will take personal responsibility to ensure that any changes work as desired and any teething problems are fixed. Your thoughts please? MSGJ 20:48, 17 November 2008 (UTC)
Well that's one thing that seems to be decided then (stick with Priority over Importance). Does anyone have any answers to my three questions? MSGJ 07:03, 19 November 2008 (UTC)
The new template does not "categorize" Bplus articles as B articles – it completely replaces the Bplus class with B class. So there would be no more Bplus articles at all. In the past there has been support for keeping the Bplus rating. What do people thing now? — Carl ( CBM · talk) 14:18, 20 November 2008 (UTC)
Keep B+. It serves a useful purpose. linas ( talk) 04:27, 4 December 2008 (UTC)
Our longstanding consensus has been that the maths rating template is for rating math articles, not for tagging every page that is somehow related to math. Since the new banner template is quite willing to allow people to tag templates, categories, etc. with it, that's a problem. We could add a check to the template so that it only works on Talk: pages and not on other pages. It's really a pain to have to go back through and fix these after they have been mistakenly tagged by a well-intentioned editor (I know from experience). — Carl ( CBM · talk) 14:20, 20 November 2008 (UTC)
Regarding proposal 5 above, it seemed to me that these categories had too much information on them and were very cluttered. You needed to scroll down a long way to actually see what articles were in those categories. My proposal is to have some brief information about assessing articles and a link to a page with the full details. The more standard method is just a simple template at the top which links to the other categories (see this [[:Category:B-Class Berbers articles|example). I know a lot of work went into the WikiProject_Mathematics/Wikipedia_1.0/Assessment_category_format template and I don't intend to disparage it. But I'm wondering about the rationale of having on every single category page. MSGJ 15:10, 20 November 2008 (UTC)
The new template doesn't seem to do anything with the "field" parameter. Is this a bug? -- Trovatore ( talk) 22:11, 20 November 2008 (UTC)
We have a non-empty set of Category:C-Class mathematics articles. This category does not seem to be well integrated with the rest of the WP-math system. What should be done with this category? -- Salix ( talk): 11:19, 24 November 2008 (UTC)
259 articles link to The Wolfram Demonstrations Project, which redirects to Wolfram Demonstrations Project. Could people help bypass the redirect? Michael Hardy ( talk) 12:42, 1 December 2008 (UTC)
Thank you. I'll get to some of them myself later today unless someone beats me to it. Michael Hardy ( talk) 17:30, 1 December 2008 (UTC)
...I've done a dozen or so so far. Michael Hardy ( talk) 21:51, 2 December 2008 (UTC)
Anyone who is interested is welcome to contribute. Any comments/feedback (however minor) will be greatly appreciated.
Thanks, Topology Expert ( talk) 11:12, 20 November 2008 (UTC)
This is more like wish list, but it would be very nice if the article discusses closed-related topics such as Locally simply connected space or Semi-locally simply connected space. Also, the examples section should contain more concrete examples, examples familiar to non-topologists, if any. (I know very little topology, so I can't edit the article myself.) By the way, I really liked the intro; compactness implies locally compactness, but connected doesn't imply locally connected. This is probably basic but conceptually important, I suppose. -- Taku ( talk) 12:14, 27 November 2008 (UTC)
I am back from an unanticipated Wikibreak and I am extremely pleased with the changes made to the article. Thankyou very much to Plclark, geometry guy, Jakob and other editors for contributing. I will follow up on the comments by Jakob and geometry guy that have not yet been attended to. I will also respond more on the article's talk page but it may take until tomorrow. Just a note: after the recent changes, has the article improved to GA class?
The article mentions that an open subset of a locally connected space is locally connected and hence the same holds for Euclidean space. Plclark: your edits were very helpful but I feel that they are missing out on generality. For instance, originally I had written that an open connected subspace of a locally path connected space is path connected and now it is changed to the special case where the subspace in question is the whole space (and just an unrelated note that local path connectedness cannot be changed to local connectedness in the hypothesis of the theorem as a countable set given the cofinite topology shows; maybe this example could be added). I had earlier written that any linear continuum is locally connected and connected and now it is just restricted to R. I prefer generality rather than examples (prove that a weakly locally connected space is locally connected and then there should be no need to prove this for a particular weakly locally connected space). Anyway, this can be fixed (it will take sometime though) but until then, perhaps editors should stick to being general.
Thanks again.
Topology Expert ( talk) 15:25, 4 December 2008 (UTC)
User:JRSpriggs is attempting to sway a deletion process with Personal attack on physics project page. I removed the comment, but he reinserted it. Comment was added here: [4] and removed here: [5] and then reinserted here: [6]. Delaszk ( talk) 11:13, 28 November 2008 (UTC)
The article has now been deleted, but a Deletion review has been opened. Comments welcome. Geometry guy 21:19, 29 November 2008 (UTC)
This is not the only time that User:JRSpriggs has made a (false) personal attack to hide his misunderstanding/incompetence. See this and notice that JRSpriggs undid that edit because of his lack of knowledge (he did not even bother to read that section to see the counterexample mentioned as silly rabbit pointed out).
Topology Expert ( talk) 18:00, 4 December 2008 (UTC)
Thankyou for the apology but this is just my explanation as to why the placing was correct:
Topology and set theory are so closely linked that they are practically the same subject except for the fact that in topology you analyse a collection of sets satisfying certain axioms rather than analysing sets in general. So really, it would be strange for there to be no topology in an article on set theory and anyhow the theorem I included was proving the uncountability of the reals (shouldn't a reader be able to read as many proofs of this fact on Wikipedia as he wants?) (Wikipedia is an encyclopedia, yes, but you can't be so restrictive as to not include anything apart from what the article's subject is) (I certainly find any proof of the uncountability of the reals interesting).
But since the issue is not sorted out there is no need to discuss it again.
Topology Expert ( talk) 08:02, 5 December 2008 (UTC)
Stallings has recently passed away and this news is now spreading through the math community (see for example [7]) I put a current event tag on the article. Others may wish to watchlist the article for a time. -- C S ( talk) 21:46, 1 December 2008 (UTC)
User:WWGB insists on removing the recent death tag. Finally, s/he has given a reason: "not recent death". Does this make sense? Stallings has reportedly died on Nov 24. That would not only seem recent but since he is not a Britney Spears type celebrity, we can expect that the articles and information on his death will take longer to come out than a week or two. -- C S ( talk) 16:37, 5 December 2008 (UTC)
OK, I've finally added Stallings to the list of deaths in November 2008. I didn't do this earlier because I didn't know the precise date of death. In included a link to the Berkeley page announcing his death, and I notice that the Berkeley page includes a link to his Wikipedia article. Michael Hardy ( talk) 17:38, 5 December 2008 (UTC)
I have been working over on WP:DERM for a while, but am looking to work on the Gabriel's_Horn article, as I also have an interest in math. However, I am not as familiar with the WP mathematics policies, and wanted to know if someone could point me in the right direction. For example, I would like to expand the derivation of Gabriel's_Horn so that there are "smaller" steps. Would this be ok to do. Also, I do not notice any sources on that page. May I cite a mathemathics book within the dervation, or does math speak for itself? Thank you all for your help in advance! kilbad ( talk) 17:09, 2 December 2008 (UTC)
Any criticism about the Mayer–Vietoris sequence article would be appreciated. GeometryGirl ( talk) 17:47, 5 December 2008 (UTC)
And on that note there are a few suggestions at Talk:Vector space as to how the article can be improved. Improvements are welcome.
Topology Expert ( talk) 17:07, 7 December 2008 (UTC)
I know this is a kind of tall order, but i thought if i mention it, some people would possibly keep this in mind. There are some people, such as me, who don't really understand Algebra, but have an intuitive understanding of geometry. This means that if you explain something to me using algebraic notation, i won't understand a thing, but if you plot it on a piece of paper, I will most likely get it. I know I'm not the only one like that. Would it be possible, in the creation of new articles and the overhaul of older ones, to try to - in addition to the legions of formulas - give a geometric representation as well? Thank you very much for your time and effort, and for making wikipedia a more comprehensive resource - hopefully for everybody.-- ExpImp talk con 00:27, 3 December 2008 (UTC)
Having an intuitie understanding of geometry is very important to be able to do it (to do any math subject, you have to understand it intuitively; you can't just expect to write down the correct result from the top of your head). An image can help to illustrate a concept but an image is never a replacement for the formal definition.
Topology Expert ( talk) 18:06, 4 December 2008 (UTC)
The following points apply:
a) The _ looks ugly, yes. Therefore, we have LaTeX.
b) Commutative diagrams are images and I would accept that as a formal definition. But my point is that you cannot replace a formal definition with an image; not that you cannot add an image as an accompaniment to a formal definition.
Topology Expert ( talk) 08:07, 5 December 2008 (UTC)
Sometimes even when the semantics are ad hoc and informal, an image can be a much easier and still perfectly rigorous way of describing a mathematical object. Example: there exist 20 points in a 10x10 grid such that no three of the points are collinear. One can easily give a picture (right), which should be completely convincing. But describing those points in text (e.g. by giving their coordinates) would be tedious and error-prone. In fact, if I were given a list of 20 text coordinates and asked to verify whether they had this property, I think the easiest way to do so would be to draw the picture; I'd much rather do that than hand-enumerate all 2280 triples of points and go through a 3x3 determinant calculation for each triple to verify symbolically that they are non-collinear. — David Eppstein ( talk) 16:19, 5 December 2008 (UTC)
Yes proofs can use pictures (like many category theoretical arguments (I would classify a commutative diagram as a picture) or even the proof of the homotopy lifting lemma). In fact, I think that most people would prefer to prove simple facts like that the nth homotopy group of a space is actually a group by using pictures rather than giving a complex formulae for homotopies. Topology Expert ( talk) 15:52, 9 December 2008 (UTC)
Topology Expert ( talk) 20:42, 7 December 2008 (UTC)
You don't get it do you (for a start, the image constitutes a proof; not a formal definition)? Topology Expert ( talk) 15:52, 9 December 2008 (UTC)
Hello experts, some time last year there was some hullabaloo about repeated recreation, apparently by COI socks, of an article about so-called Boubaker polynomials. The consensus turned out to be there were no reliable independent sources establishing notability, and I closed the latest Afd ( Wikipedia:Articles for deletion/Boubaker polynomials (2nd nomination)) as "delete with prejudice against re-creation". Now, there is again a new editor, Luoguozhang ( talk · contribs), who has recreated Boubaker polynomials and a second, related article at BPES (guess what the "BP" stands for).
It does seem to me that he is now citing some independent sources, but I have no idea about the topic area and can't judge reliability. Can people with more topic knowledge please go and check if those articles are legit? Fut.Perf. ☼ 18:42, 6 December 2008 (UTC)
I've redirected it and deleted the links to it from the main article. Michael Hardy ( talk) 14:49, 7 December 2008 (UTC)
How can someone create so many sockpuppets?
Topology Expert ( talk) 15:57, 9 December 2008 (UTC)
I started editing the article dependent and independent variables, which was a real mess, and added some cited content under the math section. However, there is all this content under the statistics section that is uncited, and wanted to know if someone would help me find sources for this information, or challenge and remove it? kilbad ( talk) 03:12, 9 December 2008 (UTC)
We have dozens of links to the "Earliest Known Uses of Some of the Words of Mathematics" site, but this site has moved and the old links are now broken. The old URLs are of the form http://members.aol.com/jeff570/e.html and the new ones are of the form http://jeff560.tripod.com/e.html . Anyone who feels like updating some of these links can find them using the LinkSearch page. -- Zundark ( talk) 09:34, 9 December 2008 (UTC)
If anyone has some time, could they have a look at the Branch point article? It only gives an informal description before listing some examples, and finally mentions its usefulness and development in Riemann surface theory in the last couple of sentences, but again doesn't really give anything very concretely. I had a look at a few complex analysis books I had handy, and, well they tended to keep it pretty informal too, so I don't feel too confident having a crack at this myself. Cheers, Ben ( talk) 12:12, 10 December 2008 (UTC)
The concept is pretty basic in complex analysis (and in algebraic geometry) so I think you should have a go at editing it. After all, you should have a go. If at all you make a mistake, someone can easily correct it. I will add some examples to that page (and a proper formal definition for a start) and note that the branch point is defined only for holomorphic functions. Basically, a branch point of a holomorpic function (defined of course on the complex plane), is simply a point which gets mapped onto different values depending on its complex argument. Basically, a point z in the complex plane has countably many arguments (if its argument is θ, then its argument is also θ+2πn for all n in Z) and if the function value of z depends on the argument you choose, then z is called a branch point. The most obvious example of a function whose every point is a branch point is the function mapping a complex number to its argument. An example of a function with no branch point is the function mapping a point to its modulus. Think about this and have a go at editing the article. If I get time I will add a few facts myself.
Topology Expert ( talk) 13:46, 10 December 2008 (UTC)
Nope, they aren't. But I don't see why 'holomorphic' has to be included in the definition (as long as the functions are continuous and you can 'speak of' the change of a function along any path in the complex plane, that should be enough. And surely f is differentiable on any path in the complex plane?).
Topology Expert ( talk) 14:18, 10 December 2008 (UTC)
I added an equivalent (from the top of my head) definition to the article on branch point of a branch point of a function using the notion of a winding number. Anyone care to have a look at it (the second definition)? In my opinion the one I added from the top of my head is probably more mathematically formal.
Topology Expert ( talk) 14:20, 10 December 2008 (UTC)
The article (in the section on Riemann surfaces) writes the following:
The concept of a branch point is defined for a holomorphic function ƒ:X → Y from a compact Riemann surface X to a compact Riemann surface Y (usually the Riemann sphere). The function ƒ, unless it is constant, will be a covering map almost everywhere
This is meaningless in the sense that what does 'almost everywhere' mean. It can't be in the context of measure theory because there is no natural way (i.e to make a Riemann surface into a measure space such that the two structures are compatible) to make a Riemann surface into a measure space (forgive me if there is; I am not an expert on the subject). So what does it mean? Perhaps it (most likely) means that the map f is a covering map for all but a finite number of points but if so, this should be explicitly mentioned (and made more precise). Any opinions?
Topology Expert ( talk) 14:43, 10 December 2008 (UTC)
It also depends on what you consider a ‘covering map’ (i.e, whether you require a covering map to be surjective or not). But since the ‘result’ specifically excludes the constant map, it is probably not surjectivity (the constant map will yield a non-discrete fibre and hence cannot be a covering map).
Topology Expert ( talk) 14:55, 10 December 2008 (UTC)
I will copy this section there but let us continue it here because there are currently disputes regarding the material in that article (and hence we want as many mathematicians as possible to give their opinions). No one is going to go to the talk page of that article within a 100 years anyhow!
Topology Expert
OK
Topology Expert ( talk) 17:17, 10 December 2008 (UTC)
Is anyone else getting errors like this
on perfectly good LaTeX code every now and again? Is this something that the devs should be bothered with? siℓℓy rabbit ( talk) 22:24, 7 December 2008 (UTC)
The same thing just happened to me. Paul August ☎ 03:55, 9 December 2008 (UTC)
The "completeness relation" section in Hermite polynomials is not clearly written. Obviously whoever put it there was verbally challenged. I can't tell what it says. Not that I've exerted great effort on the point, but the meaning should be clear without that. Can someone help? Michael Hardy ( talk) 18:08, 11 December 2008 (UTC)
I may not have exactly got what is necessary (someone will have to fix up the LaTeX) but I basically only cleaned up the verbal bit (perhaps 'logically challenged' would be less insulting and more appropriate). Topology Expert ( talk) 20:27, 11 December 2008 (UTC)
Silly rabbit fixed up the LaTeX. How does it look now?
Topology Expert ( talk) 20:42, 11 December 2008 (UTC)
Please can any one tell me if these polynomials have any Exponential Generating Function and if their roots have any analytical expression ? (and please where can one find the Exponential Generating Function for Chebyshev Polynomials ?? Duvvuri.kapur ( talk) 22:32, 12 December 2008 (UTC)
New user Wayp123 has been adding a number of links to his/her website [10] and, after my deleting them, wishes to reinsert them. I don't see the notability of the site, but wanted to post here to discuss this in more generality (affected articles include matrix (mathematics) and linear map). Jakob.scholbach ( talk) 06:27, 8 December 2008 (UTC)
"New" user Wayp123 is in a strict sense not "new", since he was previously warned for spamming more than 2 years ago. But perhaps "new" in the sense of only having made intermittent spamming forays into Wikipedia and not really understanding how it functions. -- C S ( talk) 04:24, 9 December 2008 (UTC)
(ec) The principle behind Wikipedia, and the reason for its success, is WP:CONSENSUS. While consensus cannot usually be measured in terms of head counting, it seems quite easy in the case of this discussion. For inclusion: Wayp123 (1 editor, note WP:COI). Against inclusion: Jakob.scholbach, Paul August, RobHar, Hans Adler, C S, Salix alba, Silly rabbit, Msgj (8 editors). Please stop beating this dead horse. -- Hans Adler ( talk) 13:28, 9 December 2008 (UTC)
I think you are all paid wiki staff so I have no say. Wayp123 ( talk) 13:39, 9 December 2008 (UTC)
Neither do I. I just like to contribute for fun. Topology Expert ( talk) 17:05, 9 December 2008 (UTC)
Goodbye for now, Ill be back! Wayp123 ( talk) 13:50, 9 December 2008 (UTC)
That's an interesting point: On the survey, there was a question asking whether you are paid for editing Wikipedia (i.e Question: What is your reason for editing Wikipedia? and Choice: Because I am paid to do it). Maybe people are paid...
Topology Expert ( talk) 14:08, 9 December 2008 (UTC)
By the way, aren't C S and silly rabbit supposed to be on a wikibreak? (I couldn't resist myself either! I wonder whether anyone who put a wikibreak tag on his page has actually managed to pull it off...).
Topology Expert ( talk) 14:12, 9 December 2008 (UTC)
Oh, I nearly forgot: My daughter lost her gloves at the staff Christmas party last night. If one of you found it, could you please put it on my desk tomorrow? Thanks. -- Hans Adler ( talk) 17:50, 9 December 2008 (UTC)
Have you gone mad? (or is it just that I don't get the joke here?)
Topology Expert ( talk) 17:59, 9 December 2008 (UTC)
Current score: 9 paid Wikipedia staff members — 1 independent contributor who is only interested in improving the encyclopedia. -- Hans Adler ( talk) 21:44, 9 December 2008 (UTC)
To tell you the truth, I'd rather not hear about this party anyway.
Topology Expert (
talk) 11:00, 10 December 2008 (UTC) How do you know that I was not there?
Topology Expert (
talk)
20:05, 10 December 2008 (UTC)
I noticed that the day after the party, a team of plumbers were called to the venue. I am still baffled about this but I think it had something to do with the fact that David Eppstein was in the toilets for more than an hour. Topology Expert ( talk) 22:43, 12 December 2008 (UTC)
Please can any one tell me if the Boubaker polynomials have any Exponential Generating Function and if their roots have any analytical expression ? (and please where can one find the Exponential Generating Function for Chebyshev Polynomials ?? Duvvuri.kapur ( talk) 22:34, 12 December 2008 (UTC)
Please ask this at the reference desk. Topology Expert ( talk) 22:44, 12 December 2008 (UTC)
Thanks, we did not know the existence of this page..
Duvvuri.kapur (
talk)
23:39, 12 December 2008 (UTC)
The article on group actions contains a bit about orbit spaces (namely when a topological group acts on a topological space, one can consider the collection of all orbits as a quotient space) but such an important concept (namely the theory of Lie groups/topological groups acting on topological spaces) deserves its own article (I can explain its importance in mathematics if necessary). One very important application is:
I can create the article but I would appreciate it if some people could help out there (I am sure there are many applications which I would not know about).
Topology Expert ( talk) 15:08, 10 December 2008 (UTC)
Also there should be a proper article on orbit space. What would we call the article (namely the article describing the theory of topological groups/Lie groups acting on topological spaces) if we were to create it?
Topology Expert ( talk) 15:09, 10 December 2008 (UTC)
Yes, I forgot about orbifolds! But they really don't completely discuss the whole theory behind topological groups acting on topological spaces. Topology Expert ( talk) 09:15, 11 December 2008 (UTC)
Isn't anyone else going to comment on whether this idea is good or not? Or at least list some other concepts in this theory that they know? I think that there should be a category on this (just like there is a category:topology). Opinions (I am disppointed at the lack of enthusiasm when a subject related to topology is bought up. I know that there are lots of knowledgeable people on the subject (here) but most don't seem interested enough to comment. I once raised awareness that the article on fibre bundles is under par along with some (in fact a lot of) comments but no-one bothered to do anything until I personally asked some editors on their talk page)? Topology Expert ( talk) 14:17, 13 December 2008 (UTC)
You can get symbols inside a circle with oplus,ominus,otimes but how do you get symbols inside a square ? This is needed for the article gyrovector space. Delaszk ( talk) 16:27, 13 December 2008 (UTC)
A pair of editors have explicitly stated that they are in favor of deleting the article. It is of course their right to nominate the page for deletion. In the meantime, they are involved in edits that tend to degrade the quality of the article, in some cases based on ignorance of NSA. Can a case be made that if their intention is to delete it, they should refrain from further damaging edits so as not to predetermine the outcome of a deletion discussion? Katzmik ( talk) 08:18, 11 December 2008 (UTC)
I initiated a discussion on the talk page of the article (and gave reasons as to why I do not support the merge). Topology Expert ( talk) 21:50, 12 December 2008 (UTC)
Because I am supposed to follow the 'rules', I have copied the voting into the talk page of the article. Voting there is encouraged. Topology Expert ( talk) 22:26, 13 December 2008 (UTC)
(indent) Following the suggestions of numerous editors, the article has now been listed at AfD Wikipedia:Articles for deletion/Bishop–Keisler controversy. Mathsci ( talk) 05:28, 14 December 2008 (UTC)
I want to point out that if you merge this article into non-standard analysis, you should at least keep a redirect (not that I support the merge). Since this is a very famous controversy (as several users have pointed out), someone searching it should be able to go to its article and then be redirected. Deletion is simply ridiculous. Topology Expert ( talk) 11:09, 14 December 2008 (UTC)
I noticed that there seems to be a passive-agressive struggle in the edit comments of the Grothendieck article over whether he is Category:French people of German descent. Since December 7th, User:Feketekave and a few IP addresses (all similar, so probably the same unregistered editor) have been alternately deleting and re-inserting this category into the article, with Feketekave claiming it is "racialist" and the IP claiming that removing it is "vandalism". There have been now three rounds in this altercation, the two most recent being all four of the latest edits. These two need to be brought to heel and the issue should probably be discussed in the open now as well. I note that Grothendieck's ancestry and nationality have already been the subject of some debate, wherein his being Jewish (or not) was concerned. Ryan Reich ( talk) 17:15, 14 December 2008 (UTC)
Someone has been adding way too much to this category, and at the same time inexplicably missing obvious things like Dehn surgery. I wanted to post here for discussion before I start to unilaterally remove articles from the category. siℓℓy rabbit ( talk) 23:20, 5 December 2008 (UTC)
I undid silly rabbit's edit of removing homotopy groups from the Category:Surgery theory because they are used in surgery theory but I don't think they would be called part of surgery theory (an analagous case is the continuum hypothesis which is used in topology but not really part of it). Is this way of adding concepts to a category correct according to the Wiki conventions? I think that homotopy (and homology) groups are very important in surgery theory so because of this importance they should be included in the category but I would like another editor's opinion. Topology Expert ( talk) 17:00, 7 December 2008 (UTC)
Well, surgery theory does answer some questions in homotopy (and homology) theory regarding manifolds so I think they should be included. Topology Expert ( talk) 17:02, 7 December 2008 (UTC)
(unindent) OK, here is a question: should homotopy theory be included in Category:Fibre bundle and vice-versa? Any fibre bundle theorist will agree that the 2 are very closely related. Topology Expert ( talk) 11:26, 8 December 2008 (UTC)
It looks as though User:Ranicki has undone a few of my changes, adding things like Manifold and Lens space back to Category:Surgery theory. To me, this seems like overcategorization, as discussed above. I am going to again remove things from the category which do not belong there. siℓℓy rabbit ( talk) 15:20, 14 December 2008 (UTC)
I have never drawn commutative diagrams on a computer. The article commutative diagram contains pictures but no LaTeX. Could someone help me make the commutative diagram expressing the naturality of the Mayer-Vietoris sequence? Thanks, GeometryGirl ( talk) 20:53, 13 December 2008 (UTC)
I've just cut and pasted the follwoing from one of my LaTeX 2e files. It works perfectly well on there:
Failed to parse (unknown function "\begin{CD}"): {\displaystyle \begin{CD} R^2 \times R^3 @>\pi_1 >>R^3 @> f >> R \\ @V (A,B) VV @V B VV @VV \mbox{id} V \\ U \times S^2 \times I @>\pi_2 >> S^2 \times I @> g >> R \end{CD} } Δεκλαν Δαφισ (talk) 18:17, 18 December 2008 (UTC)
The "new user" User:Point-set topologist has added Wallpaper group to the category of mathematics Featured Articles, despite the fact that it seems not to be a featured article. It seems to me that this is a mistake; could someone more familiar with the GA/FA procedures confirm this? Plclark ( talk) 22:22, 17 December 2008 (UTC)
Are we now using C-class for the rating or not? I got the impression from Wikipedia talk:WikiProject Mathematics/Archive 43#Overhaul of assessment and project banner, at the bottom, that we're not. -- Jitse Niesen ( talk) 23:37, 17 December 2008 (UTC)