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| There are discussions taking place about the article ] and the redirect ]. A Hurwitz algebra is synonymous with a ] on which there is an existing article (except that a few authors do not require composition algebras to be unital). However, it is claimed that ] should not redirect to ] but to the related ] on the grounds that ] is "inadequate" , and "There is no content in the ] article" . Comments of expert editors would be helpful at ] and ]. ] (]) 17:09, 29 April 2013 (UTC) Update: ] has just been moved to ]. ] (]) 18:16, 29 April 2013 (UTC) Further update: anyone looking for the discussions will need to look at both ] (plural) and ] (singular) as something odd seems to have happened to the redirections. ] (]) 19:35, 29 April 2013 (UTC) | There are discussions taking place about the article ] and the redirect ]. A Hurwitz algebra is synonymous with a ] on which there is an existing article (except that a few authors do not require composition algebras to be unital). However, it is claimed that ] should not redirect to ] but to the related ] on the grounds that ] is "inadequate" , and "There is no content in the ] article" . Comments of expert editors would be helpful at ] and ]. ] (]) 17:09, 29 April 2013 (UTC) Update: ] has just been moved to ]. ] (]) 18:16, 29 April 2013 (UTC) Further update: anyone looking for the discussions will need to look at both ] (plural) and ] (singular) as something odd seems to have happened to the redirections. ] (]) 19:35, 29 April 2013 (UTC) | ||
| :As you have noticed, the other editor is a bit prickly, but it is very likely that what they have said is accurate (and he has written a large number of high quality articles). You will get much better results by asking questions and considering the replies. ] (]) 03:22, 30 April 2013 (UTC) | :As you have noticed, the other editor is a bit prickly, but it is very likely that what they have said is accurate (and he has written a large number of high quality articles). You will get much better results by asking questions and considering the replies. ] (]) 03:22, 30 April 2013 (UTC) | ||
| ::I cannot see that this complaint will serve any purpose, except that Deltahedron might discover that I am among the main content contributors to mathematics articles on wikipedia. I don't accept his claims, which contradict what can be found in standard textbooks. My own view, after having seen him "in action", is that he is not very much in touch with this subject and is being pedantic, while showing almost no interest in adding any serious content. So far in his relatively short wikipedia existence, he has created several short stubs. He apparently has no experience with extended content. Even professionally trained mathematicians have to use sources, in-line citations, etc. Misplaced Pages is not a source and cannot invent its own rules for mathematical naming, particularly for interdisciplinary subjects such as this one, which is extensively used in geometry and analysis. On the talk page of the article I mention three sources—Jacobson, Faraut & Koranyi and Springer & Veldkamp. All of these are solid sources. What I have written conforms to those sources. In addition, apart from looking at many other books and articles, I read through the long and fascinating book of Daniel Shapiro, essentially on just this topic. Shapiro gives a very detailed account of the history in the zeroth chapter. What I have written in the article reflects that history quite closely and accurately. In particular in his second posthumous article, which I have read and which was icidentally proofread by ] prior to publiscation, Hurwitz introduces the representation of the real Clifford algebra that appeared in later treatments (e.g. Eckmann, Lee, Chevalley). If I were less busy with ]s, the article that required a detailed account of Euclidean Hurwitz algebras, I would summarise that zeroth chapter in the current article. Much of the material is already there in the main body, but it would do no harm to mention the more general Hurwitz matrix systems and the corresponding problem for composition of forms. I also think that a "further directions" section right at the end could be worthwhile. Shapiro discusses the applications to vector fields on spheres, Bott generators in K-theory, composition of quadratic forms in arbitrary characteristic, generalizations of composition algebras, algebraic K-theory, and so on. A short summary of what can be found in this long and fascinating book would be nice. It also has Conway's treatment of composition algebras (a sort of Archimedeans talk I assume). There are other similar general sources, e.g. the AMS Notices article by Eckmann. Worrying about whether the octonions are a real division algebra or a composition algebra is hardly the point. When ], ] and ] used Hurwitz's work in 1934, it was through the system of Clifford matrices that Hurwitz defined. These mathematical physicists did not use the terminology "Jordan algebras", but the quantum mechanics term "''r''-numbers". I have no idea why Deltahedron has become side-tracked by these minor and trifling MOS-issues. He appears to be making very few substantial content contributions. I have encouraged him to get some experience of writing an extended article so that he has a clearer idea of the relation between the main body of an article and its lede. That would clarify how we rely on sources for writing wikipedia articles, even in mathematics. Bristling, acerbic or whatever you like, those are the rules. A brief look at ] might also be an idea. Thanks, ] (]) 11:29, 30 April 2013 (UTC) | |||
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Misplaced Pages:Misplaced Pages Signpost/WikiProject used
Euclid (Toddhunter)
I note that :- Wikisource:Index:The_Elements_of_Euclid_for_the_Use_of_Schools_and_Colleges_-_1872.djvu is nearing completion in terms of text translation.
It would be appreciated if some WP:MATH people would assist carefully in reviewing it. ShakespeareFan00 (talk) 22:36, 13 April 2013 (UTC)
April disambiguation pages.
Please help fix incoming links to April's most-linked mathematics-related disambiguation pages, Geometric shape, Extra dimensions, Parametric, Positive definiteness, Planar, and Delta function. Some of these may also be questionably ambiguous. Cheers! bd2412 T 03:17, 14 April 2013 (UTC)
- The lack of a proper article at Geometric shape has bugged me for a long time. We have a list of geometric shapes and an article shape which discusses a rather technical statistical usage, but nothing about simple geometric figures.--Salix (talk): 16:37, 14 April 2013 (UTC)
- I made this a stub. Again, a clear non-disambiguation disambiguation page. Please feel free to add. It's currently just a dicdef. Sławomir Biały (talk) 20:26, 14 April 2013 (UTC)
- Isn't a geometric shape just a shape? ᛭ LokiClock (talk) 23:01, 14 April 2013 (UTC)
- Another possibility here would be to redirect geometric shape to list of geometric shapes. —David Eppstein (talk) 23:15, 14 April 2013 (UTC)
- I think that is an excellent suggestion, particularly since the only other close hit, Geometric Shapes, is already on that page. I will see to it. bd2412 T 00:29, 15 April 2013 (UTC)
- On the contrary, if ever there were a clear candidate for a dab entry in this business, it would be shape. Most of the content now at shape would be more appropriate at geometric shape. (And no, the article Geometric Shapes is actually about a Unicode character set, more or less irrelevant as an article to this discussion.) Sławomir Biały (talk) 00:35, 15 April 2013 (UTC)
- This discussion is not about the word "shape", which could well be ambiguous to terms like Body shape, and even Physical fitness (which is also referred to as being "in shape"). It is, rather, about the phrase "Geometric shape", although it now seems to me that we can just move Shape to Geometric shape for both purposes. bd2412 T 00:51, 15 April 2013 (UTC)
- No, it's certainly not about the word "shape. But the article shape is clearly relevant, especially considering that it's a proper article whereas geometric shape is only a dab. My very point is that, if anything, the situation should be reversed: shape should be a dab, with geometric shape containing most of the contents thereof. Do we disagree? I am confused. Sławomir Biały (talk) 01:05, 15 April 2013 (UTC)
- I think we are in agreement, actually. I suggested moving shape to geometric shape, since the current content at shape is all about the geometric variety. The question remains whether shape would then redirect to geometric shape, or whether the shape (disambiguation) would be moved to shape. I don't know that anything on the disambiguation page which would outstrip the geometric meaning, so I think that the latter move would require a requested move discussion. bd2412 T 01:34, 15 April 2013 (UTC)
- No, it's certainly not about the word "shape. But the article shape is clearly relevant, especially considering that it's a proper article whereas geometric shape is only a dab. My very point is that, if anything, the situation should be reversed: shape should be a dab, with geometric shape containing most of the contents thereof. Do we disagree? I am confused. Sławomir Biały (talk) 01:05, 15 April 2013 (UTC)
- This discussion is not about the word "shape", which could well be ambiguous to terms like Body shape, and even Physical fitness (which is also referred to as being "in shape"). It is, rather, about the phrase "Geometric shape", although it now seems to me that we can just move Shape to Geometric shape for both purposes. bd2412 T 00:51, 15 April 2013 (UTC)
- On the contrary, if ever there were a clear candidate for a dab entry in this business, it would be shape. Most of the content now at shape would be more appropriate at geometric shape. (And no, the article Geometric Shapes is actually about a Unicode character set, more or less irrelevant as an article to this discussion.) Sławomir Biały (talk) 00:35, 15 April 2013 (UTC)
- I think that is an excellent suggestion, particularly since the only other close hit, Geometric Shapes, is already on that page. I will see to it. bd2412 T 00:29, 15 April 2013 (UTC)
- Another possibility here would be to redirect geometric shape to list of geometric shapes. —David Eppstein (talk) 23:15, 14 April 2013 (UTC)
Delta function
- Kronecker delta is called delta function by anyone in last 80 years, really? Incnis Mrsi (talk) 18:48, 14 April 2013 (UTC)
- Try Google for "Kronecker delta function". It appears to be standard usage in MATLAB. Deltahedron (talk) 19:12, 14 April 2013 (UTC)
- I think probably the issue is not whether the phrase "Kronecker delta function" has been used recently, but rather whether the exact phrase "delta function" has actually been used to refer to the Kronecker delta. It's hopefully clear that the Dirac delta function is by far the more common use of "delta function" (with no additional qualifications) so I think a disambiguation page (as opposed to a hatnote) is not terribly helpful here. Sławomir Biały (talk) 20:03, 14 April 2013 (UTC)
- Since there are only two articles for "delta function", and the Dirac one is arguably primary, I converted it to a redirect with a hatnote rather than having a separate dab. —David Eppstein (talk) 20:34, 14 April 2013 (UTC)
- I forgot to note here that I disambiguated all the delta function links in article space except the redirects. Thanks for finishing it off. Most of the ambiguous links were in fact referring to Dirac delta functions. --Mark viking (talk) 21:03, 14 April 2013 (UTC)
- And now Delta function is back to being a dab, or will be after the history rearrangement is complete. Are the modular discriminant and Ramanujan delta functions considered the same thing? They're almost the same but the discriminant has a factor of (2π) that doesn't seem to be present when talking about the corresponding cusp form. This is far from my area, though, so maybe I'm just confused. —David Eppstein (talk) 06:53, 16 April 2013 (UTC)
- Could someone please explain what is going on with all the page moves here -- two lots today? Deltahedron (talk) 17:28, 16 April 2013 (UTC)
- There appears to be some disagreement over whether delta function should go to Dirac delta function or to delta function (disambiguation). But if it goes to the disambiguation page, it should be the main title of the page rather than redirecting to it. The page moves are trying to keep the edit history synchronized with the titles. —David Eppstein (talk) 17:38, 16 April 2013 (UTC)
- I'm concerned that all these moves, counter-moves, deletions, undeletions and so forth, are taking place before any kind of consensus has been achieved. Deltahedron (talk) 18:14, 16 April 2013 (UTC)
- And now it's been moved again — Steel1943 seems to be doubting that Dirac should be primary. See Misplaced Pages:Requested moves/Technical requests. —David Eppstein (talk) 23:24, 16 April 2013 (UTC)
- I'm concerned that all these moves, counter-moves, deletions, undeletions and so forth, are taking place before any kind of consensus has been achieved. Deltahedron (talk) 18:14, 16 April 2013 (UTC)
- There appears to be some disagreement over whether delta function should go to Dirac delta function or to delta function (disambiguation). But if it goes to the disambiguation page, it should be the main title of the page rather than redirecting to it. The page moves are trying to keep the edit history synchronized with the titles. —David Eppstein (talk) 17:38, 16 April 2013 (UTC)
- Could someone please explain what is going on with all the page moves here -- two lots today? Deltahedron (talk) 17:28, 16 April 2013 (UTC)
- And now Delta function is back to being a dab, or will be after the history rearrangement is complete. Are the modular discriminant and Ramanujan delta functions considered the same thing? They're almost the same but the discriminant has a factor of (2π) that doesn't seem to be present when talking about the corresponding cusp form. This is far from my area, though, so maybe I'm just confused. —David Eppstein (talk) 06:53, 16 April 2013 (UTC)
- I forgot to note here that I disambiguated all the delta function links in article space except the redirects. Thanks for finishing it off. Most of the ambiguous links were in fact referring to Dirac delta functions. --Mark viking (talk) 21:03, 14 April 2013 (UTC)
- Since there are only two articles for "delta function", and the Dirac one is arguably primary, I converted it to a redirect with a hatnote rather than having a separate dab. —David Eppstein (talk) 20:34, 14 April 2013 (UTC)
- I think probably the issue is not whether the phrase "Kronecker delta function" has been used recently, but rather whether the exact phrase "delta function" has actually been used to refer to the Kronecker delta. It's hopefully clear that the Dirac delta function is by far the more common use of "delta function" (with no additional qualifications) so I think a disambiguation page (as opposed to a hatnote) is not terribly helpful here. Sławomir Biały (talk) 20:03, 14 April 2013 (UTC)
- Try Google for "Kronecker delta function". It appears to be standard usage in MATLAB. Deltahedron (talk) 19:12, 14 April 2013 (UTC)
Yes, yes. Let's just drop it for now. Anyone can comment on the appropriate discussion pages about the ultimate outcome. An RfC might be appropriate, with this project notified along with all affected discussion pages, although at present it seems likely that this can be handled amicably without appealing to a wider consensus. Sławomir Biały (talk) 00:24, 17 April 2013 (UTC)
- This should be resolved just like any other primary topic discussion. Generally, a primary topic is determined by page views and extrinsic evidence of the proportion of real-world uses (on Google and the like) wherein the term is used to refer to proposed primary topic as opposed to other topics. bd2412 T 00:29, 17 April 2013 (UTC)
- If the problem is considered to be settled by Googliomancy, then David Eppstein's solution is obviously the correct one. I challenge anyone to a Google competition on this point. Sławomir Biały (talk) 00:36, 17 April 2013 (UTC)
- I agree completely. A quick Google search yields 320,000 results for Dirac AND "Delta function", compared to 78,800 results for Kronecker AND "Delta function"; Google Books results yield 109,000 results for Dirac AND "Delta function", compared to 20,100 results for Kronecker AND "Delta function". In terms of Misplaced Pages primacy, last month Dirac delta function got 26741 hits, compared to Kronecker delta getting 6870 hits, and (just for the heck of it) Modular discriminant getting 115 hits. bd2412 T 00:43, 17 April 2013 (UTC)
- To me, Mark viking's anecdotal evidence that most of the ambiguous links that he fixed were to the Dirac delta is more convincing, since what we want to know is not how popular the different deltas are but rather how often each is the intended meaning for the unqualified phrase "delta function". But the distinction doesn't matter much, since all the evidence points the same way. —David Eppstein (talk) 01:00, 17 April 2013 (UTC)
- I agree completely. A quick Google search yields 320,000 results for Dirac AND "Delta function", compared to 78,800 results for Kronecker AND "Delta function"; Google Books results yield 109,000 results for Dirac AND "Delta function", compared to 20,100 results for Kronecker AND "Delta function". In terms of Misplaced Pages primacy, last month Dirac delta function got 26741 hits, compared to Kronecker delta getting 6870 hits, and (just for the heck of it) Modular discriminant getting 115 hits. bd2412 T 00:43, 17 April 2013 (UTC)
- If the problem is considered to be settled by Googliomancy, then David Eppstein's solution is obviously the correct one. I challenge anyone to a Google competition on this point. Sławomir Biały (talk) 00:36, 17 April 2013 (UTC)
Positive definiteness
- Positive definiteness should me a multiple cross index page rather than a dab. I know that concept is supposedly deprecated, but you should seriously wonder why it is that every few months it comes to the top of your blacklist. I have gone ahead and changed it to a multiple-cross-reference page. Presumably the onus is now on those who oppose this idea to write an article instead, since it was clearly not a dab page. Perhaps User:BD2412 would obligingly write such an article? Sławomir Biały (talk) 20:20, 14 April 2013 (UTC)
- I would not presume the expertise to begin such an enterprise (which is, of course, why I have come here to seek the help of experts in the field). Cheers! bd2412 T 00:33, 15 April 2013 (UTC)
- Very well, and good luck with that. Unfortunately, no one to my knowledge has so far been willing to write an article on "positive definiteness" in general, despite half a decade of prodding. Although most of us know what positive-definiteness means (precisely in some cases, roughly in others), there is apparently no adequate secondary source that links the various cases. So therefore under our WP:PILLARS, no proper article can be written. Yet equally clearly, this should not be a dab page: the uses of the term are each a hair's breadth from each other. I honestly don't know what this means procedurally, but my suggestion is either: (1) leave it as an unsanctioned {{Multiple-cross-reference page}}, or (2) nominate the page for deletion via the standard process. If neither of these options is tasteful to you, then I should remind you that there is no deadline. Eventually the ultimate expert on positive definiteness in mathematics may come along and write an article that adheres to our WP:PILLARS. Until that time, if you notify this Wikiproject (as you have several times in the past about this very issue) you'll have to be satisfied with the responses offered by the idiotic schlubs that occupy it. Sławomir Biały (talk) 01:27, 15 April 2013 (UTC)
- Of course, if there is no real meaning to "positive definiteness", it raises the question, why do so many articles link to it? As a disambiguator, I only bring here the disambiguation pages that regularly come up as having the most incoming links requiring repair, in the course of dealing with recurring errors. If the concept is ambiguous, the incoming links need to be fixed. If it is unambiguous, then the appropriate page should be there. If some other solution is appropriate, I will be glad to see it implemented. We are all working together here to correct mistakes such as ambiguous links. bd2412 T 02:05, 15 April 2013 (UTC)
- They link to it because they are more interested in the general concept than in specific variations of it. But the rules prevent us from having things that look like disambiguation pages but are allowed to have links. Perhaps that indicates a problem with the rules. Perhaps calling it list of positive definite topics would help; after all, the dsiambiguation rules enthusiasts haven't yet succeeded in ruling that lists are too similar to disambiguation pages to be allowed to exist. —David Eppstein (talk) 02:23, 15 April 2013 (UTC)
- An article on a list of positive definite topics sounds like a good idea. There exist surveys of what positive definiteness means in different mathematical contexts that could be used to provide the intro needed for such an article, for example, Positive definite functions and generalizations, an historical survey and Positive Definite Kernels: Past, Present and Future. --Mark viking (talk) 02:38, 15 April 2013 (UTC)
- I know of no effort on the part of disambiguators to rule that lists are too similar to disambiguation pages to be allowed to exist. In fact, quite the opposite, we have converted many pages into lists that were incorrectly tagged as disambiguation pages, but did not contain ambiguous topics. We have also set up {{SIA}} pages for lists of things that share a common name, but for which examples are unlikely to individually notable (for example, Iasus) or for which references are likely to be for the entire class of members rather than any individual member (like NO2). bd2412 T 02:49, 15 April 2013 (UTC)
- The context is Misplaced Pages talk:Policies and guidelines/Archive 13#Accepting "WP:Multiple-cross-reference page" as a guideline. —David Eppstein (talk) 02:58, 15 April 2013 (UTC)
- I agree with Einstein's proposition: "Everything should be as simple as it can be, but not simpler". I would say that to the greatest extent possible, we should have articles if an article can be written on a topic, no matter how abstract or nebulous the topic; or, if there is not enough material to justify an article, then a section in whatever article encompasses the topic. However, I am all for innovative solutions, so long as we do not end up having disambiguation pages for topics that are not truly ambiguous to one another. In that vein of thought, what should be done with Extra dimensions, which has been tagged as WP:DABCONCEPT? bd2412 T 13:02, 15 April 2013 (UTC)
- IMO, Extra dimensions must be merged as a new section in Dimension (mathematics and physics). For Positive definiteness, I suggest to add at the beginning ot the article the sentence: "Positive definiteness is a property of any mathematical object to which a bilinear form or a sesquilinear form may be naturally associated, which is positive definite. See, in particular:". As such, the article would become a WP:DABCONCEPT stub. The remaining problem is that I do not know any tag warning the editors to not add the tag {{dab}} to a WP:DABCONCEPT article. D.Lazard (talk) 14:22, 15 April 2013 (UTC)
- A hidden note would probably suffice. bd2412 T 15:30, 15 April 2013 (UTC)
- Defining "positive definite" only in terms of bilinear or quadratic forms fails to capture the definition relating to dynamical systems (currently at Positive-definite function) or that of Positive-definite function on a group. Deltahedron (talk) 17:21, 15 April 2013 (UTC)
- I do not agree: I do not well understand the definition given in Positive-definite function on a group, but a bilinear function appears clearly in it (bracket notation). On the other hand, a Positive-definite function is a function whose gradient is zero and the Hessian matrix of second derivatives is definite positive. The fact that some articles are incomplete does not implies that the definition I have given is wrong. D.Lazard (talk) 18:01, 15 April 2013 (UTC)
- I did not say that they were completely unconnected, just that it fails to capture the notion. The characterisation of a positive definite function in terms of positive definiteness of the Hessian is a theorem about positive definite functions that happen to be twice continuously differentiable. Other functions exist. Deltahedron (talk) 18:18, 15 April 2013 (UTC)
- In terms of fashioning an article on this topic, my first question would be whether these dynamic and group functions can be explained under the same heading as the bilinear or quadratic forms. My second question would be, if they are too distinct for such a description, is there a primary topic between them that would be the thing people most likely expect to find when searching for or linking to "positive definiteness". bd2412 T 18:31, 15 April 2013 (UTC)
- I did not say that they were completely unconnected, just that it fails to capture the notion. The characterisation of a positive definite function in terms of positive definiteness of the Hessian is a theorem about positive definite functions that happen to be twice continuously differentiable. Other functions exist. Deltahedron (talk) 18:18, 15 April 2013 (UTC)
- I do not agree: I do not well understand the definition given in Positive-definite function on a group, but a bilinear function appears clearly in it (bracket notation). On the other hand, a Positive-definite function is a function whose gradient is zero and the Hessian matrix of second derivatives is definite positive. The fact that some articles are incomplete does not implies that the definition I have given is wrong. D.Lazard (talk) 18:01, 15 April 2013 (UTC)
- Defining "positive definite" only in terms of bilinear or quadratic forms fails to capture the definition relating to dynamical systems (currently at Positive-definite function) or that of Positive-definite function on a group. Deltahedron (talk) 17:21, 15 April 2013 (UTC)
- A hidden note would probably suffice. bd2412 T 15:30, 15 April 2013 (UTC)
- IMO, Extra dimensions must be merged as a new section in Dimension (mathematics and physics). For Positive definiteness, I suggest to add at the beginning ot the article the sentence: "Positive definiteness is a property of any mathematical object to which a bilinear form or a sesquilinear form may be naturally associated, which is positive definite. See, in particular:". As such, the article would become a WP:DABCONCEPT stub. The remaining problem is that I do not know any tag warning the editors to not add the tag {{dab}} to a WP:DABCONCEPT article. D.Lazard (talk) 14:22, 15 April 2013 (UTC)
- I agree with Einstein's proposition: "Everything should be as simple as it can be, but not simpler". I would say that to the greatest extent possible, we should have articles if an article can be written on a topic, no matter how abstract or nebulous the topic; or, if there is not enough material to justify an article, then a section in whatever article encompasses the topic. However, I am all for innovative solutions, so long as we do not end up having disambiguation pages for topics that are not truly ambiguous to one another. In that vein of thought, what should be done with Extra dimensions, which has been tagged as WP:DABCONCEPT? bd2412 T 13:02, 15 April 2013 (UTC)
- The context is Misplaced Pages talk:Policies and guidelines/Archive 13#Accepting "WP:Multiple-cross-reference page" as a guideline. —David Eppstein (talk) 02:58, 15 April 2013 (UTC)
- They link to it because they are more interested in the general concept than in specific variations of it. But the rules prevent us from having things that look like disambiguation pages but are allowed to have links. Perhaps that indicates a problem with the rules. Perhaps calling it list of positive definite topics would help; after all, the dsiambiguation rules enthusiasts haven't yet succeeded in ruling that lists are too similar to disambiguation pages to be allowed to exist. —David Eppstein (talk) 02:23, 15 April 2013 (UTC)
- Of course, if there is no real meaning to "positive definiteness", it raises the question, why do so many articles link to it? As a disambiguator, I only bring here the disambiguation pages that regularly come up as having the most incoming links requiring repair, in the course of dealing with recurring errors. If the concept is ambiguous, the incoming links need to be fixed. If it is unambiguous, then the appropriate page should be there. If some other solution is appropriate, I will be glad to see it implemented. We are all working together here to correct mistakes such as ambiguous links. bd2412 T 02:05, 15 April 2013 (UTC)
- Very well, and good luck with that. Unfortunately, no one to my knowledge has so far been willing to write an article on "positive definiteness" in general, despite half a decade of prodding. Although most of us know what positive-definiteness means (precisely in some cases, roughly in others), there is apparently no adequate secondary source that links the various cases. So therefore under our WP:PILLARS, no proper article can be written. Yet equally clearly, this should not be a dab page: the uses of the term are each a hair's breadth from each other. I honestly don't know what this means procedurally, but my suggestion is either: (1) leave it as an unsanctioned {{Multiple-cross-reference page}}, or (2) nominate the page for deletion via the standard process. If neither of these options is tasteful to you, then I should remind you that there is no deadline. Eventually the ultimate expert on positive definiteness in mathematics may come along and write an article that adheres to our WP:PILLARS. Until that time, if you notify this Wikiproject (as you have several times in the past about this very issue) you'll have to be satisfied with the responses offered by the idiotic schlubs that occupy it. Sławomir Biały (talk) 01:27, 15 April 2013 (UTC)
- I would not presume the expertise to begin such an enterprise (which is, of course, why I have come here to seek the help of experts in the field). Cheers! bd2412 T 00:33, 15 April 2013 (UTC)
The definition in Positive-definite function on a group (usually a locally compact group) is not quite right; the added B(H) coefficients are unneeded and irrelevant generality. The standard definition from times of yore (say in Dixmier's book on C* algebras, Gelfand-Naimark or Mackey's Chicago notes) is for scalar functions on a group with some mild measurabilty or continuity properties (the usual theorem, from Banach's book and Calvin Moore's papers on Borel cohomology, that a Borel homomorphism on a Polish group is continuous). Certainly for the two articles I wrote on representation theory (zonal spherical functions and Plancherel theorem for spherical functions) the wikipedia definition is not helpful, in fact useless, and misses the point entirely (the Gelfand-Naimark-Segal or the Gelfand-Naimark construction). I don't know how that happened. I am not at all surprised. Mathsci (talk) 20:49, 15 April 2013 (UTC)
- You are, of course, our resident expert on operator theory, so you're undoubtedly correct and this problem should be fixed (by someone...) Sławomir Biały (talk) 00:31, 17 April 2013 (UTC)
Euler's Doodle
I think I can follow most of the allusions in http://www.google.com/doodles/leonhard-eulers-306th-birthday but I am not sure which of Euler's contributions the animated "O" is supposed to illustrate. Any ideas? Tkuvho (talk) 09:38, 17 April 2013 (UTC)
- Euler angles--Salix (talk): 10:04, 17 April 2013 (UTC)
- Yep. Such an animation would be a nice addition to the WP article. --Mark viking (talk) 14:21, 17 April 2013 (UTC)
- That would be nice, but it is not entirely clear whether this is in the public domain. I just looked through their "store" without conclusive results. Tkuvho (talk) 14:35, 17 April 2013 (UTC)
- Google's specific rendition is definitely not in the public domain, but anyone with the ability to make a similar animation is free to do so. bd2412 T 15:24, 17 April 2013 (UTC)
- That would be nice, but it is not entirely clear whether this is in the public domain. I just looked through their "store" without conclusive results. Tkuvho (talk) 14:35, 17 April 2013 (UTC)
- Yep. Such an animation would be a nice addition to the WP article. --Mark viking (talk) 14:21, 17 April 2013 (UTC)
Lucas primality test
Bob Baillie wrote me, asking for help with the article Lucas primality test. In particular:
this wikipedia page http://en.wikipedia.org/Lucas_primality_test does not describe any kind of lucas test at all. instead, it describes pocklington's theorem. the whole article needs to be renamed to something else, and the {{number theoretic algorithms}} template needs to be corrected.
We have Pocklington primality test, LL, and LLR; I'm not sure what should be where and what the best names are. Any thoughts?
CRGreathouse (t | c) 15:13, 17 April 2013 (UTC)
- The Lucas test described in
- Baillie, R. (1980-10). "Lucas Pseudoprimes" (PDF). Math. Comp. 35 (152): 1391–1417.
{{cite journal}}: Check date values in:|date=(help); Unknown parameter|coauthors=ignored (|author=suggested) (help) - seems to be rather different to what the article Lucas primality test claims it to be. The test described in Lucas primality test appears to be an extension of the Fermat primality test (I don't know whether that extension has a specific name). -- Toshio Yamaguchi 16:40, 17 April 2013 (UTC)
- The subject is discussed at length in Hugh Williams (1998). Édouard Lucas and primality testing. Wiley. ISBN 0-471-14852-0. Deltahedron (talk) 06:43, 18 April 2013 (UTC)
Idèle vs idele
Is there a consensus on this? It is under discussion at Talk:Adele ring#Idèle vs idele. Deltahedron (talk) 06:32, 18 April 2013 (UTC)
- Good question. More generally, do we keep or omit accents? In the place or people names, we keep them. What about mathematical terms? -- Taku (talk) 13:46, 18 April 2013 (UTC)
- It would certainly be nice not to have to type them :/ As long as the search function can fuzzily match the two, and that there is no danger of confusion between a word with accented and unaccented characters, I'm not sure there is much to stress about. (Of course, forthcoming examples could prove me wrong.) Rschwieb (talk) 13:44, 19 April 2013 (UTC)
Equation formatting disagreement
There's a discussion going on at Talk:Sexagesimal on how to format some equations. Please contribute. —David Eppstein (talk) 15:35, 18 April 2013 (UTC)
Space Wars
Poincaré group
Sadly, editing patterns usual for nationalistic (and other) PoV pushers apparently are acceptable even in purely scientific articles. This editor not only summarily undid the edit I made for no less than 30 minutes, not only did not he put any notice to the talk: Poincaré group, but his edit summary did not point to any concrete problem with an edit consisting of a lot of changes. Incnis Mrsi (talk) 04:34, 15 April 2013 (UTC)
- Y'all seem to be working it out just fine. You can also start the talk section by responding to the revert's comments. ᛭ LokiClock (talk) 01:53, 16 April 2013 (UTC)
To where do shapes from Euclidean geometry belong?
The article Euclidean geometry should explain the history and traditional methods. But where should actual things from Euclidean spaces be listed: in Euclidean space #Geometric shapes? Or there are better suggestions?
BTW, there is a list of geometric shapes which, as can be seen in its preamble, is devoted to plane shapes only. I feel that the adjective “geometric” is a misnomer in such case. Incnis Mrsi (talk) 17:54, 18 April 2013 (UTC)
- Compounding the problem, there is a List of mathematical shapes which would be better named List of geometric shapes. Perhaps it should be renamed, and the current List of geometric shapes moved to List of planar geometric shapes. RockMagnetist (talk) 17:31, 19 April 2013 (UTC)
- BTW neither henagon nor digon are actually “planar”. IMHO list of two-dimensional geometric shapes would be better. I go to create “list of shapes” as a list of list, for both mathematical lists and not so. Incnis Mrsi (talk) 18:20, 19 April 2013 (UTC)
Is Euclidean space relevant to the definition of a manifold?
Two editors object against replacement of “Euclidean space” with “coordinate space” and “real coordinate space” in the Manifold article on pretexts that complex and p-adic manifolds are unheard of, that Euclidean space is a more familiar concept, etc. I do not think that pushing the “Euclidean space” link wherever a reader is expected to be more familiar with this concept is a good practice. See talk: Manifold #"Euclidean space" or "coordinate space"?. Incnis Mrsi (talk) 16:16, 19 April 2013 (UTC)
“Vector” redirects
I retargeted 10 redirects previously bound to Euclidean vector to other targets. Maybe, hatnotes or some content should be added? Or some of misleading redirects were missed? Incnis Mrsi (talk) 15:15, 21 April 2013 (UTC)
- I redirected Vector component back to Euclidean vector#Decomposition (a different section than previously). A reader who needs information on what a vector component is probably needs a less abstract and more directly applicable treatment than is found in Basis (linear algebra). I will fix Vector components and Component (vector) to point to the same place for consistency. I added a "more info" link pointing to Basis (linear algebra).--Srleffler (talk) 01:07, 23 April 2013 (UTC)
- Going over the rest of your list:
- Physical vector and Vector (physics): I'm not sure that Vector (mathematics and physics) is a better choice than Euclidean vector. If someone is linking to "physical vector" they most likely want the article on Euclidean vectors.
- Vectors and Scalars: I don't have a big problem with this change. Neither target is very good.
- Vector addition, Vector subtraction, and Vector sum: I think Vector space#Definition is an inferior target in this case, for the same reason as for vector component: a reader who needs a link to these concepts likely needs a less abstract introduction to the topic.
- These changes are typical of a problem I have seen with mathematics articles on Misplaced Pages: too damn much of the material is written by and for mathematicians, so that concepts that can be explained simply and directly are instead explained with great generality and abstraction, using concepts and methods that are beyond the level of some readers who might be interested in the topic, and who would have the background to understand it if it were approached differently. The most rigorous explanation is not always the best one pedagogically. Vector components, addition and subtraction are suitable topics for a high school senior, and the directly-linked articles should be at that level, with links to more advanced treatments available from the simpler articles.
- I haven't changed any of the other links yet, so we can talk this through first.--Srleffler (talk) 01:32, 23 April 2013 (UTC)
- These changes are typical of a problem I have seen with scientific articles on Misplaced Pages: too damn much accommodation to “what a reader wants to see”, at the expense of precision. It is not especially important for Vector addition/Vector sum and Vector subtraction, but it is quite important for “components”, because these redirects suggest that these are namely Euclidean vectors which have components, not any others. I would prefer to see Physical vector and Vector (physics) as red links (if only because 4-vectors exist), although we should consult WP:WikiProject Physics about this two targets. Incnis Mrsi (talk) 05:48, 23 April 2013 (UTC)
- I've reverted pending consensus. Vector component is definitely not better explained by Euclidean vector#Decomposition than by Basis (linear algebra). When a reader is required to know the technical details of how decompositions are performed before the formalism of an article becomes accessible, the linking of the article is often the only clue of where to go to decipher things. A simplification is also not appropriate as a redirect, because redirecting implies the article that would be about that subject is under another title, and Euclidean vector#Decomposition is not the article about vector components. ᛭ LokiClock (talk) 09:48, 23 April 2013 (UTC)
- Take another look at the two articles. A reader who is encountering vector components for the first time in high school or first year university is going to find the introduction to Basis (linear algebra) completely impenetrable. In an encyclopedia it is important to treat each topic at the simplest level possible (which varies from topic to topic), before moving into more complicated or abstract aspects of the topic. --Srleffler (talk) 02:23, 24 April 2013 (UTC)
- It's not important to treat things at the simplest level possible, it's important to treat them comprehensively. Encyclopedias are not textbooks. Basis (linear algebra) may be impenetrable, but some things are impenetrable because they're new concepts that you have to take the time to wrap your head around. Having learned from it at high school age, I would say it's semipermeable. Now that it has that nice picture, it's a lot less work. Now, I would be mentally impoverished if all the Misplaced Pages articles I read during that time were subject to every editor's idea of the best way to dumb it down, what I don't need to know, and what my purposes for the information should be. I actually didn't need to understand Euclidean vector components and vector decompositions the most, I needed to know what a basis is and linear combination are. ᛭ LokiClock (talk) 14:21, 25 April 2013 (UTC)
- Simplicity and comprehensiveness are not mutually exclusive. We just need to arrange material and links so that a reader is more likely to find simpler material first, if that is appropriate based on the link they clicked. It doesn't make sense to throw a reader looking for information on vector components to an article on a much more general concept, where the first paragraph of the introduction assumes knowledge of half a dozen concepts that may not be familiar. A high school student who has encountered vectors in physics and math class would be immediately put off by Basis (linear algebra). To even get past the first paragraph, you have to understand the concepts of linear independence, linear combination, vector spaces, free modules, and spanning sets. None of these concepts are likely to be familiar. Redirecting vector component to this article is totally crazy.--Srleffler (talk) 22:09, 27 April 2013 (UTC)
- It's not important to treat things at the simplest level possible, it's important to treat them comprehensively. Encyclopedias are not textbooks. Basis (linear algebra) may be impenetrable, but some things are impenetrable because they're new concepts that you have to take the time to wrap your head around. Having learned from it at high school age, I would say it's semipermeable. Now that it has that nice picture, it's a lot less work. Now, I would be mentally impoverished if all the Misplaced Pages articles I read during that time were subject to every editor's idea of the best way to dumb it down, what I don't need to know, and what my purposes for the information should be. I actually didn't need to understand Euclidean vector components and vector decompositions the most, I needed to know what a basis is and linear combination are. ᛭ LokiClock (talk) 14:21, 25 April 2013 (UTC)
- Take another look at the two articles. A reader who is encountering vector components for the first time in high school or first year university is going to find the introduction to Basis (linear algebra) completely impenetrable. In an encyclopedia it is important to treat each topic at the simplest level possible (which varies from topic to topic), before moving into more complicated or abstract aspects of the topic. --Srleffler (talk) 02:23, 24 April 2013 (UTC)
- I've reverted pending consensus. Vector component is definitely not better explained by Euclidean vector#Decomposition than by Basis (linear algebra). When a reader is required to know the technical details of how decompositions are performed before the formalism of an article becomes accessible, the linking of the article is often the only clue of where to go to decipher things. A simplification is also not appropriate as a redirect, because redirecting implies the article that would be about that subject is under another title, and Euclidean vector#Decomposition is not the article about vector components. ᛭ LokiClock (talk) 09:48, 23 April 2013 (UTC)
- I changed vector addition and subtraction to simply redirect to vector space because the operations are conceptually motivated throughout, as a function of vector spaces being algebras. I left vector sum because it might get confused with elements of the direct sum. ᛭ LokiClock (talk) 09:55, 23 April 2013 (UTC)
- It should not be necessary to explain vector spaces in order to explain the concept of vector addition and subtraction. This is a bad redirect.--Srleffler (talk) 02:23, 24 April 2013 (UTC)
- What? That's all a vector space is, its addition and scalar multiplication. All those figures in vector space are dedicated to explaining what vector addition and scalar multiplication mean intuitively. ᛭ LokiClock (talk) 14:10, 25 April 2013 (UTC)
- You're missing the point. Vector space is a more abstract concept than vector addition and multiplication. Start with the simple; move to the abstract later. You probably didn't learn about vector spaces before you learned how to add and subtract vectors. Why would you expect a reader looking for information on vector addition to have to master this much more difficult subject first?--Srleffler (talk) 22:09, 27 April 2013 (UTC)
- What? That's all a vector space is, its addition and scalar multiplication. All those figures in vector space are dedicated to explaining what vector addition and scalar multiplication mean intuitively. ᛭ LokiClock (talk) 14:10, 25 April 2013 (UTC)
- It should not be necessary to explain vector spaces in order to explain the concept of vector addition and subtraction. This is a bad redirect.--Srleffler (talk) 02:23, 24 April 2013 (UTC)
I support all of the original changes. I'm not sure vector component, component (vector), etc. (in the singular) have a perfect redirect target. Does this mean a component of a vector in a basis, or is it the scalar projection of a vector in some direction (as the term "component" is sometimes used)? Sławomir Biały (talk) 11:33, 23 April 2013 (UTC)
- I don't at present have a position on the current status of things but I would like to register a preference that all links under discussion are chosen in opposition to the principle "too damn much accommodation to “what a reader wants to see”, at the expense of precision."" -- most of these links should go to the most elementary, and emphatically not the most general, treatment of the subject in question. If we're not presenting material a reader at the appropriate level (say, a bright high school student) can understand then we're doing things wrong. --JBL (talk) 14:05, 23 April 2013 (UTC)
- I would oppose redirecting Vector component to Basis (linear algebra).. I would prefer a redirect to somewhere within Euclidean vector (per JBL). There is also the article Vector projection (to which Scalar projection should probably redirect). Mark M (talk) 14:33, 23 April 2013 (UTC)
- “Vector projection” presently has a strong Euclidean bias. If one can reformulate the definition in purely affine terms, specifying that orthogonal projections are a particular case, then it would be a solution. Incnis Mrsi (talk) 07:03, 24 April 2013 (UTC)
- I don't see why it should be done in terms of affine geometry. Is there evidence that this notion of vector projection is more common? Sławomir Biały (talk) 11:10, 24 April 2013 (UTC)
- It should be done in terms of affine geometry because any orthogonal projection is an affine projection, but any skew (affine) projection is not an orthogonal projection; I believe you knew it yourself. Why should I find evidences that the affine projection “is more common”? Or let us rewrite the percentage article in terms of money on the pretext that this notion of percentage is the most common. Incnis Mrsi (talk) 10:16, 26 April 2013 (UTC)
- I'm unaware of any mandate that articles should immediately take the most general perspective possible. A more general notion of projection is already covered at Projection (linear algebra). The article under discussion is about the vector projection in elementary Euclidean geometry. Why is it that you think that readers will expect an article about affine geometry when they type "vector projection" into the search bar? Of the 5000 available on Google books using the term "vector projection", only 36 also include the word "affine". And even in most of those few references, the vector projection is regarded as an Euclidean concept. Sławomir Biały (talk) 11:20, 26 April 2013 (UTC)
- It just means that “projection (linear algebra)” is a possible target for redirecting “component (vector)”, but (the present) “vector projection” is not. Bases do exist in spaces which provide no orthogonality. Incnis Mrsi (talk) 11:29, 26 April 2013 (UTC)
- I think there's something you're still not understanding. We're meant to be a general encyclopedia, and need to accommodate a wide array of readers, many of whom lack mathematical sophistication but for whom an article on Euclidean vector projection is useful. It is extremely uncommon in the literature to use the exact term "vector projection" to refer to anything but the standard Euclidean notion. I'm not arguing that there aren't more general concepts of projection available; for that there are other articles: projection (linear algebra), projection (mathematics). What I'm asking is, what is the evidence that the exact phrase "vector projection" is used to refer to one of these more general notions? If it is not used in this manner, then clearly we should not take the more general perspective. If there are sources that do use it in this manner, then we can assess what relative WP:WEIGHT to attach to those sources. Sławomir Biały (talk) 11:37, 26 April 2013 (UTC)
- It just means that “projection (linear algebra)” is a possible target for redirecting “component (vector)”, but (the present) “vector projection” is not. Bases do exist in spaces which provide no orthogonality. Incnis Mrsi (talk) 11:29, 26 April 2013 (UTC)
- I'm unaware of any mandate that articles should immediately take the most general perspective possible. A more general notion of projection is already covered at Projection (linear algebra). The article under discussion is about the vector projection in elementary Euclidean geometry. Why is it that you think that readers will expect an article about affine geometry when they type "vector projection" into the search bar? Of the 5000 available on Google books using the term "vector projection", only 36 also include the word "affine". And even in most of those few references, the vector projection is regarded as an Euclidean concept. Sławomir Biały (talk) 11:20, 26 April 2013 (UTC)
- It should be done in terms of affine geometry because any orthogonal projection is an affine projection, but any skew (affine) projection is not an orthogonal projection; I believe you knew it yourself. Why should I find evidences that the affine projection “is more common”? Or let us rewrite the percentage article in terms of money on the pretext that this notion of percentage is the most common. Incnis Mrsi (talk) 10:16, 26 April 2013 (UTC)
- Another fine example of the problem of too much focus on the needs of mathematicians. It should not be necessary for a reader to figure out what affine geometry is to get some information on vector components. Vector components is a high-school level topic. Affine geometry is not. --Srleffler (talk) 22:09, 27 April 2013 (UTC)
- I don't see why it should be done in terms of affine geometry. Is there evidence that this notion of vector projection is more common? Sławomir Biały (talk) 11:10, 24 April 2013 (UTC)
- “Vector projection” presently has a strong Euclidean bias. If one can reformulate the definition in purely affine terms, specifying that orthogonal projections are a particular case, then it would be a solution. Incnis Mrsi (talk) 07:03, 24 April 2013 (UTC)
- I am with Srleffler and JBL. Those redirects should go to the elementary articles.
- As for Srleffler's remark that "...too damn much of the material is written by and for mathematicians...", Euclidean vector certainly is not written for mathematicians, neither is vector space for that matter. We just need to figure out how to redirect appropriate audiences to appropriate articles. Mct mht (talk) 10:53, 24 April 2013 (UTC)
Please, contribute to this discussion. In short: a WP:CONCEPTDAB article about vectors could become a long-term compromise. Incnis Mrsi (talk) 11:42, 24 April 2013 (UTC)
Describing vectors simply?
Not related to DABs and all, but there were comments above about basis (linear algebra)/vector space as "impenetrable" or overly abstract... To this end I quickly cobbled two diagrams as you can see on talk:basis (linear algebra)#Diagrams and talk:vector space#Diagrams, if case they're any diagrammatic help... Regards, M∧ŜcħεИτlk 17:26, 25 April 2013 (UTC)
- I think change of basis needs that illustration. ᛭ LokiClock (talk) 12:02, 26 April 2013 (UTC)
- I'll take the liberty of adding them (after slight modifications) to that article. Thank you for pointing this out. M∧ŜcħεИτlk 22:55, 26 April 2013 (UTC)
Euclidean space, Euclidean vector, and inner product space
There is some overlap between these topics. For example, all three should consider the concept of angle. To which extent should first two articles rely on each other? To which extent should both rely on “inner product space”? This is also related to the question immediately above. Incnis Mrsi (talk) 07:49, 25 April 2013 (UTC)
BTW, I just discovered Euclidean subspace, yet another article full of abominations: see talk: Euclidean subspace. Incnis Mrsi (talk) 06:50, 27 April 2013 (UTC)
Polynomial recurrence AfD
The article polynomial recurrence is being considered for deletion. Please add your thoughts here. This article has been discussed at least once before on this page; see this past discussion. Thanks. --JBL (talk) 18:50, 18 April 2013 (UTC)
Marilyn's Cross: a hoax or not?
Someone tagged Marilyn's Cross as a possible hoax. Is it? Michael Hardy (talk) 17:36, 19 April 2013 (UTC)
- I don't know about hoax, but it seems to be original research. GScholar generated no hits and a general Google search turned up little that was not related to the Misplaced Pages article and nothing that could be considered independent. There seems to be a conflict of interest, as editor LMcCormick created the knot and created the article. The history of the editor's talk page suggests that there was controversy about this page. In particular, it was claimed that the editor simply renamed a well-known knot (e.g., Borromean Ring) and substituted their own diagram for an already existing illustration at File:Brunnian-3-not-Borromean.png. It does look fishy. --Mark viking (talk) 18:11, 19 April 2013 (UTC)
- "Marilyn's Cross" is not found in ZMATH. Deltahedron (talk) 19:18, 19 April 2013 (UTC)
None of the above makes it a hoax, but maybe it makes it a mistake. Michael Hardy (talk) 22:32, 19 April 2013 (UTC)
Proposal to delete our article on an axiom of set theory
Please see Misplaced Pages:Articles for deletion/Axiom of global choice. Eozhik (talk · contribs) believes that Axiom of global choice is a hoax. Obviously, I disagree. If you have an opinion on this, I urge you to express it on the AfD page. JRSpriggs (talk) 09:28, 21 April 2013 (UTC)
- The nomination for deletion was withdrawn after considerable discussion. JRSpriggs (talk) 21:38, 22 April 2013 (UTC)
Marilyn's Cross marked with Template:Hoax
An editor has listed Marilyn's Cross in Category:Misplaced Pages suspected hoax articles. Since this appears to be the relevant WikiProject, someone in this project might want to participate in the discussion (if you have not already done so). Hyacinth (talk) 21:16, 22 April 2013 (UTC)
- See the discussion two sections above about this article. It is not clear that it is formally a hoax, but it appears that the author may have given her own name to a common knot and then wrote an article about it. If so, then it would qualify as original research, probably non-notable, and possibly redundant. I am not knowledgeable enough about knot theory to make a definitive call on OR and redundancy, but there doesn't seem to be much in the way of independent reliable sources for this article. --Mark viking (talk) 21:53, 22 April 2013 (UTC)
Domain (mathematics): fixes to ∼ 150 inbound links? Or back to domain of a function with a hatnote?
I do not know what to do with these consequences of those clumsy changes in 2009 (and earlier). And the proposal about deprecation of redirects, which could avoid this kind of situation in the future, also did not attract any support. Incnis Mrsi (talk) 09:26, 23 April 2013 (UTC)
- IMO, the easiest solution is to redirect Domain (mathematics) to Domain of a function, and to add to the latter a hat note For other use of "domain" in mathematics, see Domain#Mathematics D.Lazard (talk) 10:03, 23 April 2013 (UTC)
Kerala fundamental contributions to calculus
It would be interesting to determine whether http://en.wikipedia.org/search/?title=History_of_calculus&diff=551937571&oldid=546717260 is a helpful edit. Tkuvho (talk) 12:26, 24 April 2013 (UTC)
- I'd not give much weight to the source cited there. I have nothing in principle against including mention of the Kerala school there, but adequate sources are needed to give a sense of historical perspective. It's never been clear from more mainstream sources what weight should be assigned to the Indian mathematicians. It doesn't bode well that the source in question claims "imperialist suppression". True or not, this is a classic red flag of fringe science. Sławomir Biały (talk) 14:49, 24 April 2013 (UTC)
"Namesakes"
This edit was done by a user whose most recent edit history does not mention the following:
- List of things named after Archimedes
- List of things named after Thomas Bayes
- List of things named after Augustin-Louis Cauchy
- List of things named after Arthur Cayley
- List of things named after Richard Dedekind
- List of things named after Gustav Lejeune Dirichlet
- List of things named after Albert Einstein
- List of things named after Euclid
- List of things named after Leonhard Euler
- List of things named after Paul Erdős
- List of things named after Fibonacci
- List of things named after Carl Friedrich Gauss
- List of things named after Charles Hermite
- List of things named after Joseph Louis Lagrange
- List of things named after Adrien-Marie Legendre
- List of things named after Gottfried Leibniz
- List of things named after Pythagoras
- List of things named after Srinivasa Ramanujan
- List of things named after Bernhard Riemann
- List of things named after James Joseph Sylvester
- List of things named after Alfred Tarski
- List of things named after Karl Weierstrass
- List of things named after Hermann Weyl
Michael Hardy (talk) 02:46, 26 April 2013 (UTC)
- The new version is neither clearer nor less vague, and also reads awkwardly. I recommend reversion. --JBL (talk) 03:07, 26 April 2013 (UTC)
- I've complained there that it is much more vague, to many people namesake means anything or anyone with a name like Leonhard Euler, and not necessarily named after the mathematician. Dmcq (talk) 03:28, 26 April 2013 (UTC)
I've changed the article's title back to List of things named after Leonhard Euler and commented on the article's talk page about my reasons for this. Michael Hardy (talk) 13:49, 26 April 2013 (UTC)
- Good job. -AndrewDressel (talk) 21:53, 26 April 2013 (UTC)
Organization of the List of things named after Archimedes
I've just organized the List of things named after Archimedes into sections. Further work could probably be done, possibly including alphabetizing, creating subsections of the "Mathematical concepts" section, further refining the organization, and other things. Some of our lists of (pardon the expression) "namesakes" are organized this way, and I think some are not. Some of those that are not might benefit from such work. Michael Hardy (talk) 14:28, 26 April 2013 (UTC)
Help needed on Tessellation
This is a request for assistance on Tessellation, which has been in a scrappy state for some years. There are clearly several aspects of the mathematics of the subject (such as in higher dimensions, and of non-Euclidean surfaces) that need proper treatment with decent visual examples, citations and intelligible explanation. I have done some work on the basics and on the artistic and historical side, but a mathematician's hand is now required. I'm happy to lend a hand where I can. Chiswick Chap (talk) 15:48, 26 April 2013 (UTC)
Reference spam at Pursuit-evasion
An editor at Pursuit-evasion is adding references that are not used in the text and appear likely to be a conflict of interest. Are they sufficiently significant in the history of this topic to keep in the article? If not, could I have some help keeping them out, please? —David Eppstein (talk) 17:30, 26 April 2013 (UTC)
- Ha, and of course one of the references added would be a paper in Chaos, Solitons & Fractals, wouldn't it? --JBL (talk) 22:14, 26 April 2013 (UTC)
- I skimmed the two papers that Chiswick Chap reverted. Both concern differential games with a particular dynamics and constraints and the conditions for successful pursuit. My best guess (I know a little about the field, but am far from an expert) is that these are nice little problems, but are not of fundamental significance to different games theory. The papers themselves don't seem to have any bearing on the article. GScholar shows that each paper has 2 citations, and one was published in 1999. I have to agree, this looks like COI and refspam. --Mark viking (talk) 23:00, 26 April 2013 (UTC)
Hurwitz's theorem and related articles
There are discussions taking place about the article Hurwitz's theorem (normed division algebras) and the redirect Hurwitz algebra. A Hurwitz algebra is synonymous with a composition algebra on which there is an existing article (except that a few authors do not require composition algebras to be unital). However, it is claimed that Hurwitz algebra should not redirect to composition algebra but to the related Hurwitz's theorem (normed division algebras) on the grounds that composition algebra is "inadequate" , and "There is no content in the Composition algebra article" . Comments of expert editors would be helpful at Talk:Hurwitz_algebra and Talk:Hurwitz's theorem (normed division algebras). Deltahedron (talk) 17:09, 29 April 2013 (UTC) Update: Hurwitz's theorem (normed division algebras) has just been moved to Hurwitz's theorem (composition algebras). Deltahedron (talk) 18:16, 29 April 2013 (UTC) Further update: anyone looking for the discussions will need to look at both Talk:Hurwitz's theorem (composition algebras) (plural) and Talk:Hurwitz's theorem (composition algebra) (singular) as something odd seems to have happened to the redirections. Deltahedron (talk) 19:35, 29 April 2013 (UTC)
- As you have noticed, the other editor is a bit prickly, but it is very likely that what they have said is accurate (and he has written a large number of high quality articles). You will get much better results by asking questions and considering the replies. Johnuniq (talk) 03:22, 30 April 2013 (UTC)
- I cannot see that this complaint will serve any purpose, except that Deltahedron might discover that I am among the main content contributors to mathematics articles on wikipedia. I don't accept his claims, which contradict what can be found in standard textbooks. My own view, after having seen him "in action", is that he is not very much in touch with this subject and is being pedantic, while showing almost no interest in adding any serious content. So far in his relatively short wikipedia existence, he has created several short stubs. He apparently has no experience with extended content. Even professionally trained mathematicians have to use sources, in-line citations, etc. Misplaced Pages is not a source and cannot invent its own rules for mathematical naming, particularly for interdisciplinary subjects such as this one, which is extensively used in geometry and analysis. On the talk page of the article I mention three sources—Jacobson, Faraut & Koranyi and Springer & Veldkamp. All of these are solid sources. What I have written conforms to those sources. In addition, apart from looking at many other books and articles, I read through the long and fascinating book of Daniel Shapiro, essentially on just this topic. Shapiro gives a very detailed account of the history in the zeroth chapter. What I have written in the article reflects that history quite closely and accurately. In particular in his second posthumous article, which I have read and which was icidentally proofread by L. E. Dickson prior to publiscation, Hurwitz introduces the representation of the real Clifford algebra that appeared in later treatments (e.g. Eckmann, Lee, Chevalley). If I were less busy with symmetric cones, the article that required a detailed account of Euclidean Hurwitz algebras, I would summarise that zeroth chapter in the current article. Much of the material is already there in the main body, but it would do no harm to mention the more general Hurwitz matrix systems and the corresponding problem for composition of forms. I also think that a "further directions" section right at the end could be worthwhile. Shapiro discusses the applications to vector fields on spheres, Bott generators in K-theory, composition of quadratic forms in arbitrary characteristic, generalizations of composition algebras, algebraic K-theory, and so on. A short summary of what can be found in this long and fascinating book would be nice. It also has Conway's treatment of composition algebras (a sort of Archimedeans talk I assume). There are other similar general sources, e.g. the AMS Notices article by Eckmann. Worrying about whether the octonions are a real division algebra or a composition algebra is hardly the point. When Jordan, von Neumann and Wigner used Hurwitz's work in 1934, it was through the system of Clifford matrices that Hurwitz defined. These mathematical physicists did not use the terminology "Jordan algebras", but the quantum mechanics term "r-numbers". I have no idea why Deltahedron has become side-tracked by these minor and trifling MOS-issues. He appears to be making very few substantial content contributions. I have encouraged him to get some experience of writing an extended article so that he has a clearer idea of the relation between the main body of an article and its lede. That would clarify how we rely on sources for writing wikipedia articles, even in mathematics. Bristling, acerbic or whatever you like, those are the rules. A brief look at WP:DTTR might also be an idea. Thanks, Mathsci (talk) 11:29, 30 April 2013 (UTC)