Wikipedia talk:WikiProject Mathematics/Archive/2010/Oct

List of knot theory topics

I've added some articles to the list (dozens in the past two weeks). That's just clerical work; no need for expertise in knot theory. Next we should think about organizing and maybe annotating the list—dividing it into sections and subsections according to topics, maybe with a bit of commentary. That would take expertise in knot theory, which I don't have. Flexibility in doing that is one of many advantages of lists over categories, but it's not being exploited in this instance. Michael Hardy (talk) 23:04, 29 September 2010 (UTC)

I looked at the list and my first thought is to make a subsection for knots, one for links, one for braids and maybe one for tangles. Then maybe an "Other" section to capture things like the Knot and Khipu type entries? It's going to be tricky as something like Clasper (mathematics) would end up getting listed twice? Do we want to discuss the way to divide the topics? I can write a blurb for some of the topics, but not all of them. --AnnekeBart (talk) 00:10, 30 September 2010 (UTC)

To me it seems that it breaks down into four broad groups: types of knots (trefoil, Borromean link, etc), invariants of knots (bridge number, ropelength, etc), mathematical problems on knots (Gordon–Luecke theorem, Tait conjectures), and operations on knots (Reidemeister moves, flyping). I'm skeptical that Khipu belongs on the list at all: it's mathematics, and it involves actual knots in string, but it's not knot theory. —David Eppstein (talk) 00:19, 30 September 2010 (UTC)

Sounds reasonable to me. You might need a fifth "basic notions" group as well for links to the basics like knot, link, braid, etc. TimothyRias (talk) 08:06, 30 September 2010 (UTC)

I tried to incorporate the suggestions above and did a first pass at just organizing the material. I didn't want to remove anything yet,so the khipu is still there. The list needs to be checked. I'm sure there's a "misfire" here or there. --AnnekeBart (talk) 10:54, 30 September 2010 (UTC)

I did want to mention that I agree with DE. I would suggest removing Khipu and likely Knot and List of knots. This part of the conversation should probably go on the discussion page.--AnnekeBart (talk) 11:03, 30 September 2010 (UTC)

FP delist discussion

File:Shallow water waves.gif, currently listed as a math related featured picture, is currently being discussed for delisting. The discussion is at Wikipedia:Featured picture candidates/delist/File:Shallow water waves.gif, the main objection being that the equations used to generate the image have not been specified.--RDBury (talk) 17:27, 30 September 2010 (UTC)

dead links

Would it be possible to have a bot scan our articles for dead external links, particularly in the references, or is this already done somewhere? Thanks, Ray^Talk 05:11, 24 September 2010 (UTC)

See User:H3llBot/Tasks/2.—Emil J. 13:35, 24 September 2010 (UTC)

It appears that H3llBot only does external links inside citation templates, right? Bare external links such as

• Mathematical Association of America

would not be processed, right? JRSpriggs (talk) 17:58, 24 September 2010 (UTC)

Right, I am in progress of implementing that. I can put Math articles in priority if you want. —  HELLKNOWZ  ▎TALK 10:28, 1 October 2010 (UTC)

Thank you for the offer, but as far as I know mathematics links are no more at risk than other links. JRSpriggs (talk) 20:13, 1 October 2010 (UTC)

Possible merge: Areas of mathematics

Areas of mathematics has been proposed for a merge with Lists of mathematics topics. There was a related thread, Wikipedia talk:WikiProject Mathematics/Archive 63#Outline of mathematics, a few months ago. I'm going to point the 'Discuss' links here since I think this is probably the place to get the best sample of opinions.--RDBury (talk) 09:44, 28 September 2010 (UTC)

Areas of mathematics is merely a list of the American Mathematical Society's Mathematics Subject Classification. if not merged into Lists of mathematics topics, it can probably be deleted or renamed as American Mathematical Society's Mathematics Subject Classification. Mootros (talk) 13:49, 28 September 2010 (UTC)

We already have an article on Mathematics Subject Classification as well. To me Areas of mathematics seems to be something of a copyvio of the MSC. —David Eppstein (talk) 15:25, 28 September 2010 (UTC)

MSC is under CC-BY-NC-SA, which is not exactly a Wikipedia-compatible free licence, but it's not far away.—Emil J. 15:40, 28 September 2010 (UTC)

I think a simple merge isn't going to work since Areas of mathematics has some text which is not about the classification, for example there is a paragraph about what set theory is as opposed to where it falls in the classification. But I do think the material it the article could be distributed into a few existing articles with a bit of care. Stylistically speaking, the title 'Areas of mathematics' isn't correct and starting an article with "Here is ..." isn't right either. So at best the 'Areas of mathematics' article needs a lot of work and perhaps the best thing to do for now is to move the material into other articles and change it into a redirect to MSC or perhaps Mathematics#Fields of mathematics.

Longer term, the 'Mathematics#Fields of mathematics' section is already very long and perhaps it's time to split it off into its own article. Finding a title for such an article that would avoid confusion with Field (mathematics) would be a bit tricky. Outline of mathematics redirects to List of topics in mathematics per another discussion and, as I recall, there are some in this project who'd oppose this title.

We have a number of classification schemes for mathematics; there is a list given at the end of the thread mentioned above. I think the eventual goal should be to make them consistent and remove any unnecessary redundancy. Such schemes have encyclopedic value and are useful for navigation, but we shouldn't be doing any classification schemes that try to do more than that.--RDBury (talk) 22:25, 28 September 2010 (UTC)

Can we clarify what we actually want? Mathematics as a whole, from long division to the Langlands philosophy, can be divided up (say as books in a library would be) considering it as an area of knowledge. Also research published in mathematics is in practical terms divided up (say as a review publication would). That's two separate but obviously not totally independent classifications. The first kind is of interest to anyone who wishes to contemplate three millennia of mathematics as a body of knowledge, the second to those tracking the research of recent decades. There is no real percentage in trying to make classifications of those different types "consistent" with each other: we basically need to have one top-level article about each kind, and in kindness to readers try to explain the relationship. E.g. "analytic geometry" is part of algebraic geometry (and possibly computer graphics), is not a research area as such, and the research area with a similar name is related to complex manifolds. I can see why this discussion may tend to default to Mathematics Subject Classification, but as has been said in the past, we cannot expect that classification to serve all our purposes, and we should keep a little distance from its gravitational pull. Charles Matthews (talk) 06:07, 29 September 2010 (UTC)

Another reason to avoid conflating "Areas of mathematics" with MSC is that the MSC is itself a considerably out of date and convoluted mess, despite recently being revised for 2010. As described by Igor Pak in this mathoverflow thread:http://mathoverflow.net/questions/28334/how-should-the-math-subject-classification-msc-be-revised-or-improved

Perhaps the wikipedia article Areas of mathematics should simply list and discuss the fact that there are different classifications including a link to our own Lists of mathematics topics. 78.148.168.196 (talk) 08:06, 29 September 2010 (UTC)

I think that's a good idea: have that as the article neutrally reporting on various classification schemes. We should respect WP:WAWI in writing about what enWP does. Charles Matthews (talk) 20:54, 29 September 2010 (UTC)

(ui) There doesn't seem to be a consensus on the fate of the article but it does appear there is little support for keeping the MSC material in it. So as a first step (unless there a serious objection) I'm going to move the MSC material to the MSC article; further steps can be discussed later.--RDBury (talk) 05:14, 2 October 2010 (UTC)

Vladimir Drinfeld

A short while ago an IP editor changed information about Drinfeld's nationality (removed Soviet and Ukrainian and added Russian). No evidence or rationale for the change was given. To the best of my knowledge, this is factually inaccurate. I've reverted the change, but it was promptly reverted again by another editor. Extra eyes on that article will be helpful.

PS Looking over his talk page and recent edit history, I see that this is rather typical behavior (possibly, a single-purpose account?), which resulted in disputes and blocks in the past. In particular, I am alarmed by massive changes of the nationality of people born before the October Revolution to "Russian" and by massive depopulation of the category "Ukrainian mathematicians". Arcfrk (talk) 07:28, 29 September 2010 (UTC)

The same IP has gone and changed another one from Ukranian to Soviet since. Obviously they are linked. It is just silly putting people under a wider umbrella like that, even by their own standards they were supposed to be a union of republics not one monolithic country. Are we going to have nearly everyone in Europe put under EC next? It is original research like that one who stuck in those thousands of edits saying every invention in the world was done previously by islamic scholars. Dmcq (talk) 10:06, 29 September 2010 (UTC)

p.s. by the way I('d be quite happy to mark a person as Soviet if they were a Russian born in the Ukraine who self identified as Soviet. Dmcq (talk) 10:09, 29 September 2010 (UTC)

It seem that pre 1917 most of the Ukraine was part of the Russian Empire see History of Ukraine#Russian Empire and Austro-Hungary so some of these people would be technically Russian (eg. Georgy Voronoy, Platon Poretsky) although List of Ukrainians includes everyone born within the modern boundary.--Salix (talk): 11:06, 29 September 2010 (UTC)

Indeed that appears to be the way List of Ukrainians was constructed.Jsqqq777 (talk) 03:00, 30 September 2010 (UTC)

Just to comment: I don't know that there is consensus to dismantle Category:Ukrainian mathematicians and Category:Ukrainian physicists as you currently appear to be doing. Sławomir Biały (talk) 23:22, 1 October 2010 (UTC)

There is no such consensus and there is no such intention on my part.Jsqqq777 (talk) 23:32, 1 October 2010 (UTC)

I'm pretty certain anyone who was born in the boundary and was prominently associated with a Ukranian nationalist organization should not be identified as Russian though, which applies to the next one he identified as 'Soviet' and I reverted. Dmcq (talk) 12:00, 29 September 2010 (UTC)

Was Vladimir Drinfeld prominently associated with a Ukrainian nationalist organization? Jsqqq777 (talk) 08:23, 30 September 2010 (UTC)

My feeling is that if they were born and spent their life within the Russian Empire they should be listed as Russian, regardless of how the borders may have shifted long after their deaths. We wouldn't identify Julius Caesar as being Italian, we'd identify him as Roman. The same principle applies. So Vorony etc should be listed as Russian only. As for Drinfeld, it depends: has he ever held Ukrainian citizenship or did he take US citizenship prior to the fall of the USSR? That is, how strong is the claim that he is Ukrainian? —David Eppstein (talk) 15:09, 29 September 2010 (UTC)

Julius Caesar was a Roman because he was from the city of Rome. Is there someone from e.g. Spain or Britain or Egypt who is identified as "Roman" in their Wikipedia article because they and all their neighbors were subjects of the Roman emperor? Michael Hardy (talk) 17:37, 29 September 2010 (UTC)

Ok, here's a more clear-cut example: we don't say that Constantine I was Serbian. We could plausibly say he was Illyrian but what we actually say is that he was Roman. —David Eppstein (talk) 17:47, 29 September 2010 (UTC)

But he became the emperor. What about, e.g., a philosopher or scientist or poet or something like that? Michael Hardy (talk) 23:05, 29 September 2010 (UTC)

Your repeated goalpost-moving is coming across as resembling the no true Scotsman paradox, but ok. How about Martial. Lede says "Latin poet", nationality in the infobox says "Roman", rather than "Spanish poet" and "Spain". —David Eppstein (talk) 23:16, 29 September 2010 (UTC)

He was a Roman the way Albert Einstein was an American. Let's try a different tack: is it conventional among experts on the history and geography of the Russian Empire to call e.g. Kazakhs "Russians" because they were subjects of the tsar? Michael Hardy (talk) 17:21, 1 October 2010 (UTC)

Please check this Encylopedia Britannica entry about a quite well-known Georgian (not Kazakh, though) general: http://www.britannica.com/EBchecked/topic/48877/Pyotr-Ivanovich-Knyaz-Bagration Jsqqq777 (talk) 19:04, 1 October 2010 (UTC)

But he was a general in the Russian army. Michael Hardy (talk) 03:05, 2 October 2010 (UTC)

Could you not say something like "a subject of the Russian empire, but a Ukrainian nationalist"? JRSpriggs (talk) 15:55, 29 September 2010 (UTC)

That's right -- he was a subject of the tsar and is classified as Russian (general), while being ethnically Georgian (not Kazakh, though, but I don't think you were that specific in your choice of ethnicity). Jsqqq777 (talk) 03:57, 2 October 2010 (UTC)

In most cases we don't state that mathematicians are "citizens of the United States of America", we say that they are Americans. "Subject of the Russian Empire" seems to me similarly longwinded. If Ukrainian nationalism was an important part of the person's life, though, it should be mentioned somewhere. —David Eppstein (talk) 16:20, 29 September 2010 (UTC)

Would it be right then to put 'British Empire' beside Mahatma Gandhi instead of Indian? I had a look at a few other revolutionaries and they seem to say 'allegiance' rather than 'nationality'. Dmcq (talk) 17:51, 29 September 2010 (UTC)

These things can be difficult and contentious. The article on Marie Curie says she was "of Polish upbringing". I believe that at the time Poland was also part of the Russian Empire, and that by the standards David Eppstein suggest above she should be listed as Russian, not Polish. (Where were the borders? Poland did not become independent again until 1918, by which time Curie was a French citizen. Did she ever hold Polish citizenship? I believe she did not.) But sometimes ethnicity trumps nationality. Borders and citizenship can't always be the deciding factors, or else many revolutionaries would be considered as representing the countries against which they revolted. It seems to me that such matters are best discussed on the article's talk page. —Mark Dominus (talk) 23:49, 29 September 2010 (UTC)

My basic position is very simple: we should list people as having the nationality they actually held in their lifetimes, and not give them new ahistorical nationalities that did not exist at the time. If someone was, in their lifetime, a Ukrainian nationalist, then we should say so. But if someone lived in a country that was not at that time the Ukraine, and wouldn't have thought of himself or herself as Ukrainian, we shouldn't let any modern Ukrainian nationalists hijack their identity. —David Eppstein (talk) 23:56, 29 September 2010 (UTC)

I agree with your position. Jsqqq777 (talk) 02:51, 30 September 2010 (UTC)

So was the Ukraine a country or not when it was part of the Union of Soviet Socialist Republics? How about Scottish people in the UK, should they stop calling that a country? I notice for instance Colin Maclaurin has UK citizenship but Scottish nationality in his infobox, perhaps something like that should be done? Dmcq (talk) 08:15, 30 September 2010 (UTC)

I agree with Dominus. There is no hard and fast rule about this sort of thing. Like many such issues on Wikipedia, careful weighing of sources is the way to proceed. As for Drinfeld, the Mactutor biography refers only to his Jewish heritage, his geographical birthplace, and his participation in the IMO on behalf of the Soviet Union. There is no mention of Ukraine or Russia (though arguably our article could at least mention that his birthplace of Kharkov is in modern day Ukraine). Sławomir Biały (talk) 12:04, 30 September 2010 (UTC)

I see no problem mentioning that his birthplace of Kharkov is in modern day Ukraine Jsqqq777 (talk) 13:03, 30 September 2010 (UTC)

It strikes me as more than a little bizarre to say that Drinfeld "is" a Soviet mathematician, in the present tense. Obviously, there are no Soviet mathematicians. You could call him a "former-Soviet mathematician", I suppose, with the hyphen indicating that "former" applies to "Soviet" rather than "mathematician", but that's awkward at best. --Trovatore (talk) 21:15, 1 October 2010 (UTC)

Another way (avoiding the hyphen) would be "formerly Soviet mathematician". Or, for instance, to address the issue of the present tense, " is an American (formerly Soviet) mathematician". Jsqqq777 (talk)

Is it important to have a nationality at all? Could one say something more like: "is a mathematician of Jewish upbringing, born in Kharkov, USSR (present day Ukraine)."? Sławomir Biały (talk) 21:21, 1 October 2010 (UTC)

Is it important that he was born in Kharkov? Is it important that he is of Jewish upbringing (whatever that is)? Jsqqq777 (talk) 21:44, 1 October 2010 (UTC)

Perhaps I should have stated it differently. Do all biographical articles need to begin "So and so a [nationality] such and such..." or can we approach this a different way? In the present case, not only does nationality seem unclear and difficult to succinctly summarize, but reliable sources (as I have already shown above) say "Jewish upbringing" and birth in Kharkov. We should go with what reliable sources say, per usual Wikipedia norms, rather than trying to invent a nationality because of some perceived need to do so. Sławomir Biały (talk) 22:40, 1 October 2010 (UTC)

Clearly, not *all* biographical articles begin with "So and so a [nationality] such and such..."; however, most of them do. Speaking about reliable sources, please check this Encylopedia Britannica entry: http://www.britannica.com/EBchecked/topic/171669/Vladimir-Gershonovich-Drinfeld Jsqqq777 (talk) 23:18, 1 October 2010 (UTC)

Ok. That says "Soviet" (not "Russian" as you were pushing). So, we now have per sources "Soviet", "Jewish heritage", and "born in Kharkov". Sławomir Biały (talk) 23:31, 1 October 2010 (UTC)

Correct. My point is that it does not mention "Ukrainian". So it would be helpful to get a reliable source on that one. Keeping "Soviet", "Jewish heritage" and "born in Karkov" are fine, since all these are corroborated by reliable sources.Jsqqq777 (talk) 23:48, 1 October 2010 (UTC)

I think we need a little common sense on "Soviet", used in the present tense. There are no Soviet mathematicians. There is no Soviet anything. --Trovatore (talk) 23:58, 1 October 2010 (UTC)

That is why you have proposed the hyphen option above to handle the present tense. I'm fine with that.Jsqqq777 (talk) 00:01, 2 October 2010 (UTC)

That was really sort of a "look how bad this would be" kind of thing. I don't really support that; it's unreasonably awkward. --Trovatore (talk) 00:03, 2 October 2010 (UTC)

All right, fair enough. How about "formerly Soviet" then?Jsqqq777 (talk) 00:09, 2 October 2010 (UTC)

I've started a thread at Wikiproject Russia on this SPA's rather worrying editing behavior. Sławomir Biały (talk) 23:40, 1 October 2010 (UTC)

Variation of parameters

Variation of parameters is currently a disambiguation page linking to two articles, one of which does not exist (although I suspect it will soon be created by the person who made it a disambiguation page). Is all of that as it should be? Michael Hardy (talk) 04:28, 1 October 2010 (UTC)

The new title for what used to be variation of parameters is more awkward. The move to the new page was apparently not discussed. It should probably be moved back. Tkuvho (talk) 04:43, 1 October 2010 (UTC)

I think the article variation of parameters (differential equations) should be moved back to variation of parameters. Someone typing "variation of parameters" into the search bar would naturally expect to find differential equations as the primary topic. Difference equations can be linked in a hatnote from this article if necessary, or even better from the text itself since it seems likely that they are closely related. Sławomir Biały (talk) 11:31, 1 October 2010 (UTC)

Now moved back. If variation of parameters (difference equations) is ever created we can refer to it in a hat note.--Salix (talk): 12:01, 1 October 2010 (UTC)

Magic square

There are a number of stub mergers in Category:Magic squares which I believe should be performed:

• Bimagic square → Multimagic square (not yet proposed; we may have enough there to be worth a separate article)
• Trimagic square → Multimagic square (proposed)
• Tetramagic square → Multimagic square (proposed)
• Bimagic cube → Multimagic cube (proposed)
• Trimagic cube → Multimagic cube (proposed)
• Tetramagic cube → Multimagic cube (done)
• Magic tesseract → Magic hypercube (not yet proposed; Magic hypercube and Magic hyperbeam are much too technical at the moment)

Any ideas where to bring this up where it might get whatever attention it deserves. Some of the substubs were PRODed in 2008, and deproded on the grounds that "all mathematical concepts should have articles".

I proposed a version of this Category talk:Magic squares, but that's probably not the right place for discussion. — Arthur Rubin (talk) 17:16, 2 October 2010 (UTC)

Many of these have separate articles in MathWorld and presumably that's why someone created them on WP. The merge* tags have a 'discuss' parameter so theoretically you can put the discussion wherever you want, and though category talks aren't visited much normally, if you put the right links in people should be able to find it. So I don't see why the category talk couldn't be used for a multi-article reorg like this.--RDBury (talk) 02:37, 3 October 2010 (UTC)

Unsolved

There's a discussion about the possible deletion of the {{unsolved}} template that might interest WPM participants, at Wikipedia:Templates for discussion/Log/2010 September 29. Although not per se a mathematics template, it's used in a number of mathematics articles. —David Eppstein (talk) 19:14, 3 October 2010 (UTC)

Wikipedia:Requests for comment/Milogardner

Although this is mentioned above, I want to make sure everyone who has commented above has seen this. Thanks. I've also posted it to Milogardner's talk page as he hasn't responded yet. Dougweller (talk) 15:27, 21 September 2010 (UTC)

What points are needed to be reviewed? I have already agreed that Wikipedia entries must only include well documented scholarly citations that do not "cheery pick". Avoiding "cherry picking" means that when a topic is reviewed by scholars in conflicting manners the conflicts MUST be documented. For example, RMP 41, 42, 43, AND 47 report 100-quadruple hekat, 100-hekat and hekat units in ways that Clagett, 1999, corrected in all cases ... siding with hekat in 4800 hekat in RMP 41. Yet, other scholars conclude that 100-quadruple hekat units were reported .. 4800 quadruple hekat in RMP 41. This is a critical issue. Best Regards, Milogardner (talk) 18:16, 24 September 2010 (UTC)

Not here, please click on the section heading. Dougweller (talk) 18:54, 24 September 2010 (UTC)

The place for your response is at Wikipedia:Requests_for_comment/Milogardner#Response. Note that the RfC is not really the right place to discuss particular content issues like the precise number of hekats. Those are still best dealt with on the talk page of the article in question. Extended discussion about the case shold go on the talk page Wikipedia talk:Requests for comment/Milogardner.--Salix (talk): 19:16, 24 September 2010 (UTC)

The bad editing is still going on. MG really does not understand some of the fundamental issues in this topic. I'm afraid I did really loose my temper on Talk:Rhind Mathematical Papyrus 2/n table. I'm really tired of the arrogant, condescending and pedantic attitude. I do not appreciate being insulted and talked down to. The edit comments [1] are not helping either. There are so many problems with what he's writing it's completely ridiculous:

• The entire point with the fractions in Egyptian math is their use of unit fractions. MG doesn't seem to understand this and keeps claiming we need to report on these n/p and p/q fractions. They didn't even have notation for that.
• His representations of sources are incorrect. There is a continual drive to keep referring to "(64/64) hekat unity" this is his own terminology and is based on a misunderstanding of his regarding modern notation. The ancient scribes never wrote anything like that and this is really clear from the article by H. Vyzamalova.
• In the Akhmim Wooden tablets he claims that Vyzamalova showed that all 5 problems were shown to be correct. That is very clearly not true at all. The author actually comments on "one really bad error" and discusses several others. I have a copy of the paper and it makes very clear that 2 of the problems are consistently done wrong by the ancient scribe. They end up with a correct answer even though the work is wrong. The rest of his description rather royally misses the point of what is going on.
• In older material on the Reisner Papyrus he goes on a bit of a rant against Gillings and some of the statements there are blatantly false.
• Both myself and another editor have had to revert posts to the Rhind Mathematical Papyrus 2/n table which were either wrong or just not helpful.
• Not sure he really gets the point of the RfC. He is still trying to add irrelevant material and goes into long diatribes in the talk pages that do not get to the point. --AnnekeBart (talk) 01:32, 3 October 2010 (UTC)

I'll take this to ANI or AN today. Dougweller (talk) 06:53, 3 October 2010 (UTC)

Sorry for the delay, I've just done this, it is at WP:ANI. Dougweller (talk) 09:27, 4 October 2010 (UTC)

Following the ANI discussion[2] Milogardner (talk · contribs) is banned from editing on the topic of Egyptian mathematics, broadly construed, including talk pages. The ban may be enforced by blocking if necessary. He is now listed on WP:RESTRICT.--Salix (talk): 06:59, 7 October 2010 (UTC)

Talk:Henagon

I am a novice to Wikipedia, so I prefer to discuss in detail any change before actually doing it; feedback and discussion is greatly appreciated.

Consider the following paragraph in the Henagon page:

Most authorities do not consider the henagon as a proper polygon as it is degenerate in Euclidean geometry, its structure is not that of any abstract polygon, and most polygon formulas do not apply to the henagon. For example, the formula for the angle sum of an n-gon, (n − 2)π, does not work for the henagon with n = 1 as the formula would result in an angle sum of − π which is meaningless in this context.

While I don't have statistical data about the opinion of authorities, I think that the rest of the paragraph should be amended. Indeed, the formula for the angle sum of an n-gon cannot be contradicted by a henagon because it holds only for Euclidean geometry, where an henagon cannot be built. The accepted generalisation of that formula to non-Euclidean geometry, where henagons can be constructed, is the Gauss–Bonnet_theorem, where polygons are translated to compact Riemannian surfaces whose boundary is the union of a finite number of geodesics. In this more general setting, it is possible to build polygons with any positive number of edges, and they all satisfy such generalised formula for angle sum. For instance, an henagon can be realised as the boundary of an emisphere, where the Gauss-Bonnet theorem holds: 2π (integral of the curvature in the emisphere) + 0 (integral of the curvature along the boundary of the emispere) = 2π (2π times the Euler characteristic of the emisphere).

It is also unclear how the henagon structure does actually differ from any abstract polygon. Probably the author was referring to the fact that the henagon does not satisfy the axioms for a simplicial complex, which polygons satisfy from n>=3. Also, the word "degenerate" seems to be misplaced here (while it is correct in the Digon page).

My amendment would be to replace the above text as follows:

Most authorities do not consider the henagon as a proper polygon as it cannot be realised in Euclidean geometry and its structure is significantly different from the structure of polygons with at least three edges.

However, there are some properties that are common to all polygons, including the henagon; one example is the Gauss-Bonnet theorem, which constitutes a generalisation of the formula for the angle sum of an n-gon, (n − 2)π, to the non-Euclidean case.

A similar mention of the Gauss-Bonnet theorem might be put in the Digon page, because it would fit the existing example of the Lune. It is interesting to note that the Lune (mathematics) page already mentions the Gauss-Bonnet theorem in the "See also" section, but without any motivation.

Should I go forward and make the modification?

Gianni Ciolli 07:40, 4 October 2010 (UTC) —Preceding unsigned comment added by Gianni.ciolli (talk • contribs)

I have divided the page into sections, to avoid confusing different geometries. You could add something about Gauss-Bonnet as a further section. Charles Matthews (talk) 08:21, 4 October 2010 (UTC)

The phrase "most authorities" is an example of what are called weasel words in Wikipedia. You can add a {{who}} tag to the sentence, try to find a reference yourself, rewrite the sentence to avoid the claim or just remove the sentence altogether. The point is to support statements with specific references rather than to rely on vague generalizations.--RDBury (talk) 09:15, 5 October 2010 (UTC)

Undiscussed move of Euclidean space to Finite dimensional Euclidean space

Just now someone moved Euclidean space to Finite dimensional Euclidean space. Although the latter title might be more precise for a mathematics textbook, certainly the former title is more accessible for a general purpose encyclopedia. Most readers typing Euclidean space into the search bar will implicitly expect to land at the finite-dimensional case, and Finite dimensional Euclidean space is a comparatively unlikely search candidate. Moreover, generalizations (like Hilbert space) can easily be accommodated in the broader article Euclidean space. I suggest that this move be reverted. Unfortunately, the original article has now been replaced with a disambiguation page, so a revert now seems to require admin powers that I lack. Sławomir Biały (talk) 12:50, 5 October 2010 (UTC)

Followup (after Hans' reply): I should add that the article Euclidean space is not very good, and could use some time and energy to flesh it out more. Euclidean space is a top priority article that should give more of an all-purpose overview of things. It's currently rated "B" class, but I think "C" is more appropriate. The article doesn't even have good references, just generic topology (!) references. As an example of the article's deficiencies, Hilbert spaces are only mentioned in passing, Euclidean spaces are only defined in coordinates, etc. So I think the person doing this move can hardly be faulted, but in any case it is still a less than optimal outcome in my opinion. Sławomir Biały (talk) 13:48, 5 October 2010 (UTC)

• I fully agree. The move must be reverted. Hans Adler 13:34, 5 October 2010 (UTC)
• Sure. Boris Tsirelson (talk) 13:50, 5 October 2010 (UTC)
• Move reverted. — Arthur Rubin (talk) 14:46, 5 October 2010 (UTC)

Why nobody notify me until it's moved back? I was watching Talk:Euclidean space but no changes appeared. --虞海 (Yú Hǎi) (talk) 15:21, 5 October 2010 (UTC)

I don't think the general Euclidean space equals to Hilbert space. A general Euclidean space needn't to be complete, but have to be with a real inner product. --虞海 (Yú Hǎi) (talk) 15:28, 5 October 2010 (UTC)

I have certainly seen the convention in the literature that "Euclidean space" must be complete in an infinite-dimensional setting, although I imagine that this is not the only convention. Complete inner product spaces and not-necessarily-complete ones are both strictly more general objects than (finite-dimensional) Euclidean spaces. Anyway, this minor point seems off-topic for what the article Euclidean space should address. The possibility of generalizing to pre-Hilbert spaces as well as Hilbert spaces should be discussed in an appropriate section of the Euclidean space article. Sławomir Biały (talk) 15:39, 5 October 2010 (UTC)

The hyphen in "finite-dimensional" got omitted. Michael Hardy (talk) 15:56, 6 October 2010 (UTC)

Suggested Merger of limit pages

A long time ago I suggested a merger between Limit of a function and (ε, δ)-definition of limit and there was only one comment either way, but mostly the suggestion was unnoticed. And without discussion the tag was eventually taken down. I would be happy to try my hand at merging the two articles if there were any community consensus about it, so I thought I would bring the matter up here to gain a little more visibility. Thenub314 (talk) 06:28, 6 October 2010 (UTC)

Wikipedia often has an elementary version and a technical version articles on the same material, though I don't think the rational for doing this is valid. To avoid content fork issues, it's better to have single article with non-technical descriptions in the first half and more technical material in the bottom half. In this particular case both articles have non-technical and technical material so I'd say there's no question they should be merged.

Apparently we don't have a merge section in either of our article alerts pages. Wikipedia:Pages needing attention/Mathematics#Articles that could be merged has the current list.--RDBury (talk) 06:56, 6 October 2010 (UTC)

I agree with the merger. Hans Adler 12:14, 6 October 2010 (UTC)

While we are at it we can merge them both with limit (mathematics) and limit of a sequence, which merge will deal with both forking and overlap. Tkuvho (talk) 18:07, 6 October 2010 (UTC)

That's a bit more bold and I am not sure if that's a good idea. (Please take this comment literally.) This is standard school material, which could be reason to keep separate things that are often confused in separate articles. A single article on limits might be a good idea, but I could also imagine a large main article on limits that starts with elementary things, has two sections summarising limit of a sequence and limit of a function, respectively, and becomes a lot more technical after that. Of course the creation of such a configuration could also go through a single-article stage. Hans Adler 18:34, 6 October 2010 (UTC)

An even more serious problem with the limit pages (and there are more than 4 of them; see list of calculus topics) is that there is absolutely no history in any of them. This is not helpful to someone actually trying to learn something from these pages. Tkuvho (talk) 19:55, 6 October 2010 (UTC)

Titchmarsh convolution theorem

Can someone deal with the issue I raised at talk:Titchmarsh convolution theorem? Michael Hardy (talk) 16:06, 6 October 2010 (UTC)

Free boundary condition

It appears we have a computer science stub with that name, but a free boundary problem is a well-known boundary condition in partial differential equations, for which we have no article. Any ideas how to proceed? — Arthur Rubin (talk) 21:56, 6 October 2010 (UTC)

Well create a disambiguation page, (preferably by moving the existing page Free boundary condition (image processing) and make Free boundary condition a disambiguation page), and create Free boundary problem. Thenub314 (talk) 22:03, 6 October 2010 (UTC)

Logarithms, again

The logarithms article currently says:

In inferential statistics, the logarithm of the data in a dataset can be used for parametric statistical testing if the original data do not meet the assumption of normality.

Can somebody who knows statistics help me out by explaining or making this sentence more meaningful? Is this meaning more than that there are log-normal distributions which can be "rescaled" to get normally distributed ones? Thanks, Jakob.scholbach (talk) 21:58, 6 October 2010 (UTC)

I see User:Michael Hardy has since removed that sentence, which is certainly better than leaving it in as it was. The use of the log transformation in statistics is widely misunderstood in my experience, so it's difficult to summarise in a sentence, or even a paragraph. There's at least one entire paper about it. There's a bit of info in Data transformation (statistics), but i think it could do with some work. Qwfp (talk) 08:34, 7 October 2010 (UTC)

Community ban enacted on Milogardner

A topic ban banning at WP:RESTRICT.

Milogardner is banned from editing on the topic of Egyptian mathematics, broadly construed, including talk pages

After the RfC/U above had achieved no change, the discussion was taken to WP:ANI where the ban was enacted. Dougweller (talk) 18:22, 7 October 2010 (UTC)

Hmm... —David Eppstein (talk) 05:37, 8 October 2010 (UTC)

The IPs are all from the Sacramento area. This is obvious sockpuppetry: I don't even think an RFCU is needed. Since this is likely to result in further sanctions of the User:Milogardner account, perhaps this should be escalated to WP:ANI right away? I don't know what to suggest doing to prevent a flurry of IPs from continuing to do Milogardner's bidding. Perhaps short term page protection of all Egyptian mathematics articles is warranted? Sławomir Biały (talk) 12:59, 8 October 2010 (UTC)

Oh, let's wait and see on the last item. I see that some of the edits were on October 5, before the ban had officially taken place. Sławomir Biały (talk) 13:03, 8 October 2010 (UTC)

Ok, but WP:DUCK clearly applies, similar edits can be reverted on sight. Dougweller (talk) 13:16, 8 October 2010 (UTC)

Quick correction

Hello, mathniacs. On the talk page for Flux balance analysis, an anom ip user posted that a math statement in the article is wrong. Could we please have someone who actually know anything about matrixes (not me) to check this and correct it if wrong? Thanks. D O N D E groovily Talk to me 13:28, 8 October 2010 (UTC)

It appears that there are several erroneous equations in that article. But which ones are erroneous is not clear to me simply from examining the equations. It seems like someone switched two terms in about half of the equations. JRSpriggs (talk) 14:16, 8 October 2010 (UTC)

Paranormal space

Is this a genuine topological property or a joke? Paranormal space 87.93.147.102 (talk) 09:52, 11 October 2010 (UTC)

This is a term that appears in the literature, so not a joke. See normal space. On the other hand the article is an unsourced WP:DICDEF so an AfD may be appropriate anyway.--RDBury (talk) 11:25, 11 October 2010 (UTC)

It's a good joke but apparently also a legitimate definition due to Eric van Douwen. There is no need for an AfD. We can just merge it into normal space. Hans Adler 11:30, 11 October 2010 (UTC)

(edit conflict) Looks genuine to me - Google throws up several respectable-looking academic sources like this one. It even has an article on Conservapedia, which is not best known for its sense of fun. I imagine the concept of paranormal space bears the same relation to normal space as paracompact space does to compact space. Maybe it gets a good laugh at topology conferences ! Gandalf61 (talk) 11:31, 11 October 2010 (UTC)

You mean at conferences of paranormal researchers and other topologists? Hans Adler 12:22, 11 October 2010 (UTC)

The Conservapedia article is a word-for-word copy of our own. Technically, I suppose this is a violation of our licensing conditions—not that I think we should be too concerned about someone copying less than 30 words from us. But this should not be taken as evidence of notability. Sławomir Biały (talk) 12:37, 11 October 2010 (UTC)

No one (apart friom you) has mentioned notability - the question was whether this is a genuine topological property. Are you saying that you think the article is a hoax ? Gandalf61 (talk) 12:51, 11 October 2010 (UTC)

I think it's generally not a good idea to discuss mathematical notions in terms of notability. We should ask ourselves whether they are important enough to be covered somewhere, and if so, look for the best organisation of the material. Hans Adler 13:19, 11 October 2010 (UTC)

Fine, whatever. My point is that the Conservapedia article is of no value for this discussion. Treat it as a Wikipedia mirror. Sławomir Biały (talk) 13:25, 11 October 2010 (UTC)

The following AMS Proceedings article covers paranormal spaces substantively. That's good enough for me:

• Smith, Kerry; Szeptycki, Paul (2000), "Paranormal spaces under ⋄^∗" (PDF), Proceedings of the American Mathematical Society, 128 (3): 903–908

--Sławomir Biały (talk) 13:31, 11 October 2010 (UTC)

Proposed merger of Symmetric tensor and Symmetric algebra

There is a discussion on whether to merge Symmetric tensor to Symmetric algebra that could benefit from some outside input. Sławomir Biały (talk) 11:31, 13 October 2010 (UTC)

Herman ring

Could anyone please look at, and help to improve, the new article Herman ring? Cheers,  Chzz  ►  05:08, 14 October 2010 (UTC)

Notification: Effective deletion of formal theorem

The article formal theorem has been effectively deleted by an anonymous editor by redirecting it to theorem, without merging anything. I don't know enough about the subject to determine if this action was correct, but since it involves a big content deletion, I thought I would mention it here. There is some (old) discussion about a possible merger on Talk:Theorem. The last version of the article before the redirect is this. Arthena^(talk) 22:38, 13 October 2010 (UTC)

I have made a more proper merge of the content. Greg Bard (talk) 00:41, 14 October 2010 (UTC)

And now I can see why nobody bothered to do anything after the proposal to merge. Dmcq (talk) 11:06, 14 October 2010 (UTC)

There seem to be quite a few editors who were against this merge. It's also very weird to me that the formal account was put first in the article, since this is obviously not the primary notion in mathematics and the sciences. Sławomir Biały (talk) 12:44, 14 October 2010 (UTC)

Well, you've actually put your finger on the reason the formal theorem page came to be in the first place. Greg was POV-pushing the formal notion as primary, on the theorem page. That was entirely unacceptable. Some of what he wrote, though, was appropriate for a page called formal theorem. --Trovatore (talk) 21:21, 14 October 2010 (UTC)

At some point someone in authority at Wikipedia needs to formally correct you and the others about what POV means. All of the content is legitimate, encyclopedic, objectively stated subject matter. What you object to is the placement, or "weight" which you are free to disagree upon. However there is a lot of content in the theorem article which I consider to be long winded blather which passes among the mathematicians because it is that which you are accustomed to dealing. My contributions are actually quite concise, clear and relevant by comparison. We need only look to your revealing statement that the content is appropriate to a differently named article. Why would that make a difference if it was POV pushing IN REALITY? Be well Trov. Greg Bard (talk) 21:54, 14 October 2010 (UTC)

It makes a difference because the POV you are pushing is that the two things are the same. --Trovatore (talk) 22:06, 14 October 2010 (UTC)

We have managed to deal effectively with Milogardner's original research. What's keeping us to do the same with Gregbard's? Sooner or later an RfC/U seems unavoidable. Hans Adler 23:16, 14 October 2010 (UTC)

Hans, there are no "conduct" issues here at all. However your attempt to portray that, when it is not the case supports my conclusion, that you are incompetent to deal with your concerns using civil discourse.Greg Bard (talk) 00:47, 15 October 2010 (UTC)

To Gregbard: Your approach is not just formal, it is formalist. You are treating logic as a content-less game. This removes the motivation which is necessary for most people to be able to learn and effectively use the subject. JRSpriggs (talk) 00:21, 15 October 2010 (UTC)

First of all, there is a sense in which that is exactly what it is. Certainly there are enough legitimate, credible academicians who agree to call it a prevailing view. Second of all it is not POV, is is a method. Trying to portray formalism as POV is just more of the mathemaosis (i.e. disdain for formalism) which I claim consists of POV on your (collective) part. In fact, now that some anonymous coward has reverted the whole effort I have to point out that segregating the content into a separate article portrays more of a POV than including it. Articles are supposed to stand alone, and separating it out does more to portray the concepts as "the way it is" rather than one approach. You guys are too narrow-minded about this. An important article such as theorem should be comprehensive. Greg Bard (talk) 00:40, 15 October 2010 (UTC)

If nothing else, Gregbard needs a RFC/U for his severe civility issues, as illustrated by his gratuitous insults to the anonymous editors ("coward") and to the members of this project ("narrow-minded") illustrated in this comment. —David Eppstein (talk) 03:56, 15 October 2010 (UTC)

You are just avoiding the real issues. Who is this anonymous editor anyway? He is obviously one of you guys from WP:MATH. You have had a year to deal with the merge proposal. No effort has been forthcoming from the group. Now that an effort has been made it was reverted anonymously. Constructive editors make an effort, not just criticize. I have demonstrated my ability to make my contributions and live with the group and its collective attitude. You and the others have not demonstrated any such abilities (with the notable exception of CBM) If Carl is able to interact maturely and respectfully with me and others aren't, that really just supports the conclusion that you aren't living up to your potential for civil constructive contributions. Nothing I have done warrants any intervention AT ALL. Grow up already.Greg Bard (talk) 05:24, 15 October 2010 (UTC)

Although I respect CBM, it's clear that Greg disruptively redefines mathematical terms to mean what he thinks they should mean, regardless of the conventional meaning. It may be that CBM believes it is more important to a achieve an apparent consensus with disruptive editors than a real consensus with the majority of editors. In any case, if CBM is the only one who agrees with you, the logical assumption would be that you're both wrong. — Arthur Rubin (talk) 08:26, 15 October 2010 (UTC)

As for the content, Theorem should summarize Formal theorem, but should also have other content. Merging is clearly unnecessary. I'm sorry I didn't comment at the time, but Greg has done so much damage to Wikipedia that I've found it difficult to keep up. — Arthur Rubin (talk) 08:33, 15 October 2010 (UTC)

I was editing Gregbard's contribution to Theorem to try to make it clearer and less off-putting. Unfortunately, before I had a chance to finish and find out whether Greg would accept that, the whole thing was reverted by Arthur Rubin. JRSpriggs (talk) 08:52, 15 October 2010 (UTC)

I don't see how the articles being combined would be acceptable.

Although there was no objection to the merge (until it happened), there is also no one who agreed that the merge should be made, except Greg and the anon, neither being willing to attempt the merge, until the anon just redirected. May I suggest that we attempt to work from the status quo ante, rather than the disputed status quo? — Arthur Rubin (talk) 09:10, 15 October 2010 (UTC)

I have to say that, in the best-case scenario, I would be happy with a single theorem article that also treats formal theorems, although a formal theorem article to treat them in more detail would also be OK. What is unacceptable is Greg's apparent effort to portray formal theorems as the "more general" notion that should be treated first. They are not in fact more general. --Trovatore (talk) 09:27, 15 October 2010 (UTC)

I have to admit that that appears to have been fixed before I reverted. I agree that iit may be possible for there to be a single article which would be acceptable, provided that Greg is banned from editing it. If he edits it, it's not possible for it to be accurate. — Arthur Rubin (talk) 09:49, 15 October 2010 (UTC)

This is a highly excitable group, prone to high rhetoric. The only disruption was by the anonymous editor who deleted a whole article worth of content (as is evidenced by the title of this section), the content of which no one has any problem. I am perfectly willing to go along with Trovatore's concern about not portraying the formalized account as more general. However the content of the account is just fine, as you all seem to agree. Even now that Arthur has re-evaluated himself, he now admits that things are so bad as first portrayed. This is not the first time Arthur has had to re-evaluate his own rash judgment of my contributions. Everybody just calm down and behave constructively.Greg Bard (talk) 13:57, 15 October 2010 (UTC)

I have reverted Arthur's revert of JSpriggs efforts to improve the merge. I think Arthur's action would qualify as a real "disruption" of productive editing than anything that can be attributed to me. I am sorry that I have felt it necessary to call people "narrow" or "coward," however at this point I think we need to look into the validity of that criticism. Greg Bard (talk) 14:07, 15 October 2010 (UTC)

And I find it difficult to recall an edit of Greg in articles related to mathematics which was not disruptive. However, it's possible this could be edited into a sensible article, which might then be properly split into formal theorem and theorem. I'm willing to give JRSpriggs the benefit of the doubt. — Arthur Rubin (talk) 14:51, 15 October 2010 (UTC)

This is the type of high rhetoric and dramatizing that destroys your credibility Arthur. You might as well call me a "Wikipedia terrorist." You don't just go off the deep end, you nuke the whole pool. You always manage to get personal in the edit summaries too. You should be embarrassed and ashamed of your arrogance. Grow up Arthur, seriously. I don't expect a lot of thanks for my contributions, but I do not deserve these attacks , and I don't come close to deserving it. Greg Bard (talk) 14:59, 16 October 2010 (UTC)

Uh, look to thine own house, Greg. You are quite capable yourself of flinging high rhetoric and drama ('coward' etc.) when it suits you but the first one to cry foul and witter on about what a Good Faith Editor you are whenever anyone challenges or criticizes you. The very hypocrisy. I think you are the one who needs to grow up. 72.74.204.175 (talk) 19:03, 16 October 2010 (UTC)

Is a vortex a solution of certain differential equations of fluid dynamics, or is a vortex made of water (or the like....) swirling around? Likewise, is a theorem something that satisfies a formal mathematical model of what theorem are, or is a theorem a statement that people can understand, and that they have proved? One should not mistake the formal mathematical model of the thing for the thing itself. Michael Hardy (talk) 15:18, 16 October 2010 (UTC)

Well it's an excellent point. However I do make a point of including the type-token distinction so as to clarify these points in the article, but your brethren ideologically delete it. So either clarify these type of points in the article completely the way I do, or do not cry about it when the aftermath looks like POV.Greg Bard (talk) 21:23, 16 October 2010 (UTC)

I would prefer to leave the type-token distinction in the definition of "formula"/"well-formed formula". It just adds distraction, here. — Arthur Rubin (talk) 21:45, 16 October 2010 (UTC)

Arthur I am open minded to this approach, provided that the articles to which these foundational concepts actually cover the foundations. For instance, I do not feel it is necessary to state in Set (mathematics) that some people think sets are abstract objects and others think it is a mental representation, provided that the article set (math) actually identifies itself as a concept, an article which deals with that distinction.

However once we do enter into the formalized account of a theorem, there is no crying about pushing a formalist POV. Just word it (as I have) such that it states that theorems "can be expressed in formal language" rather than saying "are entities of a formal language." Otherwise what you are doing is pushing an anti-formalism POV. That is, in fact what is going on here folks. I am under no "formalist" illusions at all, but you all seem to be unaware of your own fervent anti-formalism. Greg Bard (talk) 22:01, 16 October 2010 (UTC)

You must not be familiar with Rubin's work if you think he's anti-formalist! I tend toward Platonism myself, but that's the luxury of staying in number theory. CRGreathouse (t | c) 23:04, 16 October 2010 (UTC)

Then I have unfairly characterized Arthur as anti-intellectual in a way that is different than the anti-intellectualism some of the others are engaging in. So in fairness, I must observe that it wasn't Arthur who is responsible for the "effective deletion of formal theorem" which was the precipitating event of this discussion. He merely has taken it as an opportunity to delete other material I worked on.

The the type-token distinction does help address the concerns the anti-formalists are crying about, so he is not helping that situation. Recently he has taken to deleting the diagram explaining the relation of strings of symbols of a formal language, well-formed formulas, and theorems very dismissively. He isn't helping to build anything, he just deletes without any attempt to reformulate or explain himself. We have to go through a phase of high drama each time an issue comes up, and then things cool down (as they have currently). It's just getting old.Greg Bard (talk) 23:27, 16 October 2010 (UTC)

I'll admit, I've never liked that diagram, though I think a nicer version would be a good addition to the appropriate article (I'm not sure what that would be in light of the present discussion). I did some work in this precise field: counting or listing wffs, theorems, and antitheorems in Richard Schroeppel's metatheory (or rather, just the classical part; I've always meant to go back and look at the intuitionistic theorems). CRGreathouse (t | c) 01:34, 17 October 2010 (UTC)

It would be nice if Greg could provide the real reference. There isn't a "Hofstadter 1980", at least according to amazon.com. — Arthur Rubin (talk) 02:14, 17 October 2010 (UTC)

I am pretty sure that refers to the well known Pulitzer Prize winning Godel Escher Bach.Greg Bard (talk) 02:26, 17 October 2010 (UTC)

I'm pretty sure it was intended to, but that would be 1979 or 1999, rather than 1980. — Arthur Rubin (talk) 02:31, 17 October 2010 (UTC)

(EC) It is very bad form to source a specific claim to a long book and not to provide a page number where that claim may be found. It is even worse form to supply the wrong year for the book and no title. GEB was published in 1979, or at least so says our article on it. —David Eppstein (talk) 02:34, 17 October 2010 (UTC)

Rubik's cube FP nomination

File:Rubik's cube.svg has been nominated for featured picture, see Wikipedia:Featured picture candidates/File:Rubik's cube.svg for the discussion. A slightly different version of this, File:Rubik's cube v2.svg, is used in the {{Groups}} template and so appears in dozens of articles.--RDBury (talk) 22:27, 14 October 2010 (UTC)

Logarithm up for Good Article Nomination

I nominated logarithm for WP:GAN. Anyone interested in a mostly basic, yet colorful (, , ), and highly watched topic, please review the article now! Thanks, Jakob.scholbach (talk) 13:50, 16 October 2010 (UTC)

Edit war over blackboard bold

An editor recently changed the ordinary bold into blackboard bold at SL2(R) contrary to our manual of style. I reverted this edit, and was subsequently reverted twice by the same editor on the WP:GAMEy grounds if IAR. This is the first time I've ever seen IAR as grounds for an edit war, but anyway clearly outside input is needed to resolve the dispute. Sławomir Biały (talk) 15:51, 16 October 2010 (UTC)

This accuse is non-sense. I have reasons to use WP:IAR. See Talk:SL₂(R)#Blackboard bold discussion. And I'm board of Sławomir Biały's "alway change the place of talking to let me not aware of the ingoing discussion". ––虞海(Yú Hǎi) 15:55, 16 October 2010 (UTC)

You're obviously not on top of not accusing other editors of bad faith. Dmcq (talk) 16:09, 16 October 2010 (UTC)

Only if one's action have already made substantial one me and do that once and once again after I told one not to. ––虞海 (Yú Hǎi) (talk) 16:35, 16 October 2010 (UTC)

And even in this case I did not say he delibriately did that. But I'm BORED of that method. ––虞海 (Yú Hǎi) (talk) 16:36, 16 October 2010 (UTC)

Let's confine discussion of the issue to Talk:SL2(R). Please WP:AGF. CRGreathouse (t | c) 16:55, 16 October 2010 (UTC)

Thank you! ––虞海 (Yú Hǎi) (talk) 17:00, 16 October 2010 (UTC)

Gaps template

In long and short scales, among other articles, an editor is using {{gaps|1|000|000}} (etc.), instead of 1,000,000 as specified in the MOS. I've fixed that article, but is it possible for a bot to make those substitutions in certain articles, AWB to have an option to substitute those, or even a {{fake gaps}} templates which replaces the spacing command in {{gaps}} by simple commas? AWB would be best, except I seem to have a virus attacking my IE, so I can't run AWB on any of my computers at the moment. — Arthur Rubin (talk) 04:28, 17 October 2010 (UTC)

WP:MOSNUM does require the use of commas to delimit groups, it merely suggests it as an example and forbids the use of full stops for this purpose. It even mentions the use of {{gaps}} as an alternative.TimothyRias (talk) 07:13, 17 October 2010 (UTC)

Point taken. In long and short scales, however, the editor in question changed the format from the established 1,000,000 (or $1,000,000\,$) to {{gaps|1|000|000}}. Besides 1000000² is just wrong. — Arthur Rubin (talk) 08:08, 17 October 2010 (UTC)

Mathematics Genealogy Project

We have a bit of an edit war going on at Mathematics Genealogy Project. One editor seems to have an axe to grind against the project and is adding original research and misquotes of sources as criticism of it. More eyes welcome. —David Eppstein (talk) 16:40, 17 October 2010 (UTC)

I don't know why a critique of that data base must be censured. If you had invited members of WikiProject Mathematics to look at the discussion page of the MGP w/o your advocacy ("axe to grind") and prejudicial comments "adding original research" and "misquotes", perhaps the "more eyes welcome" could indeed take a neutral look at the issues at hand and improve the article where necessary.Edstat (talk) 00:41, 21 October 2010 (UTC)

Pentagon construction FP nomination

File:Pentagon construct.gif has been nominated for featured picture, see Wikipedia:Featured picture candidates/Construction of a regular pentagon for the discussion.--RDBury (talk) 11:22, 20 October 2010 (UTC)

Herman ring

Did you know... that I cannot think of a good WP:DYK tagline for Herman ring?

Please could anyone help suggesting a good 'Did you know...' tag so that this can appear on the main page.

Please see the entry, here.

Of course, if anyone can help improve the article that'd be great too; it is a new article, written by a new user. It is somewhat tricky for the layman to follow, and I'm therefore struggling a bit.

Help greatly appreciated.  Chzz  ►  18:42, 20 October 2010 (UTC)

For a DYK? it's going to have to be fairly simple, since those go to the front page. Maybe tie it in with fractals or (because it's timely) the Mandelbrot set? "DYK that, xx years after Benoit Mandelbrot invented..."? CRGreathouse (t | c) 18:51, 20 October 2010 (UTC)

Constance Reid (1918 – 2010)

Constance Reid died last week. Might this be an occasion for some attention to the article about her? Michael Hardy (talk) 21:07, 20 October 2010 (UTC)

Linear Least Squares

FYI, the usage of Linear least squares is under debate, see Talk:Numerical methods for linear least squares.

76.66.198.128 (talk) 03:53, 21 October 2010 (UTC)

Help needed with a suspected hoax

Another editor brought the Alexander Chain article to my attention as a potential hoax, and, having reviewed it, I tend to agree (no sources, dubious relation to chain rule, impossible "facts", etc.). I am going to AfD this article, but thought that an additional review by mathematicians wouldn't hurt; just in case. Help would be greatly appreciated.—Ëzhiki (Igels Hérissonovich Ïzhakoff-Amursky) • (yo?); October 20, 2010; 18:32 (UTC)

Hilarious: Alexander Chain, inventor of the Chain rule. This should not be deleted, this should be redirected to a serious article related to Alexander chains. I have forgotten everything about them other than that they exist. Hang on while I browse some topology books. Or maybe someone less clueless than me reads this and is faster? Hans Adler 19:51, 20 October 2010 (UTC)

What a pity. It appears there are no Alexander chains, after all. Not even Alexander-Whitney chains. And the hoax is in fact strictly centred around the chain rule. Hans Adler 20:00, 20 October 2010 (UTC)

Maybe Zhetysu would do. — Carl (CBM · talk) 20:17, 20 October 2010 (UTC)

That's a good variant.GreyHood ^Talk 20:34, 20 October 2010 (UTC)

There's Alexander-Spanier cohomology, so presumably one can speak meaningfully of Alexander cochains.Sławomir Biały (talk) 21:44, 20 October 2010 (UTC)

I think he's a relative of Karl-Heinz Normal (famous for the Normal distribution, the Normal subgroup, Normal operators, Normal vectors, Normal curvature, Normal extensions,.....). Michael Hardy (talk) 21:11, 20 October 2010 (UTC)

....and also of Victoria Cross (noted for Cross products and Cross-ratios, but also worked on word puzzles and country running). Michael Hardy (talk) 21:13, 20 October 2010 (UTC)

Five points will be awarded to the first to identify the person I plagiarized these puns from. Michael Hardy (talk) 21:13, 20 October 2010 (UTC)

Tales of Forgotten Genius

“ Montmorency Royce Sebastian Carlow (1878–1927). The son of a Buckinghamshire peat-digger, he was born in the sedate village of Gossoon two years after Alexander Graham Bell's invention of the telephone, and died the year Lindbergh flew the Atlantic. Montmorency Carlow's contribution to science is no less striking. He displayed no noticeable mathematical talent – indeed no talent at all worth speaking of – until the age of forty-eight, when he succeeded in destroying the entire village of Gossoon, and much of the surrounding countryside, in a singelhanded air-raid mounted from a Handley Page 0/400 Night Bomber. At his subsequent trial, he offered the defence that he was attempting to estimate the area of Gossoon's village pond by calculating the proportion of hits from a random bombing pattern; adding that since the total area of Gossoon was 946.32 acres and he had hit the pond exactly once using 143 bombs, the area of the pond was approximately 6.6176224 and a bit acres. Lord Justice Milnesshawe-Ffeebes, failing to appreciate the revolutionary nature of the method, commented that since the bomb crater had obliterated all trace of the pond, the calculation left something to be desired. Before the conclusion of the trial, Carlow attempted to estimate the probability of surviving a fall by repeatedly jumping from a high window, fell on his head at the first attempt, and broke his neck. His name lingers on, however: the techniques of estimation that he pioneered are known throughout the world as Monty Carlow Methods. ”

— plagiarized from the same source as the other items above. Michael Hardy (talk) 21:27, 20 October 2010 (UTC)

Clarification: I meant the other items that I posted above, not the one about Chain's Rule. AFAIK that's not plagiarized. Michael Hardy (talk) 21:30, 20 October 2010 (UTC)

If you were amused by the "Chain rule" hoax, then you may like this: Patrick Billingsley's Weak Convergence of Probability Measures (pages 273) credits the "Portmanteu theorem" to this article:

• Portmanteau, Jean-Pierre (1915). "Espoir pour l'ensemble vide? [Hope for the empty set?]". Annales de l'Université de Felletin. Vol. CXLI. pp. 322–325. {{cite news}}: Cite has empty unknown parameter: |1= (help)

Thanks! Sincerely, Kiefer.Wolfowitz (talk) 01:05, 21 October 2010 (UTC)

Thanks very much indeed for pointing this out, I had not realizedThe Mathematical Intelligencer had put an archive of old editions on the web. By the way I believe the author later left mathematics to help found a rock group ;-) Dmcq (talk) 11:27, 21 October 2010 (UTC)

Dmcq is hereby awarded the abovementioned five points. Michael Hardy (talk) 00:12, 22 October 2010 (UTC)

Machtey & Young's Introduction to the General Theory of Algorithms uses the common word "dovetail" for some technical concept and attributes it to "Wood U. Dovetail". Michael Hardy (talk) 00:08, 22 October 2010 (UTC)

Overlap of boxes in Square root of 2

In Square root of 2 and a number of other such numbers a box has been put in which overlaps and obscures the contents list if you don't have a wide page. I think the box should be smaller anyway, but what's the best trick to stop any overlap of boxes like that without stopping them being side to side on wider screens? Thanks. Dmcq (talk) 12:38, 21 October 2010 (UTC)

I have put the TOC before the infobox template. That seemed to fix the issue. Sławomir Biały (talk) 13:51, 21 October 2010 (UTC)

Thanks very much, I'd never have thought of that. Dmcq (talk) 15:28, 21 October 2010 (UTC)

Real-world calculation of logarithms

Does anyone know what algorithms are typically used in programming languages etc. to calculate logarithms? (We have Binary logarithm#Algorithm, but I'm not sure this is how it is actually done). Thanks, Jakob.scholbach (talk) 20:08, 12 October 2010 (UTC)

See Natural logarithm#Numerical value and use the fact that $\log _{a}b={\frac {\ln b}{\ln a}}\,.$ JRSpriggs (talk) 21:42, 12 October 2010 (UTC)

Thanks—both awesome and embarassing that I didn't see this myself. Jakob.scholbach (talk) 21:52, 12 October 2010 (UTC)

Looking through the glibc source code it seems to be quite close to that described in Binary logarithm#Algorithm, integral binary algorithms certainly play a part, there also seems to be a "Reme algorithm" to generate a polynomial optimised to reduce the error on a restricted range. Other bits which appear include some lookup tables and there is also a newton iterations to solve for y: exp(y)-x=0, in the worse case scenarios where the accuracy is not good enough.--Salix (talk): 23:10, 12 October 2010 (UTC)

Regarding applying Newton's method to the exponential function, please see my criticism at Talk:Natural logarithm#Subsection on high precision calculation of the natural logarithm. JRSpriggs (talk) 05:06, 13 October 2010 (UTC)

It occurs to me that one could pre-calculate some values of ln to high precision and use them in a subroutine which calculates the natural logarithm. For example, pre-calculate ln(2), ln(3/2), ln(5/4), ln(9/8), ln(17/16), ln(33/32), ln(65/64), and ln(129/128). Suppose we are given a number x as input. Initialize the output to zero. Shift x into the range from 1/2 to 1 while adding (subtracting) ln(2) to the output for each bit which x was shifted downward (upward). Then if x<2/3, multiply x by 3/2 (just a shift and add) and subtract ln(3/2) from the output. If x<4/5, multiply x by 5/4 (just a shift and add) and subtract ln(5/4) from the output. Similarly for 8/9, 16/17, 32/33, 64/65, and 128/129. Then 128/129≤x≤1 is close enough to 1 that the power series for ln(x) should converge rapidly. Add the (negative) series sum to the output and return that. JRSpriggs (talk) 17:02, 22 October 2010 (UTC)

Infinity

Take a look at what the article titled web page currently looks like. Michael Hardy (talk) 21:07, 14 October 2010 (UTC)

Thanks. That was one of the few times that I really had to laugh about something on Wikipedia. Maybe we can employ a similar technique for self-similarity or even adapt it to fractal? Hans Adler 21:14, 14 October 2010 (UTC)

Please have a look at 'Limited infinity' in Infinity —Preceding unsigned comment added by 78.146.59.36 (talk) 14:50, 22 October 2010 (UTC)

? The expression "Limited infinity" does not appear anywhere in the Infinity article. You might want to clarify your suggestion.—Emil J. 15:06, 22 October 2010 (UTC)

Tangram GA nomination/List of math websites?

I started a review for GA status for the Tangram article, and I think it's just about there but it would be nice to have a third person take look at it. One issue is whether archimedes-lab.org should be considered a reliable source. More generally, I think it would be helpful to have a list of the best on-line math sites with consensus driven indications as to whether they are suitable to be used as a reference. This would save time since it would avoid having to repeat making a decision on reliability for each article where a reference is used. I've been keeping a list of shortcuts on my user page but I was thinking of something more user friendly to be linked from the project or portal page.--RDBury (talk) 11:12, 22 October 2010 (UTC)

Degree of a polynomial

What should the article titled Degree of a polynomial say about the use of the words "degree" and "order"? Merely that they are synonyms? That in the present day "degree" is standard? Or what? Michael Hardy (talk) 18:52, 22 October 2010 (UTC)

I like the present version, which says

In some older books, the word order is used.

but does not otherwise mention it.

CRGreathouse (t | c) 19:42, 22 October 2010 (UTC)

Frege

A fellow is pursuing a suprising agenda at talk:Gottlob Frege‎, I would appreciate if interested parties could take a look. Tkuvho (talk) 19:40, 24 October 2010 (UTC)

ANOVA and "due to"

Given that ANOVA appears to be an important topic (based on the ratings and views stats), perhaps someone here cares to comment on this issue. I see that Oscar Kempthorne had strong views in this area, but I'm unsure if those were mainstream or not. Tijfo098 (talk) 05:21, 26 October 2010 (UTC)

Weird notation in elliptic integrals

Could a few people keep an eye on Elliptic integral and Angular eccentricity. An anonymous IP is repeatedly trying to insert a very weird and nonstandard symbol $o\!\varepsilon$ <math> o\!\varepsilon</math> that he has apparently invented into these articles. This might be some sort of strange hoax: they claim the symbol is called "grethyl". r.e.b. (talk) 14:02, 22 October 2010 (UTC)

A google search for "grethyl" turns up this: http://img411.imageshack.us/img411/3694/grethylfinal.jpg

Some esthetic merits, but nothing to support the IP's claim. Michael Hardy (talk) 18:57, 22 October 2010 (UTC)

No, I am the one that introduced $o\!\varepsilon \,\!$ way back when, not that IP, and it is not a hoax. If you had clicked on ligature œ, you would have seen that it is not so weird:

"In medieval and early modern Latin, (oe) was used

to represent the Greek diphthong οι..."

If you make it a ligature, it looks just like ${\color {white}_{.}}\alpha {\color {white}^{.}}\,\!$: ${\color {white}|}o\iota \,\!\!\to \,\!\!o\!\iota \,\!$.

When you also take into account that "e" is an accepted proxy for "ε", $o\!\varepsilon \,\!$ is far from "idiosyncratic" and quite appropriate as a denotation, in this situation. P=)

As such, I've reverted it, with a better clarification (and, of course, it is, and always has, noted early on in its article that $\alpha \,\!$ is the traditional denotation), as well as doing some cleanup. ~Kaimbridge~ (talk) 01:44, 24 October 2010 (UTC)

Wikipedia is not the place to try to popularize new nonstandard notations: see WP:SOAP. —David Eppstein (talk) 01:53, 24 October 2010 (UTC)

It looks like the notation has been stuck into a number of articles like Spheroid and Latitude dating back to four years ago. If somebody knows how to do a literal search for the string I think that would be a very good idea. Why anybody wanted to do such a silly thing I don't know. Dmcq (talk) 09:13, 24 October 2010 (UTC)

Well sometimes there is an inherent conflict where that can't be helped and, as pointed out, this wasn't just recently thrown in as a "silly thing" and these articles have survived many subsequent, unrelated edits by more sanctioned editors without any complaints!

I just reverted angular eccentricity to the previous version, excluding the disputed $o\!\varepsilon \,\!$: You are saying this doesn't foster ambiguity and confusion? ~Kaimbridge~ (talk) 12:44, 24 October 2010 (UTC)

There are a number of unrelated issues with the version you reverted to. First, rather than rendering simple inline formulas in html (as in a) or in ordinary <math>-mode (as in $a$), the edit forces PNG rendering of all inline formulas (as in $a\,\!$). This is not in accordance with our manual of style for mathematics that recommends against inline formulas that render as PNG. Second, the discussion of LaTeX in the lead paragraph is quite out of place. There is no need to dwell on notational trivialities at all in the article, much less in the lead which is where the most important stuff is supposed to go. Third, I don't know why eccentricity was changed into ε everywhere. The standard symbol is e. Sławomir Biały (talk) 13:25, 24 October 2010 (UTC)

Myself, I think it would help your case if you could find a reference that uses this symbol. Ozob (talk) 13:28, 24 October 2010 (UTC)

This strange notation was also inserted into Elliptic integral, Angular eccentricity, Spheroid, Latitude, Ellipsoid, Reference ellipsoid, Prolate spheroid, flattening, Eccentricity (mathematics), Radius of curvature (applications), ellipse, circumference, Longitude, List of Solar System objects in hydrostatic equilibrium, quarter period, Jacobi's elliptic functions. I've removed it from these, but there are probably other articles I've missed. It might be a good idea if a few editors added these articles to their watchlists for a while. Also some of these articles could do with further cleanup, as they sometimes contain strange opinions. r.e.b. (talk) 15:31, 24 October 2010 (UTC)

Sorry I shouldn't have described it as silly. It was thought through but I believe it is a bad idea to introduce new symbols, especially in Wikipedia which is supposed to summarize what others do and also as this symbol is a hard to pronounce and sounds like somebody warning a person off. There is no real problem with 'e' that required solving. (Incidentally I've just read students remember things better if one makes the font less readable, I don't think I'll advocate this for Wikipedia though!) Dmcq (talk) 20:40, 24 October 2010 (UTC)

Are you-all talking about the "oi" sound from "moist" and "coin"? If it is some other sound, please provide at least two example common words which contain it. JRSpriggs (talk) 04:29, 25 October 2010 (UTC)

I believe that's it, as in 'Oi!, you there!, stop that' :) Dmcq (talk) 17:40, 25 October 2010 (UTC)oe

I just looked it up and seemingly in English it is pronounced more as in the initial e in federal or as the end of diarrhoea and in the phonetic alphabet it is more like eu in the French neuf.

To Dmcq: Thank you. JRSpriggs (talk) 21:17, 25 October 2010 (UTC)

Waiiiiiit a minute, now. This is directed particularly at you, R.e.b.: Is your objection just with $o\!\varepsilon \,\!$ or $\varepsilon \,\!$ in general as being nonstandard? If it is the latter, then you need to get a grip, as $\varepsilon \,\!$ is an established and acceptable notation for eccentricity. Ellipse even acknowledges it:

The eccentricity of the ellipse is

$e=\varepsilon ={\sqrt {\frac {a^{2}-b^{2}}{a^{2}}}}={\sqrt {1-\left({\frac {b}{a}}\right)^{2}}}$

If someone who is mathematically proficient is asked what does e mean, I suspect the first response would most likely be "2.718281828459...". I think e is mainly preferred because it is basic text. If you don't want to use it, fine. But don't get rv happy just because someone else does! ~Kaimbridge~ (talk) 02:13, 27 October 2010 (UTC)

The symbol $\varepsilon \,\!$ is indeed standard. I have no objection to it and as far as I know I have not changed it. My objection is entirely to the new symbols you have invented by merging a couple of other symbols. While I agree that standard notation is sometimes not entirely satisfactory, inventing new symbols just makes things worse (and also violates wikipedia policy; see WP:NOR). The best thing to do is to use the most common standard notation, and explain any problems with it. r.e.b. (talk) 03:04, 27 October 2010 (UTC)

Okay, I'll take angular eccentricity's most recent rv as a knee-jerk reversion! P=)

Even if you think it is inappropriate as the applied symbol, would it be objectionable to at least present the idea of a modification of $\varepsilon \,\!$ as an alternative, even if it is just as a footnote, such as,

----------------------------------------------------------------------------

... the conventional denotation being the Greek letter "alpha", $\alpha \,\!$.

(rest of article)

----------------------------------------------------------------------------

particularly since it has been there as such since the article was created over four years ago (and used elsewhere)? ~Kaimbridge~ (talk) 19:54, 27 October 2010 (UTC)

That still seems inappropriately soapy to me. —David Eppstein (talk) 20:13, 27 October 2010 (UTC)

No, it is objectionable to present the idea, even in a footnote, if it is your unpublished work. If you can publish something—anywhere!—that uses this symbol, and if you manage to meet the notability criterion, then you get to mention it in the article. Until then, no. Not at all. This is policy, and it is not up for discussion. Ozob (talk) 22:58, 27 October 2010 (UTC)

Wikipedia policy WP:NOR, WP:RS does not allow original work or ideas on wikipedia, which I guess includes original symbols, even in footnotes. If you want to mention a modification of epsilon or alpha in an article, you first need to find a widely-used reliable source where this modification is used. r.e.b. (talk) 20:55, 27 October 2010 (UTC)

Shell (mathematics)

I would be glad of some expert eyes on this article. It was prepared yesterday by a new editor Shell0101 (talk · contribs), and tidied up a bit by Icairns (talk · contribs) and was presumably OK or at least not an obvious hoax at that stage. However today two Oxford University IPs have edited further, including introducing a suspicious-looking box saying "She sells sea shells by the sea shore: – J.D.Matsudo, about Y. Yum". Then a third Oxford IP (a) added a hoax tag, (b) blanked the content, and (c) tagged it {{db-a10}} as adding nothing to Kan extension.

I have restored the content and declined the speedy because, though the author started from a copy of "Kan extension", the articles do not now seem to my untutored eye to cover the same ground. However, I have left the "hoax" tag to encourage more eyes. Regards, JohnCD (talk) 21:32, 25 October 2010 (UTC)

Now at AfD here. A stream of Oxford University IPs are removing "hoax" and AfD tags, and maintaining at the AfD that it is genuine but not well presented. JohnCD (talk) 15:13, 26 October 2010 (UTC)

I would like an admin to semi-protect the AfD discussion. The IP users are always polite and pretend to be interested or knowledgeable, but their comments seem designed to keep the charade going. Judging from the WHOIS and reverse DNS information this vandal is an Oxford student. He may be the same as Shell0101 (talk · contribs), who originated the article. These are the IPs who have posted to the AfD discussion:

• 129.67.149.66 (talk · contribs · WHOIS)
• 188.221.247.39 (talk · contribs · WHOIS)
• 111.68.17.214 (talk · contribs · WHOIS)
• 129.67.184.43 (talk · contribs · WHOIS)

Of these, the last also edited the article. Other IPs that edited the article are

• 129.67.148.107 (talk · contribs · WHOIS)
• 129.67.149.66 (talk · contribs · WHOIS)
• 129.67.186.12 (talk · contribs · WHOIS)
• 163.1.180.84 (talk · contribs · WHOIS)
• 163.1.181.49 (talk · contribs · WHOIS)
• 129.67.186.122 (talk · contribs · WHOIS)
• 129.67.148.108 (talk · contribs · WHOIS)
• 129.67.148.107 (talk · contribs · WHOIS)

This is too many to reasonably block, especially since the perpetrator seems to have a new IP every time (he is probably in a computer lab) and since the disruption done by each IP is so small. But given the ongoing difficulty with the AfD discussion I think semi-protection is appropriate. Ozob (talk) 02:49, 27 October 2010 (UTC)

I've now closed the AfD early as delete. We don't need to waste time on these jokers.--Salix (talk): 06:45, 27 October 2010 (UTC)

Trigonometry (wikibooks)

For Wikipedians interested in wikibooks, the wikibooks:Trigonometry book is making some progress. Part 1 is K12 level and there is a part 2 that can take more advanced material. Any help welcome. If this message is off-topic (I'm unsure whether it is or not), please just delete it. JamesCrook (talk) 20:35, 29 October 2010 (UTC)

Bicomplex number & Tessarine

FYI, Tessarine (edit | talk | history | protect | delete | links | watch | logs | views) is requested to be renamed Bicomplex number (edit | talk | history | protect | delete | links | watch | logs | views).

Note that until January, bicomplex number was a separate article, in existence since 2004, when someone redirected it to tessarine, which has existed as a separate article since 2004. If content has been swapped between these articles in the 6 years of each of their existences, then there will be WP:GFDL issues related to the move. 76.66.203.138 (talk) 04:30, 30 October 2010 (UTC)