Wikipedia talk:WikiProject Mathematics/Archive/2018/Nov

Draft:Modos is now in mainspace

I have moved the draft in the tittle to Modos. I don't have an expertise to properly review it (i.e., can't make sense of it) and thus it can benefit from the attentions from the other editors. Regards. -- Taku (talk) 23:29, 4 November 2018 (UTC)

And now PRODded. –Deacon Vorbis (carbon • videos) 23:55, 4 November 2018 (UTC)

PROD declined; that was fast. Now at AfD. –Deacon Vorbis (carbon • videos) 00:10, 5 November 2018 (UTC)

Draft:Near Square Primes

I came across this in the WP:AFC queue. I'm not sure if this subject qualifies for inclusion. If a member of the project could let me know, that would be great. (Please ping me as I'm not watching this page). --K.e.coffman (talk) 00:52, 10 November 2018 (UTC)

To editor K.e.coffman: The topic deserves to be in the main space, but is already present at Landau's problems#Near-square primes. As this article section and the draft have essentially the same content, and both articles are very short, I suggest to merge the draft into Landau's problems, and to create a redirect Near-square primes linking to this article section. D.Lazard (talk) 09:25, 10 November 2018 (UTC)

Content merged, redirect created. XOR'easter (talk) 13:46, 10 November 2018 (UTC)

Featured quality source review RFC

Editors in this WikiProject may be interested in the featured quality source review RFC that has been ongoing. It would change the featured article candidate process (FAC) so that source reviews would need to occur prior to any other reviews for FAC. Your comments are appreciated. --Izno (talk) 21:31, 11 November 2018 (UTC)

Duodecimal

Discussions regarding some unusual editing occurred at X, E, duodecimal (and in several other places on that page). Does any information at User:Xayahrainie43/duodecimal have an encyclopedic purpose? Please offer opinions at the deletion discussion. Johnuniq (talk) 04:39, 16 November 2018 (UTC)

Math extension at wishlist survey

A wishlist item may interest people here: meta:Community Wishlist Survey 2019/Reading#Functional and beautiful math for everyone. Johnuniq (talk) 06:56, 20 November 2018 (UTC)

Paul Erdős

A question both deep and profound,
Is whether a circle is round:
In a paper by Erdős,
Published in Kurdish,
A counter-example is found.

Author unknown (not me, although I could hazard a guess). I'll be back later with more mathematics-related links to DAB pages which require expert attention, I'm collecting another new bunch. Narky Blert (talk) 22:19, 23 October 2018 (UTC)

Cute. Except it doesn't actually rhyme. But oh well. --Trovatore (talk) 22:29, 23 October 2018 (UTC)

There are two different versions of this in

• Singmaster, David; Souppouris, D. J. (1978), "A constrained isoperimetric problem", Mathematical Proceedings of the Cambridge Philosophical Society, 83 (1): 73–82, doi:10.1017/S030500410005430X, MR 0470577
• Alexanderson, G. L. (September 1981), "An Interview with Paul Erdős", The Two-Year College Mathematics Journal, 12 (4): 249, doi:10.2307/3027072

I have no idea whether either of them is the original source. There's another mathematical limerick attributed to John Milnor here. —David Eppstein (talk) 23:02, 23 October 2018 (UTC)

I read the limerick in a book I can't recall (I suspect it was by Ronald Graham but I don't see anything likely). At any rate, the author used the limerick to show how "Erdős" should be pronounced—Erdős rhymes with Kurdish. Johnuniq (talk) 02:33, 24 October 2018 (UTC)

No, it doesn't rhyme with Kurdish. The second syllable is OK, but it's unstressed. In that case, the first syllable should rhyme too, and it doesn't. --Trovatore (talk) 03:22, 24 October 2018 (UTC)

Well, better than it rhymes with overdose or acuerdos, anyway. —David Eppstein (talk) 02:36, 24 October 2018 (UTC)

It might rhyme with lairdish, if there is such a word. --Trovatore (talk) 03:56, 24 October 2018 (UTC)

How about But a brief note by Erdős/Writ on a spare dish? Nah, you're right, probably not. But at least it rhymes. --Trovatore (talk) 05:23, 24 October 2018 (UTC)

It wouldn't have occurred to me that anyone would think "Erdős" rhymes with "Kurdish" if I hadn't seen this. I pronounce the "Er" in "Erdős" like "air", rhyming with "chair" and the "ur" in "Kurdish" like the "r" in "ring", and the vowel in the second syllable of "Erdős" like the German "ö", and I make the second syllable of "Erdős" rhyme with "fish". I have no idea what degree of correctness there may be in my pronunciation of the second syllable of "Erdős". Maybe approximate rhymes work better when you hear them that when you read them (maybe except the ones that are standard and expected). Michael Hardy (talk) 18:05, 25 October 2018 (UTC)

So now I tried Google Translate and it agreed with my pronunciation of "Erdős". Michael Hardy (talk) 18:12, 25 October 2018 (UTC)

Just as a voice from the Hungarian neighbourhood: I believe the vowel in the second syllable of "Erdős" sounds in Hungary like the vowel part in the first syllable of "Gershwin" I just noticed you could also curse Purgy for the same vowels (cutting off beginning at the r-part) in America, or, better, the first part of the merging of "deux" and "chevaux" in France (cutting off after the sh-sound; 2CV(apeur) is a famous vintage car there). Purgy (talk) 18:59, 25 October 2018 (UTC)

Yeah, there aren't going to be any perfect rhymes in English, probably. But English has a tendency to treat vowels in unstressed syllables less distinctively than the ones in stressed syllables, so the -ish part doesn't have to be perfect to sound like a rhyme. --Trovatore (talk) 19:32, 25 October 2018 (UTC)

The approximate rhyme between "-dős" and "-dish" seems similar to the sort used by German poets. In the Ode to Joy, Friedrich Schiller wrote:

Deine Zauber binden wieder
Was die Mode streng geteilt;
Alle Menschen werden Brüder
Wo dein sanfter Flügel weilt.

Michael Hardy (talk) 18:05, 26 October 2018 (UTC)

Last comment on rhyming: Ach n"eige", Du schmerzensr"eiche", Dein Antlitz gnäd"ig" meiner Not ... Gretchen's prayer, noticing to be pregnant; in Faust, J.W.v.Goethe. The quoted parts are taken to rhyme, because the sounds belonging in German to "ei" and "i" are quite neighbored, as are the pronunciations of "g" and "ch" in several regional dialects. I could not call into my awareness any word from the English language that ends in a sound, reminding me directly of how "Erdős" does. Thank you! Purgy (talk) 15:02, 27 October 2018 (UTC)

I was aware that Erdős and Kurdish aren't true rhymes; but, hey! it's a limerick, and anything goes.

As for part-rhymes in English, here are a few examples from Byron's Don Juan: laureate, Tory at, ye at; good, food, hood; try, posterity; tongues, wrongs, songs; arise, prophecies, eyes; more, hoar, poor; miscreant, pant, want; vile, smile, toil – and that's just from the first 13 stanzas of a book-length poem. Narky Blert (talk) 10:10, 8 November 2018 (UTC)

I think "try" and "posterity" might have rhymed perfectly in Shakespeare's time, as might some of the others. Michael Hardy (talk) 21:43, 21 November 2018 (UTC)

Symmetry

Anyone want to participate in a silly discussion about symmetry? At Fountain (Duchamp), a long-term editor of that article is edit-warring to include sourced material claiming that the piece was rotated 90 degrees around "its axis of symmetry" from its normal position, despite the clear evidence of a photo showing that it has no axis of symmetry and that the change from its normal position is a 180 degree rotation. See also Talk:Fountain (Duchamp)#HOW many degrees?. —David Eppstein (talk) 23:41, 22 November 2018 (UTC)

I feel like we should either go all out and write the spatial transformation in terms of quaternions, or we should say the guy laid it on its back so the surface facing the viewer is the one that normally collects piss. XOR'easter (talk) 01:22, 23 November 2018 (UTC)

Class (set theory)

Hi. I've been going through some set theory books lately. I have the habit of going through Wikipedia articles about specific topics in things I'm reading in order to chase some references or get just a bit more of information. So I saw the class article is deficient in some aspects (feels more like my own class notes than an encyclopedic, referenced entry). Since I don't want to come and mess up and then have someone revert my good faith first edits, I want to ask some clarification:

• Are books such as Pinter's A Book of Set Theory (ISBN 978-0486497082) or Suppes's Axiomatic Set Theory (ISBN 978-0486616308) or Smullyan's and Fitting's Set Theory and the Continuum Problem (ISBN 978-0486474847) acceptable as citations? As in: can I take these books, first published by reputable companies, as proper sources? There are a few things I've already come across that could clarify, expand, or improve things in the class article, including some things talked about in the talk page.
• Some people in the talk page have already mentioned how some definitions or explanations or implications of some aspects of what a class is kind of 'depend on' what theory one takes as a basis, or which context. How does one proceed from here? Do you write something akin to "according to Reputable Author in A Book About the Subject, a class is X in Y"? (with the proper reference).
• How and when is it acceptable to completely rewrite an article, or to propose it? The article does not exactly follow the recommended guidelines for math articles: after the lead (already problematic and without a single in-line or in-text citation), there's just a section with a handful of 'examples,' and then by the end there's a more formal definition in set-theoretic terms.

Broadly, these are my concerns about editing. These concerns reflect the ways in which I believe I can improve this article. The reason I'm asking here instead of the talk page for the article is that I feel more people watch this than that other one. Thanks a lot to whoever reads and responds. --Paper wobbling sound (talk) 01:35, 23 November 2018 (UTC)

In this area, I think it's better to group different variations by the general theory that they follow (as our existing article does in its "Classes in formal set theories" section, rather than by which book you read it in. That said, those books all sound reliable enough as general-purpose sources on set theory to me, as long as you're careful to determine which brand of set theory they follow. For specific issues involving the treatment of classes in specific theories, more specialized monographs might be appropriate. —David Eppstein (talk) 04:40, 23 November 2018 (UTC)

"How many degrees?" they ask...

at Talk:Fountain (Duchamp)#HOW many degrees?. Editors here may like to lurk, as I've been doing, or jump into the fray, on what has turned into one of the most interesting WP:MINUTIA discussions I've seen (the wrong word, as my reference isn't to Chionanthus but to very tiny points being discussed at length - I just don't know how to spell it). My obvious reason for alerting those here is not to facilitate any kind of resolution (which seems to have been partly met with a new edit on the page which doesn't answer, but wordsmithily sidetracks, the question: "How many degrees?") but is solely because I am enjoying the spectacle of it and want the discussion to continue. Randy Kryn (talk) 20:59, 23 November 2018 (UTC)

See "Symmetry" section, above. —David Eppstein (talk) 21:55, 23 November 2018 (UTC)

Thank you, that's a great addition to the topic. Randy Kryn (talk) 22:09, 23 November 2018 (UTC)

The semi-resolution referred to above has just been reverted. Randy Kryn (talk) 22:05, 23 November 2018 (UTC)

I'm keeping out of the formal discussion for lurking purposes, but wouldn't the answer be that it was first rotated 180 degrees and then stood up 90 degrees? Randy Kryn (talk) 22:15, 23 November 2018 (UTC)

That is a valid solution. There are even published sources that give that solution. It's more complicated than the single-rotation solution, though. And which 180-degree rotation: the one where you spin it on its base or the one where you turn it upside down while keeping it facing you (both work)? —David Eppstein (talk) 23:05, 23 November 2018 (UTC)

Maybe the artwork is just the way it was facing when Duchamp (or whoever) first saw and bought it. So it was never rotated at all, just seen, bought, signed, and displayed, making the question, in that scenario, moot. Saying on the page that it was rotated at all could be speculation. Randy Kryn (talk) 23:14, 23 November 2018 (UTC)

I like the idea of some long-forgotten warehouse worker leaving it on its back because it looked like it would tip over. I was also a bit charmed by the very scholarly book that gave a description which just can't be right, and then provided a metaphorical reading for it... which a different choice of axis would make true! XOR'easter (talk) 01:16, 24 November 2018 (UTC)

Wishlist

m:Community Wishlist Survey 2019/Reading/Functional and beautiful math for everyone and m:Community Wishlist Survey 2019/Editing/Make the math tag support non-Latin languages appear to be the only math-related proposals on the Community Wishlist. Voting (straight up approval voting; editors can support as many or as few wishes as they want) ends in about four days. WhatamIdoing (talk) 18:19, 26 November 2018 (UTC)

Division by infinity

A new student editor created Division by infinity, which could I think be a good counterpart to our existing page Division by zero, but it just wasn't ready yet (WP:OR-ful, WP:ESSAY-ish, etc.). I have therefore moved it into Draft space. This seemed a less hostile approach than dumping them into AfD, which seemed a likely eventuality otherwise. (I wouldn't have moved it unilaterally if anyone else had edited it other than its creator.) XOR'easter (talk) 16:52, 30 November 2018 (UTC)

FYI, I just WP:R2 tagged the leftover redirect per Wikipedia:Drafts#Tools for moving articles to draft space. –Deacon Vorbis (carbon • videos) 17:35, 30 November 2018 (UTC)