Wikipedia talk:WikiProject Mathematics/Archive/2023/Dec

Isbell conjugacy, Isbell duality

I think Isbell conjugacy may be an another name or subsection of the (article of) Isbell duality (See also Codensity monad#Relation to Isbell duality). So, I think it might be possible to merge those two articles. Also, if articles are merged, which is better, Isbell conjugacy or Isbell duality ? SilverMatsu (talk) 16:33, 30 November 2023 (UTC)

What is the second article? Isbell duality is a redlink. - CRGreathouse (t | c) 17:21, 30 November 2023 (UTC)

Oops, I overlooked that it was a red link. --SilverMatsu (talk) 17:38, 3 December 2023 (UTC)

I am considering moving Isbell conjugacy to Isbell duality. In that case, Isbell conjugacy is a redirect to Isbell duality. --SilverMatsu (talk) 03:40, 5 December 2023 (UTC)

0#Other fields

Would anyone like to try citing/cleaning up the "Other fields" section of the article on the number 0? Nothing in it looks egregious, but bringing that section up to par and not having a big maintenance banner on a high-visibility article would be nice. XOR'easter (talk) 20:27, 6 December 2023 (UTC)

I at first saw this as "zero sharp other fields". Disappointed. --Trovatore (talk) 20:47, 6 December 2023 (UTC)

Disambiguation of links to Range of a function

Could you help to disambiguate links to Range of a function. The list of articles shown at Disambig fix list for Range of a function include links to the dab page but it is often unclear which article the target should be. Any help appreciated.— Rod ^talk 08:19, 5 December 2023 (UTC)

The correct solution is almost certainly that the very recent deletion of the article at that location be reverted. --JBL (talk) 17:23, 5 December 2023 (UTC)

I reverted the change. It might be better to focus this article a bit on the history of the term 'range', since the concepts are already discussed at codomain and image (mathematics). –jacobolus (t) 17:34, 5 December 2023 (UTC)

Thanks. (My first thought was that I had fixed this a few years ago, but it turns out that what Tea2min and I fixed were links to Domain (mathematics) and Range (mathematics).) --JBL (talk) 18:23, 5 December 2023 (UTC)

@Rodw By the way, thanks for bringing these here instead of just trying to change all of the inbound wikilinks. In most situations where an article with a large number of existing inbound wikilinks is suddenly turned into a disambiguation page, it's at least worth having a conversation before trying to make mass changes, as often in such situations the disambiguation page is a controversial solution not backed by consensus. –jacobolus (t) 00:26, 6 December 2023 (UTC)

@Fgnievinski really wants this to be a disambiguation page. Maybe we can have a fuller discussion here. In my opinion the clearest for readers is to clearly describe at range of a function what the historical usage was of the term 'range'. Codomain and image are closely related concepts which in many contexts end up meaning the same thing, and there was historically a less stringent / less fully developed function concept, and various related terms were used in various looser or less precise (and sometimes a bit contradictory) ways. I think there should be an article (rather than disambiguation page or redirect) about the term "range", so that this can be clearly described. Then readers who encounter this term somewhere in e.g. older literature can look it up and get a clear explanation about it. If we just use "codomain" and "image" articles, I don't think it will be as natural to include that material, and it may either (a) get relegated to a less visible part of one or both articles, (b) be prominently discussed but somewhat distracting to the main point of the article(s), or (c) get skipped altogether or mentioned in passing in a way that doesn't really give readers the clarification they need. –jacobolus (t) 01:59, 6 December 2023 (UTC)

The proper place to discuss an article is the corresponding talk page, as most editors don't follow WikiProjects. Someone else had proposed the DAB at Talk:Range_of_a_function#Disambiguation some time ago; since there was no objection, I've implemented it. I'll repeat my arguments: the present article might mislead a causal reader into thinking there's a third unique concept involved, which is not the case -- "range" is just an ambiguous term for two concepts; furthermore, the fact that page is currently linked from a large number of articles is only one more reason why the incoming links should be retargeted to the unambiguous terms. PS: @Rodw: as you've started this thread, please consider making a note at Talk:Range_of_a_function. Also, the discussion is about a term, not a concept, so MOS:WAW applies; as such, it should be referred to as either "range" or range in the article (after MOS:ITALICTERM and MOS:BOLDREDIR). fgnievinski (talk) 02:11, 6 December 2023 (UTC)

might mislead a causal reader into thinking there's a third unique concept involved – I find this implausible. Much (much, much) more likely is that the disambiguation page or a redirect will leave a casual reader confused about what 'range' is supposed to mean. –jacobolus (t) 02:33, 6 December 2023 (UTC)

+1. --JBL (talk) 17:15, 6 December 2023 (UTC)

You're not going to concede not even about MOS:WAW, that you've reverted? [1] The article is about a term. fgnievinski (talk) 03:23, 7 December 2023 (UTC)

Sorry, my bad there. I was acting sloppily and misinterpreted what the change was (I somehow thought you were reverting back to the disambig page again, I think because I misinterpreted what you meant by the edit summary), and I used an inaccurate edit summary for the revert.

I don't think that the change is particularly helpful though, so I might still revert it with a different edit summary, or at least discuss further. I don't think we want to say "... the term range of a function ..." rather than just "... range of a function ..." in the lead sentence here, partly because the specific term is just range ("of a function" describes the context), and partly because this is inconsistent with other articles on Wikipedia, which may cause (very slight) confusion for readers. In my opinion we do actually want to describe the subject of the "range" of a function at this article and not purely the term per se, even though it's slightly ambiguous/inconsistent in usage.

Maybe there's some other better phrasing we could use in the first sentence. @Chatul, @JBL, @NadVolum, any ideas? –jacobolus (t) 03:40, 7 December 2023 (UTC)

I would change the emphasis rather than the wording: change the range of a function may refer to to the range of a function may refer to. -- Shmuel (Seymour J.) Metz Username:Chatul (talk) 11:04, 7 December 2023 (UTC)

But only a term could "refers to" a concept, so: "the range of a function may refer to" (or "the range of a function may refer to"). Otherwise, if the article were about a concept (which it is not), then WP:REFER should apply. fgnievinski (talk) 03:24, 8 December 2023 (UTC)

Having a discussion at talk:range of a function is also fine, but do note that WT:WPM has ~10x more page watchers, so is substantially more likely to get lively discussion from people who may care about this topic. Many short and relatively obscure wiki pages are of interest to a wider range of editors than those who bothered to explicitly put them on a watchlist. People often assume that an article that seems okay will just continue more-or-less as-is, which is why even dramatic and controversial changes like deleting a longstanding article and replacing it with a disambiguation page can go unnoticed until someone calls it to the attention of a bigger group. –jacobolus (t) 02:39, 6 December 2023 (UTC)

Thanks to everyone for contributions to this discussion. I don't know enough abut the topic to have a view, but I monitor various lists at Wikipedia:Disambiguation pages with links and notice when there are major increases. Often those with large numbers relate to templates used on multile pages and therefore wikiprojects, of people interested in the area, are generally the most helpful places to put requests for help. Not all projects are as active or helpful as this one, so I am really grateful for help.— Rod ^talk 08:00, 6 December 2023 (UTC)

I fully agree with range of a function being an article rather than being disambiguated. Image or codomain should be used instead in most references but if a user does come across range applied to a function then the disambiguation page wouldn't really do the job properly. It isn't like a user will always be able to distinguish easily in selecting the right disambiguation as would be the case if the other use might be range in statistic. The article clearly explains the difference and how in effect the term is now being deprecated because of the confusion. Range in statistics doesn't cause any confusion. NadVolum (talk) 11:20, 6 December 2023 (UTC)

There is a more subtle ambiguity than the obvious one. Some define a function as a set of ordered pairs, with the domain and range being implict; in essence that definition only allows onto (surjective) functions. Others take a categorical approach that includes an explicit domain and range. -- Shmuel (Seymour J.) Metz Username:Chatul (talk) 20:27, 6 December 2023 (UTC)

I tried to add some about how a unique surjective function can be defined given any non-surjective function. Do you want to add some material elaborating about the "implicit" definition of a codomain as image? Is there any good source (e.g. some expository essay somewhere) discussing the subtleties? –jacobolus (t) 23:03, 6 December 2023 (UTC)

Maybe a note that in Algebraic Topology and Homological Algebra the definition with an explicit range is more useful, due to the centrality of exact sequences. Or is that TMI? -- Shmuel (Seymour J.) Metz Username:Chatul (talk) 11:04, 7 December 2023 (UTC)

I have noticed that in logic they tend to use range for what in function theory wold be the image and not bother with codomains. And theorem provers may start off with the natural numbers starting at 1 which surprised me. NadVolum (talk) 12:40, 7 December 2023 (UTC)

The existence of annotated lists and short descriptions is offensive to Wikipedia editors

See this posting. Michael Hardy (talk) 13:36, 10 December 2023 (UTC)

Principle of maximum entropy

I am studying probability and I think the section Overview in Principle of maximum entropy is too high-level: it tells the interdisciplinary applications, but should be an outline of "how it works in practice" intuitively.

I added this new sub-section with what I have understood so far. It was deleted because the "tone" is wrong. Can someone check if the content is wrong? What do I do? Thank you. 62.98.166.30 (talk) 21:54, 9 December 2023 (UTC)

The place to engage in discussion about this is on the associated talk page, in the thread relating to this that has been started at Talk:Principle of maximum entropy § Intuition and examples section. The reverting editor has also tried to explain their thinking on the talk page of the IP address from which you made the edits, at User talk:62.98.166.30 § Comments on recent additions. In short, the editor has made a significant effort to open a discussion with you and to explain the shortcomings, and you should engage there. I tend to concur that the content does not meet Wikipedia's tone requirement: it is more that the addition is 'unsuitable' than that it is 'wrong'. —Quondum 01:06, 10 December 2023 (UTC)

Why don't you create a username to go with your IP address? It would make you more "credible" somehow. PatrickR2 (talk) 07:30, 10 December 2023 (UTC)

It's entirely fine for contributors to Wikipedia to not register a username, see Wikipedia:IP editors are human too. Registering a username can be convenient, allows some additional access privileges such as uploading images, and can make it easier for other Wikipedians to recognize a name, but is not necessary. See also Wikipedia:Why create an account? and Wikipedia:Why not create an account? –jacobolus (t) 07:44, 10 December 2023 (UTC)

Note that you can create an account with any name of your choice. That will not give any indication of your real name, in case you have privacy concerns. PatrickR2 (talk) 07:07, 12 December 2023 (UTC)

The 2nd and 3rd links I posted above discuss this. But anyhow, people have several plausible reasons for wanting to edit Wikipedia under just their IP, many valuable contributors who we want to keep around would prefer to edit that way, and it's not really anyone else's place to second guess that decision or pressure them about it. –jacobolus (t) 07:44, 12 December 2023 (UTC)

"Gabow's algorithm" listed at Redirects for discussion

The redirect Gabow's algorithm has been listed at redirects for discussion to determine whether its use and function meets the redirect guidelines. Readers of this page are welcome to comment on this redirect at Wikipedia:Redirects for discussion/Log/2023 December 12 § Gabow's algorithm until a consensus is reached. Best, ^user:A smart kitten_meow 11:30, 12 December 2023 (UTC)

External (mathematics)

The article External (mathematics), describing a concept in abstract algebra, has been prodded basically for the reason that it is unsourced and appears to be original research. Is it? If not, maybe someone who knows more can rescue it by finding some sources and removing the prod. —David Eppstein (talk) 01:49, 5 December 2023 (UTC)

I would like to add that Internal operation seems to be a redirect to Operation (mathematics), and External operation seems to be a redirect to Binary operation. --SilverMatsu (talk) 04:47, 5 December 2023 (UTC)

And furthermore, the binary operation page that "external binary operation" redirects to has no mention of "external binary operation".

As already explained in Talk:External (mathematics) multiple times since 2011, this is original research and I agree it should be deleted. But I can't find the link to the place where we can support/oppose the deletion. Any idea? PatrickR2 (talk) 00:14, 6 December 2023 (UTC)

You could add a {{prod2}} to the article. Or you could just watchlist it to make sure it gets deleted rather than unprodded and then participate in the inevitable deletion discussion if it doesn't. —David Eppstein (talk) 02:05, 6 December 2023 (UTC)

See Wikipedia:Articles for deletion/External (mathematics). XOR'easter (talk) 20:13, 12 December 2023 (UTC)

Stokes' theorem redirects

In 2021, the article previously titled Kelvin–Stokes theorem was renamed to Stokes' theorem and the one previously at Stokes' theorem to Generalized Stokes theorem, following this move request. As a result of a long-standing bug, EmausBot incorrectly changed all incoming redirects, including those that were typographic variants, to point to Generalized Stokes theorem. I've just reverted the bot's edits, but I have no idea where these should point (or in the case of the last two, whether they should exist, as it seems to be made-up and not a real term):

• Fundamental theorem of exterior calculus
• Gauss Green theorem
• Gauss-Green theorem
• Newton-leibniz-gauss-green-ostrogradsky-stokes-poincaré theorem
• Newton-leibniz-gauss-green-ostrogradsky-stokes-poincare theorem

Would appreciate if someone with knowledge in the matter could look into this. --Paul_012 (talk) 22:53, 12 December 2023 (UTC)

If they aren't coming from concrete inbound links, I'd recommend just deleting the last two, as nobody is ever likely to type those in or link to them. If anyone really wants they could point to generalized Stokes theorem though. I'd send fundamental theorem of exterior calculus to Generalized Stokes theorem. I am guessing Gauss-Green theorem is intended to mean the Divergence theorem, which has sometimes been attributed to Gauss (but I think may have first appeared in some form in the 18th century?). –jacobolus (t) 00:37, 13 December 2023 (UTC)

There's also Stokes' formula, which I just retargeted to Stokes' law, though I'm not sure if it should be disambiguated instead? --Paul_012 (talk) 11:08, 13 December 2023 (UTC)

Good article reassessment for Derivative

Derivative has been nominated for a good article reassessment. If you are interested in the discussion, please participate by adding your comments to the reassessment page. If concerns are not addressed during the review period, the good article status may be removed from the article. ~~ AirshipJungleman29 (talk) 00:38, 14 December 2023 (UTC)

AfC: Conjugate gradient squared method

TechnoSquirrel69 recommended that I should post here to get feedback on Draft:Conjugate gradient squared method. I'm mainly looking for ways to improve the article such that it is more accessible to readers who are unfamiliar with the subject. --MtPenguinMonster (talk) 07:08, 18 December 2023 (UTC)

Thanks for the ping, MtPenguinMonster! For other editors who are at all interested, I provided additional comments at this discussion. —TechnoSquirrel69 (sigh) 07:13, 18 December 2023 (UTC)

Mathematical constant infobox

@Dan Leonard has been adding an infobox to a bunch of articles about various constants, e.g. see the example added to e (mathematical constant) in special:diff/1190499666. I just took one out from imaginary unit.

Are these infoboxes really necessary or helpful? I personally think they are large, distracting, misleading (e.g. requiring a choice of "field" for each constant which can't possibly be complete or even representative), full of low-importance information, and mostly redundant with information that is already is in the article prose. It doesn't seem that important to me that readers are able to find a standardized place for which centuries-old book first mentioned each constant etc. Like all infoboxes, they end up using an awkward space that makes it impossible to nicely format illustrative diagrams or other images in the lead and top section.

Personally I'd just as soon leave infoboxes out of all of these articles, but if we're going to have them can we try to limit how much cruft they accumulate? Golden ratio is an example of an infobox that at least limits itself to different representations of the number (though binary/hexadecimal representations seem irrelevant to all but a vanishingly small proportion of readers, all of whom could easily find that information elsewhere [edit: I tried taking the binary/hex representations out of the infobox, but was reverted).

What do other folks think? –jacobolus (t) 23:12, 18 December 2023 (UTC)

I added a few infoboxes that had been suggested but never implemented in an old discussion here from 2019. The main concerns with the prior (and many of which have since been removed) infoboxes is that they focused too heavily on listing numerical expansions of numbers in various arbitrary bases (see for example {{Infobox number}} and Old revision of Golden ratio) instead of the meaning and significance of the number in mathematics and culture. The infoboxes I added to e, ϖ, and i are in line with this idea. My goals were as follows:

1. Connect the number to fields of mathematics which primarily use it, to guide lay readers especially for constants with more niche applications like ϖ.
2. Enlarge and make prominent the symbol used, for lay readers to ensure they're reading about the right constant. I followed the design of {{Infobox grapheme}} for this as it's a similar concept.
3. Connect the number to the history of mathematics, by giving a "first use" similar to how {{Infobox philosopher}} has a |thesis= option and explaining the name of the constant (if not obvious) with a |named_after= option.

I do agree that this can become too large and might be too much info for an infobox (especially the historical info); however, I do still strongly think having a prominent symbol and decimal expansion is useful the lay reader when encountering most such non-integer numbers in common use. Dan • ✉ 23:39, 18 December 2023 (UTC)

I took the box out of lemniscate constant as well. While the symbol was due to Gauss, I'm fairly certain the constant was known to Fagnano like a century before that, if not earlier, and linking Gauss's diary doesn't seem that useful to readers, compared to just linking to the relevant page or some discussion about it in a footnote somewhere. Mentioning only Gauss in this little section does not provide a complete or particularly accurate historical summary. "Geometry" is definitely not an accurate summary of the "field of application" for this constant (it's more relevant to complex analysis and maybe number theory though frankly an obscure niche topic in any field). Saying the constant is "transcendental" can be done with one word in the prose and really doesn't need a line of an infobox. Putting a giant ϖ symbol doesn't really hurt anything I guess, but it also doesn't seem that meaningfully illustrative. (This does not seem at all the same as the "grapheme" example, where the symbol per se is the subject of the article. Moreover, I find the grapheme infobox to be among the most extreme examples on Wikipedia of gratuitous distraction and wasted space; take a look at the ridiculous box in V.)

Basically, I don't think form boxes are a very good way to describe arbitrary topics, compared to just ordinary English sentences. They work okay for something like a music album or result of a sporting match where there's some well defined collection of data which clearly summarize the topic and which readers are explicitly looking for to compare. But for most general kinds of encyclopedia topics, I think infoboxes (and lead-section nav boxes) are a net negative. –jacobolus (t) 23:53, 18 December 2023 (UTC)

In general I agree. But even when we include infoboxes, a big part of the problem here is that the existence of an infobox with certain parameters encourages unthinking editors to fill in all the parameters. Information should only be included in an infobox if that same information is significant enough to be included in the lead text of an article, because an infobox is part of the lead; see MOS:INFOBOXPURPOSE. —David Eppstein (talk) 01:17, 19 December 2023 (UTC)

I wouldn’t be opposed to infoboxes. Constants are some of the most well-known mathematical concepts that people will come across, and I think infoboxes would benefit the average Wiki reader or lay-person in being able to access some of the basic facts quickly.

I like the current state of Golden ratio with an image and some decimal representations. If I had to add anything, it would be a ‘discovery’ date and perhaps the mathematician responsible but that’s about it.

Slightly unrelated but still on the topic at hand. The current infobox at e has a ‘discovery’ date. Is this really the right word to use? I think something like ‘introduced’ would be better. Sgubaldo (talk) 11:35, 19 December 2023 (UTC)

I strongly dislike this infobox: the image caption is included in the image and cannot be changed; the image caption is written in a old fashioned language that is not understandable by the layman, and even by many students in mathematics (I have changed the short description for saying the same thing in a modern language); the equation $\phi ^{2}-\phi +2=0$ is lacking in the infobox; it is not said that the golden ratio was introduced by ancient Greek mathematicians; the continued fraction is too technical for being listed in the infobox.

In short, I fully agree (on this example, and many others) with Jacobulus concerns. D.Lazard (talk) 12:11, 19 December 2023 (UTC)

Binary, octal and hexadecimal are my bread-and-butter, yet I can think of no rational reason for including any of them in the infobox.

Citing the Latin title of a publication without a translation is not helpful.

Giving a continued fraction for $e$ but not a power series strikes me as bizarre.

Like others here, I don't see the utility of the infoboxes. -- Shmuel (Seymour J.) Metz Username:Chatul (talk) 16:26, 19 December 2023 (UTC)

I agree that the list of approximations in various bases is completely useless. If a single person has ever needed the octal approximation of e and their first stop was a Wikipedia infobox I would be very surprised. This is the original impetus for {{Infobox mathematical constant}} and what I was trying to solve in developing this new infobox style focused on history instead of approximations – the 2019 discussion on this topic heavily criticized the binary/octal/hex lists, yet they still remain on many articles (${\sqrt {2}}$, ${\sqrt {3}}$, ${\sqrt {5}}$, δ_S, $\psi$, etc.) – so I carried forward the old proposal for a new infobox design. I also agree with you on the inclusion of verbose publication titles – that may have been a bit much. I do think that at least a large-size symbol with a prominent decimal approximation may still be of some use (see the example for π at Template:Infobox mathematical constant/doc § Example) but I'm not too beholden to that idea. Dan • ✉ 16:54, 19 December 2023 (UTC)

Yeah, it would be worth removing the binary/etc. representations from all of these articles. If they need to be mentioned at all it can be in some section of reference trivia down near the bottom of an article. –jacobolus (t) 20:18, 19 December 2023 (UTC)

This is one of my peeves, so apologies if you've heard it before. There are many Wikipedia articles that reference this non-mathematical idea of a "mathematical constant" as some sort of "special" number. I think this is an over-generalization from the locution "physical constant", which tends to mean things like the speed of light.

But a mathematical constant doesn't have to be in any way special. All it has to be is constant.

So honestly I would prefer to extirpate this usage from Wikipedia altogether (while still noting the usage if it exists in multiple reliable yada yada yada), but definitely we should not compound the problem with this sort of infobox. --Trovatore (talk) 20:43, 19 December 2023 (UTC)

IMHO, it is reasonable to use the term Mathematical constant for a number whose use in Mathematics is notable. However, I believe that the term key number is unclear and shpould be expanded. -- Shmuel (Seymour J.) Metz Username:Chatul (talk) 14:15, 20 December 2023 (UTC)

I disagree. We should not use "mathematical constant" in this way. --Trovatore (talk) 16:10, 20 December 2023 (UTC)

The problem is that "mathematical constant" is not an invention of Wikipedia, and, per WP:NOR, it is not to Wikipedia to change the common usage. D.Lazard (talk) 19:40, 20 December 2023 (UTC)

It isn't used by mathematicians. It may not be strictly speaking an invention of Wikipedia (I smell Mathworld) but it is not the common usage. --Trovatore (talk) 19:44, 20 December 2023 (UTC)

You're tilting at windmills on this one. The term "mathematical constant", which is more or less a synonym for "interesting number", predates the internet and is widely used in society and academia. –jacobolus (t) 19:50, 20 December 2023 (UTC)

So going back to WP formalities, if there are (non-Mathworld) references at the mathematical constant article that support the claim that a mathematical constant has to be interesting or even "unambiguously defined", it's not obvious which ones they are. What I see are a lot of links that list a bunch of mathematical constants (unarguably so, as they don't change) but do not seem to abstract a notion of "mathematical constant in general". --Trovatore (talk) 20:45, 20 December 2023 (UTC)

Maybe you could start with the two books Mathematical Constants by Finch. Here's the preface of the first. –jacobolus (t) 22:07, 20 December 2023 (UTC)

At a quick scan, the preface talks about things that are true of many mathematical constants, but does not isolate a concept of "mathematical constant" in general; nor does it say anything that needs to be true of all mathematical constants (for example, that they be interesting or even definable). --Trovatore (talk) 22:11, 20 December 2023 (UTC)

I generally agree with jacobolus's concerns and support not using infoboxes in these articles. Adumbrativus (talk) 04:28, 21 December 2023 (UTC)

I think the mathematical constant infoboxes fall into the category described by Wikipedia:Disinfoboxes can be useful: they're disinfoboxes since they mainly just repeat what's already in the article, but they provide a faster way for readers to access key details. I think that what matters most is ensuring that the content of the infoboxes is actually useful information that readers would need to quickly access. The circumstances of a constant's discovery is generally useful to know, whereas its octal representation is less useful, since any reader interested in the octal representation of a number would most likely already know how to convert the number to octal.

--MtPenguinMonster (talk) 11:59, 21 December 2023 (UTC)

As a physicist/materials scientist, I actually like having the boxes as a quick guide if you don't want to read the full article. I would certainly remove the Fields as, for the different examples above, it is 90% wrong and putting in Science everywhere as the Field is accurate but pointless. I would also remove the Type as I don't think it is useful. Ldm1954 (talk) 13:36, 21 December 2023 (UTC)

In my opinion there is not really any detail about these numbers which readers require quick access to. If there were any at all, it would be the first few digits of the decimal expansion, but that should already be written clearly in the first sentence or two, sometimes on its own line, and is not going to be any easier to find or to read if put into a box. circumstances of a constant's discovery is generally useful to know – this is not meaningfully describable in a few words, and trying is generally going to be either useless or wrong. –jacobolus (t) 00:44, 22 December 2023 (UTC)

A big, big disagree about only the first few digits and other information. As with almost any Wikipedia articles, a reader wants a quick summary and will then decide if further research is needed. In my opinion the main "customers" for these constants are not mathematicians. Ldm1954 (talk) 10:09, 22 December 2023 (UTC)

None of the stuff proposed for these boxes (Latin title of some 18th century book or another, name of the mathematician who first mentioned something, whether a number is transcendental or merely algebraic irrational, a large number of decimal digits, digits in binary or hexadecimal, a grossly misleading to the point of wrong list of "applications", etc. is going to help them make a useful decision that wouldn't be better made by reading the first few sentences of the article, and optionally skimming down for whatever other section they are interested in. –jacobolus (t) 18:30, 22 December 2023 (UTC)

So far I think we have reached consensus specifically on the non-decimal approximations: they should be removed in all cases. I think we have also reached consensus that continued fractions should be removed when they are non-periodic, but no consensus in cases where editors feel the fraction has some arbitrary sense of elegance (for instance the golden ratio).

I have accordingly removed infoboxes entirely from Backhouse's constant and Bernstein's constant, non-decimal approximations and continued fractions from Lieb's square ice constant, plastic ratio, Apéry's constant, Euler's constant, e (mathematical constant), and supergolden ratio, and non-decimal approximations only from silver ratio, ${\sqrt {2}}$ (which had duodecimal!), ${\sqrt {3}}$, ${\sqrt {5}}$, ${\sqrt {6}}$ and ${\sqrt {7}}$.

We still have no consensus on whether infoboxes should exist at all for such numbers, and if they were to exist, should they include type (irrational algebraic or transcendental), continued fraction form in some cases, and historical trivia.

I personally still think they should be included only in the case where they have a very common symbol that a layperson would encounter, and should include only the decimal approximation, the type of number, and who or what they were named after (possibly the first user/discoverer if different). I also think "main applications" may have use but am ambivalent on it. Dan • ✉ 00:17, 23 December 2023 (UTC)

If we're going to keep infoboxes at all, I think keeping the continued fractions makes sense for the square roots and e, at least. —David Eppstein (talk) 00:38, 23 December 2023 (UTC)

I'm dubious on "main applications" and the historical trivia. The former can be so broad as to defy listing, and the latter can be too complicated for an infobox. And, as noted above, having fields and advertising them by filling them in on some articles invites thoughtless filling-in across other articles. XOR'easter (talk) 10:17, 23 December 2023 (UTC)

Formatting for synthetic division

I'm new to editing Wikipedia. In LaTeX, I would use an array to show synthetic division, but Wikipedia doesn't seem to work with the \multicolumn and \cline commands needed for it to look right. Horner's method uses plain text to show this formatting, and I would like to fix it. Synthetic division has a different way of displaying it that still has one extra line and doesn't line up quite correctly on the left. I spent a while messing with HTML tables to get this:

3	2	−6	2	−1
		6	0	6
	2	0	2	5

Using this

<table style="text-align: center; vertical-align: middle; border-collapse: collapse;" cellpadding="5">
  <tr>
    <td>{{math|3}}</td>
    <td style="border-left:2px solid;">{{math|2}}</td>
    <td>{{math|−6}}</td>
    <td>{{math|2}}</td>
    <td>{{math|−1}}</td>
  </tr>
  <tr>
    <td></td>
    <td style="border-left:2px solid; border-bottom:2px solid;"></td>
    <td style="border-bottom:2px solid;">{{math|6}}</td>
    <td style="border-bottom:2px solid;">{{math|0}}</td>
    <td style="border-bottom:2px solid;">{{math|6}}</td>
  </tr>
  <tr>
    <td></td>
    <td>{{math|2}}</td>
    <td>{{math|0}}</td>
    <td>{{math|2}}</td>
    <td>{{math|5}}</td>
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which looks okay to me but seems very annoying to deal with. So is it bad practice to put that in the article, and if so what is the preferred way of achieving this? FeatherPurple (talk) 22:37, 24 December 2023 (UTC)

I think synthetic division takes too much space showing multiple step by step how-to examples with distracting colored fonts etc. It would be better to compress these examples down to showing what to write in 1 or 2 chunks instead of the current ~6, with less dramatic coloring if any. I'd probably make them as images rather than HTML tables, as then it's possible to use arrows, circled numbers, precisely placed textual annotations, etc. –jacobolus (t) 02:07, 25 December 2023 (UTC)

Disambiguation of Two-dimensional space

Could you help to disambiguate links to Two-dimensional space? There are a lot of articles (shown in this list which link to the dab page. Not all would fall under this wikiproject but many are either related to Surface (mathematics) or Plane (mathematics) and I don't have the expertise to know which.— Rod ^talk 21:45, 26 November 2023 (UTC)

At a glance, this looks like a merge opportunity? I don't see why surface (mathematics) and surface (topology) shouldn't be a single article, particular when the "mathematics" one is glossed in the disambig page as "a topological space of dimension two". Planes are more specific than 2D spaces and probably should not be in the mix here at all. --Trovatore (talk) 22:42, 26 November 2023 (UTC)

I agree that merging surface (mathematics) and surface (topology) is probably a good idea, but I don't think that planes should be excluded from the disambiguation of 2D spaces. If someone is searching for 2D spaces, they'd probably expect planes to show up as a prominent and canonical example. --MtPenguinMonster (talk) 08:45, 27 November 2023 (UTC)

I don't think these should necessarily be merged. There's plenty to say separately about topological vs. other kinds of features. If we want a merge target for a top-level article about surfaces, it should probably be a merger to surface, which is currently very mediocre. Someone who knows/cares about surfaces in a reasonably wide range of contexts should try to think carefully about how various topics related to surfaces should be be organized into multiple articles, and then split those topics between a few articles with clearly defined scope, which can all be linked from surface as an overview article. –jacobolus (t) 10:47, 27 November 2023 (UTC)

Surface is already an overview article, it reached its current form after a lot of debate with physics and computing editors. It'd be the worst place for merging Surface (topology) -- non-mathematicians are not so excited about topology, sorry. In fact, Surface (geometry) could well be split from Surface (mathematics), as there's a lot to be said about mathematical surfaces to a general audience without mentioning, gosh, "manifolds". Unfortunately, elementary geometry concepts in general don't seem to attract as much attention from math editors at Wikipedia. fgnievinski (talk) 02:52, 6 December 2023 (UTC)

I think this should redirect to Plane (mathematics), which (perhaps along with Euclidean plane or Coordinate plane) is the intended target for the vast majority of inbound links, and which could also discuss general surfaces in a section. @Fgnievinski recently switched from that to a disambiguation page in special:diff/1183701575 without any discussion or consensus, and I think it was a significant mistake. –jacobolus (t) 10:38, 27 November 2023 (UTC)

I reverted to the version which is a redirect. If there is going to be a disambiguation page, it should be under a title like two-dimensional space (disambiguation), with two-dimensional space redirecting to plane (mathematics) which is the commonly intended target. –jacobolus (t) 10:54, 27 November 2023 (UTC)

Surely somebody looking for information on, e.g., ellipsoids, would find a redirect to plane to be perverse. Certainly spheres is a commonly intended target. -- Shmuel (Seymour J.) Metz Username:Chatul (talk) 12:55, 27 November 2023 (UTC)

Why would someone wanting to direct readers to ellipsoids put a wiki-link to two-dimensional space? In my opinion that would be ridiculous, and it seems vanishingly unlikely. –jacobolus (t) 12:59, 27 November 2023 (UTC)

The same question applies to planes; why would someone wanting to direct readers to planes put a wiki-link to two-dimensional space? That seems just as ridiculous and unlikely. -- Shmuel (Seymour J.) Metz Username:Chatul (talk) 14:22, 27 November 2023 (UTC)

In my mind the words "line", "plane", "space" are shorter synonyms for "1-space", "2-space", "3-space" (which originally arose in a context where "space" always meant 3-space).

What do you take 2-space to mean? –jacobolus (t) 18:13, 27 November 2023 (UTC)

I think "plane" by default means Euclidean plane, whereas 2D space definitely does not imply Euclidean, basically ever. I not only don't think "plane" is a reasonable redirect target, I don't even think it should be linked from this target. I think surface (mathematics) and surface (topology) should be merged, and two-dimensional space should redirect to the merged article. Or possibly the merged article should just be named "two-dimensional space". --Trovatore (talk) 18:28, 27 November 2023 (UTC)

I agree with jacobolus. Here are the first few links to two-dimensional space grabbed from https://wiki.riteme.site/wiki/Special:WhatLinksHere/Two-dimensional_space:

• Cartesian coordinate system is about planes
• Real coordinate space is about planes
• Gas electron multiplier maybe shouldn't be linked to any of these articles but if it should then it should be about planes
• many of them (like Piranha 3D, XLfit, Photo psychology, and List of Aqua Teen Hunger Force characters) shouldn't be linked to any mathematical article, but certainly should not be linked to articles about topological surfaces
• Plane of rotation is about planes

Maybe somewhere in Wikipedia someone has linked two-dimensional space when they should have linked something about surfaces, but mostly people are trying to link to something specifically about planes (possibly not in a truly mathematical sense). --JBL (talk) 18:44, 27 November 2023 (UTC)

"Plane" means a wide variety of different things depending on the context, and in my impression is a precise and almost completely interchangeable synonym for "two-dimensional space". For example "hyperbolic plane" = "two-dimensional Riemannian space of constant negative curvature" and "projective plane" = "two-dimensional projective space". Without qualification or context both of these most often mean a Euclidean plane (flat 2-space with a concept of distance), but sometimes mean an affine plane or some other kind of plane. (One slight difference in common use I have observed is that often "two-dimensional space" is used to mean the whole context for the geometry, while "plane" is often used for, more specifically, a "two-dimensional subspace".) –jacobolus (t) 18:57, 27 November 2023 (UTC)

Comment Without any comment on the substance of the matter, I would just like to point out that the intended targets of the links to the page will be heavily biased towards planes simply because that is where the term lead until recently. So anyone who would have wanted to link anywhere else may well have considered linking to Two-dimensional space and then seen that the target is not where they intended to point. Felix QW (talk) 19:49, 27 November 2023 (UTC)

Yes, I think most of these links to "two-dimensional space" just need to be fixed at the link.

Jacobulus points out that "plane" doesn't always mean "flat plane", but I think it does by default, whereas "two-dimensional space" does not mean flat by default.

Maybe stickier, what about $S^{2}$? That's a two-dimensional space, but I think is very unlikely ever to be called a "plane".

I think basically any link to "two-dimensional space" where the reader would be surprised to arrive at an article that includes $S^{2}$ — is just an incorrect link and should be fixed in the text of that article. --Trovatore (talk) 23:57, 27 November 2023 (UTC)

Both of these imply flat when left unqualified. Cases where someone wants a curved space are either called "surface" or e.g. "curved two-dimensional space". But anyway, the 2-sphere is definitely a type of "plane" just like the hyperbolic plane or elliptic plane (historically the sphere was occasionally called the "Riemannian plane" (example 1, example 2), especially when someone wanted to emphasize an intrinsic/axiomatic definition, but that's somewhat ambiguous and now I think usually means something else). It's typically called the "sphere" rather than any kind of "plane" primarily because the concept of a sphere is ~2000 years older than the concept of a "curved plane", but perhaps also because "elliptic plane" is used to mean the sphere with antipodal points identified. Confusingly, the ancient Greek term "line" means any curve and the flat version was explicitly called a "straight line", which is sort of the opposite situation from what we deal with in the 2-dimensional case; in French they picked a better abbreviation and call straight lines "straights" for short. All of these various inconsistencies and ambiguities in nomenclature came about because these names were established long long before they were generalized, and then the generalization was done piecemeal and incoherently by a variety of different authors and translators. –jacobolus (t) 02:47, 28 November 2023 (UTC)

I'm not sure what you mean by "both of these". The phrase "two-dimensional space" absolutely does not imply flat when left unqualified. --Trovatore (talk) 07:16, 28 November 2023 (UTC)

Yesterday I spent 20 minutes skimming through academic papers matching the search result "two-dimensional space", and when unqualified this is usually referring to the Euclidean plane. Examples include children learning about maps, computer algorithms for segmenting images, wallaper groups, modeling car traffic, surfaces projected onto their tangent space, fractals, graph algorithms for graphs embedded in the plane, imaging of thin slices of some three-dimensional material, etc. There are also lots of papers talking about "curved two-dimensional space", "two-dimensional space-time", "non-Euclidean two-dimensional space", etc., but even these are not too often used for just any old surface from what I can see. Examples where there is an arbitrary surface include e.g. robot kinematics where there's some "two-dimensional space" of available motion for some part, and computer graphics mapping an image parametrically onto a triangle mesh; these are examples of real coordinate space. –jacobolus (t) 15:13, 28 November 2023 (UTC)

I'm really having trouble seeing why you would ever not want to just say "plane" if you mean a flat 2D space. "Plane" very clearly says it's flat (a plane is a tool used to make things flat). "Two-dimensional", on the other hand, says nothing whatsoever about flatness, just about the number of independent ways you can move in the space. --Trovatore (talk) 17:15, 28 November 2023 (UTC)

What this demonstrates is that you've absorbed a particular expert perspective so far as to lose sight of how non-experts use words and language, rather than anything about the encyclopedia. The usage of "two-dimensional" to mean "planar" is common, widespread, and rarely causes confusion. (By contrast, the usage of "two-dimesional" to describe a curved surface embedded in three-space causes lots of confusion.) --JBL (talk) 17:46, 28 November 2023 (UTC)

I'm not trying to psychoanalyze anyone; I'm just telling you that in practice "plane" and "two-dimensional space" are typically treated as synonyms. But as I suggested below, I think we could make an article at two-dimensional space. The tricky part then is figuring out how to organize (and ideally expand) material between there, plane (mathematics), Euclidean plane, inversive plane, hyperbolic plane, sphere, affine plane, projective plane, coordinate plane, surface, surface (mathematics), surface (topology), etc., most of which are currently mediocre. The part I think is a bad idea is encouraging meat-bots to go "fix" every wikilink pointed at two-dimensional space so they don't land on a disambiguation page, which is apparently banned. –jacobolus (t) 17:47, 28 November 2023 (UTC)

Maybe it's useful to consider a different approach to the problem: under what circumstances would someone put a link to two-dimensional space? Are there scenarios where someone would be more likely to link to two-dimensional space than to an article like plane or surface? --MtPenguinMonster (talk) 09:08, 28 November 2023 (UTC)

One other possibility would be to make a short halfway-to-disambiguation page modeled on one-dimensional space. –jacobolus (t) 19:11, 27 November 2023 (UTC)

The only thing certain after this lengthy debate is "Two-dimensional space" is an ambiguous term. It's only natural, then, to make it a disambiguation page. It could be marked with {{bca}} if there's hope to write something unique about it. But please avoid duplicating Plane (mathematics) and Surface (mathematics) (or Surface (topology)). fgnievinski (talk) 03:13, 6 December 2023 (UTC)

No it should absolutely not be a disambiguation page. –jacobolus (t) 03:36, 6 December 2023 (UTC)

We should abide by the WP:DAB policy -- there's no WP:PRIMARYTOPIC, hence the dab page. BTW: your reasoning is inconsistency with the explanation in Dimension, esp. the analogy with degrees of freedom. fgnievinski (talk) 03:41, 6 December 2023 (UTC)

(Note: I've formalized this redirect discussion at Wikipedia:Redirects_for_discussion/Log/2023_December_6#Two-dimensional_space. fgnievinski (talk) 03:46, 6 December 2023 (UTC))

We should abide by the fundamental and abiding policies of "do what's best for readers" and "do what makes the best encyclopedia". But since you really seem to like WP:THISANDTHAT abbreviations, take a look at WP:CONCEPTDAB.

your reasoning is inconsistent – you are going to have to elaborate. I don't understand what you are getting at. –jacobolus (t) 03:43, 6 December 2023 (UTC)

If you'd like to write a "short halfway-to-disambiguation page modeled on one-dimensional space" that's fine. I'm curious what could be said about two-dimensional space beyond what's already stated in Plane or Surface. But since that broad-concept article (BCA) doesn't exist yet, I had proposed to mark Two-dimensional space (disambiguation) with the {{bca}} template. That can be done whether or not Two-dimensional space redirects to the DAB page or to an existing article.

I claim there's an inconsistency in holding "in practice 'plane' and 'two-dimensional space' are typically treated as synonyms" then explaining Dimension as "the number of degrees of freedom of a point that moves". If Wikipedia defines two-dimensional space as not necessarily flat, then it should redirect consistently, hence to Surface (mathematics).

If you insist on the typical notion, 2D=planar, then Two-dimensional space should redirect to Euclidean plane, the one most closely corresponding to the physical, geometrical or everyday notion. This is analogous to Three-dimensional space and Euclidean 3-space already being covered in the same article.

Finally, since everyone here seems to have a different opinion, the DAB page would be a compromise solution. At least until a BCA emerges. fgnievinski (talk) 04:35, 7 December 2023 (UTC)

No, a disambiguation page is not a compromise; a disambiguation page is a significant disruption that forces a broad swath of other pages to immediately change, because a different [in my opinion misguided/too rigidly applied] policy holds that wiki-links can't point at disambiguation pages, and there are scripts for hunting such links and editors who feel an urgent need to go "fix" them right away causing a wave of unnecessary edits. (This policy is helpful in the typical case, e.g. an inbound link to Amazon should almost certainly be either the mythical tribe, the river, or the company, and pointing at a disambiguation page is going to be confusing to readers.) A quick fix is a redirect + hatnote, and a higher-effort solution is some "broad concept article".

Even though Euclidean plane was originally titled two-dimensional space, then later moved (by you) to Two-dimensional Euclidean space, and finally moved (by me) to Euclidean plane, and even though the most common meaning of "two-dimensional space" in the literature is the Euclidean plane, I don't think two-dimensional space should be a redirect to Euclidean plane, because the term itself is much broader / less specified, and does not (per se) imply the Euclidean plane. References in physics literature to "two-dimensional space" with constant curvature (sphere or hyperbolic plane) are pretty common. Other references to "two-dimensional space" mean the affine plane or the real coordinate space of 2 dimensions.

In my opinion all of the articles related to planes and surfaces (plane (mathematics), Euclidean plane, inversive plane, hyperbolic plane, sphere, affine plane, projective plane, coordinate plane, complex plane, surface, surface (mathematics), surface (topology), etc., with the notable exception of differential geometry of surfaces) are mediocre, substantially incomplete, and somewhat neglected, and would benefit from significant additional work searching for sources, synthesizing them, writing clear explanations, drawing attractive figures, etc. (If anyone wants to make a bigger collaboration about this, it would be a good general project.) –jacobolus (t) 05:28, 7 December 2023 (UTC)

Indeed there is a lot to be improved. On the topic of two-dimensional spaces: where do we cover general two-dimensional vector spaces? While they are of course isomorphic to the Euclidean plane, some natural examples like the solution set of a second order homogeneous linear ODE do not look like a plane to the learner. —Kusma (talk) 06:48, 7 December 2023 (UTC)

I think "space" doesn't usually mean "vector space", unless there's been specific context established. I'm skeptical that there should be a whole article about two-dimensional vector spaces, but I guess it's not completely outlandish. But even if there were such an article, I don't think it would be in contention for the (or even a) primary meaning of "two-dimensional space". --Trovatore (talk) 17:44, 7 December 2023 (UTC)

That "space" has mathematical meanings beyond vector spaces is a relatively advanced concept. "Two-dimensional" is also a fairly advanced concept when you are not talking about vector spaces. —Kusma (talk) 20:03, 7 December 2023 (UTC)

So saying that a surface is two-dimensional is "a fairly advanced concept"? That is absurd. —Quondum 16:40, 8 December 2023 (UTC)

Actually I think "space" with the meaning of "vector space" is (in addition to being uncommon, except with context firmly established) arguably a "fairly advanced concept". At least I found it difficult to get low-level students to understand abstract vector spaces, mainly because of the "abstract" part. This was always a little disappointing to me, because the material itself was so easy, really much easier than the calculus they'd already done — but it was just the first time they'd ever really had to deal with the notion of an abstract structure. The word "space" naturally invites geometric/topological intuitions, not abstract algebraic ones. --Trovatore (talk) 20:42, 13 December 2023 (UTC)

@Fgnievinski I started writing a (currently barely beyond stub level) draft article at user:jacobolus/2d. Even this one so far is better than a disambiguation page though, in my opinion. –jacobolus (t) 04:38, 8 December 2023 (UTC)

Thank you, that's pretty readable. Would it be possible to say something about the difference (or lack thereof) between plane and surface in non-Euclidean spaces? You alluded to above the usage sometimes is mostly historical. Or just sidestep the issue and say planes and surfaces are two-dimensional flat spaces and curved spaces, respectively? fgnievinski (talk) 06:08, 8 December 2023 (UTC)

I wonder if there's a good source about this. According to Wiktionary, the English words 'plane' and 'surface' come from Latin originally for 'flat' and 'top surface' (like a tabletop maybe?) respectively. I'm not exactly sure what the various relevant Ancient Greek words were.

In any event, in mathematics my impression is that the concept of a "plane" originally meant a flat (infinitely extensible?) surface, while a "surface" meant the boundary of some solid shape. (In English translations of Euclid's Elements, the definitions are that "a a surface is that which has length and breadth only", while "a plane surface is a surface which lies evenly with the straight lines on itself", analogous to the distinction between "line" and "straight line". Later things called "planes" were drawing on some analogy with the Euclidean plane, while later things called "surfaces" were drawing on some analogy with an arbitrary boundary of a solid shape, but from one to another it wasn't always the same analogy. I'm not sure there's really an entirely clean separation that can be made between them. But it's possible there are some sources that have tried. –jacobolus (t) 08:14, 8 December 2023 (UTC)

A good start, but

1. I don't believe that it is appropriate to mention planes in the first sentence, since not all 2-surfaces are planes.
2. The reference to parallel lines is confusing. The discussion should take into account that only on a flat space is a curve at a fixed distance from a given line guarantied to be a straight line. Also, on the hyperbolic plane the literature refers to lines as parallel that are not at a fixed distance from each other.
3. It wouldbe helpful to mention that some, but not all, surfaces are the boundaries of solids.
4. A double torus (sphere with two handles) is a simple example of a surface that is not a plane, and a mobious strip is a simple example of a surface that is not the boundary of a solid.

Is it TMI to mention that the use of coordinates might require multiple coordinate patches (charts)? -- Shmuel (Seymour J.) Metz Username:Chatul (talk) 18:21, 8 December 2023 (UTC)

The reason to mention planes at the start is that "two-dimensional space" as used in academic literature (which appears most plentifully in other applications rather than pure mathematics papers) most commonly means some kind of plane.

I think some kind of explanations about parallel lines is the clearest / most historically important / most common way of describing the difference between the sphere/plane/hyperbolic plane (vs. e.g. observations about the circumference vs. diameter of circles or the sum of internal angles of a triangle), but you're probably right there's some better phrasing. Maybe someone has seen a source with a good brief summary? It's hard to condense into 1–2 sentences.

It would be helpful to mention that some, but not all, surfaces are the boundaries of solids. This could certainly be mentioned, though I'd maybe put it in a later section. How often are the boundaries of arbitrary solids ever called "two-dimensional space"?

Is it TMI to mention that the use of coordinates might require multiple coordinate patches (charts)? To be honest I'd conceptually really rather say that a 2-dimensional space has points with two degrees of freedom (our current article there is a stub) or that a point can slide in two independent directions, rather than saying that points in 2-dimensional space can be represented by two coordinates; I just couldn't find a way to write that which was concise enough while being very legible/accessible.

There's obviously a great (great) deal that could be said here. For instance, a new section could be added unpacking each sentence or two of what I wrote so far. My main goal with this initial draft was to effectively disambiguate this article title so someone arriving there from a wikilink or search can find the more specific page they're looking for, which I don't think a traditional bullet list disambiguation page really accomplishes. –jacobolus (t) 18:51, 8 December 2023 (UTC)

I think Jacobolus and I have found some common ground. The best intuitive description is that "a point can slide in two independent directions (but not three)". Formalizing exactly what that means gets pretty technical, but the intuition is both accessible and correct. That should be the first thing we say about two-dimensional spaces. --Trovatore (talk) 22:35, 13 December 2023 (UTC)

Should I move my current draft to two-dimensional space, and you can work on it there, or do you want to take a crack at writing something independently? –jacobolus (t) 01:08, 14 December 2023 (UTC)

Are you ready for others to make edits? I'd like to change the second sentence to The most common two-dimensional spaces are often called planes or more generally surfaces. and change the end of the third paragraph to have a footnote: are called Riemannian surfaces. — Preceding unsigned comment added by Chatul (talk • contribs) 14:40, 18 December 2023 (UTC)

@Chatul, have at it: Two-dimensional space. –jacobolus (t) 14:53, 18 December 2023 (UTC)

The redirect of Two-dimensional space to Plane (mathematics) just seems awfully wrong to me. I think it should become the disambiguation page rather than having Two-dimensional space (disambiguation) as well. I agree 2D or even 2D space mostly means a plane - but two-dimensional space only includes the plane as one of many instances. 2D implies a specific instance, spelling it out means the general type of space. NadVolum (talk) 13:13, 7 December 2023 (UTC)

I also had a look at Google and it was not at all obvious to me what was the usual use of 'two-dimensional space'. The usual one of a space with two parameters seemed very common. The flat meaning of plane was not as common as implied above, the main place I saw it meaning a pane was in vectors and matrices where a subspace was mostly referred to instead. NadVolum (talk) 13:25, 7 December 2023 (UTC)

Notes

Disambiguation of other terms

Thanks for all the edits, reverts and discussion on this, with lots of useful ways forward. If anyone had any good ideas about links to the dab page Parametrization (shown at Disambig fix list for Parametrization that would be great as well.— Rod ^talk 15:31, 28 November 2023 (UTC)

And links to Tensor category (shown here) are also giving me grief trying to disambiguate them.— Rod ^talk 16:19, 28 November 2023 (UTC)

Update

We've made a start of a "broad concept article" at two-dimensional space, which is currently mainly a kind of prose disambiguation page, trying to direct readers to the appropriate more specific kind of space they might be looking for, or to more general articles about mathematical space etc. If anyone feels ambitious, feel free to add subsequent sections covering various 2-dimensional spaces in more specific detail, or to add more kinds of 2-dimensional spaces that we missed so far. –jacobolus (t) 21:29, 26 December 2023 (UTC)

RfC Sum and Difference of Powers

The page Draft:Sum and Difference of Powers has been sitting for a while. Perhaps people in this project should comment on whether it is worth having this page, and if it is accept it. Ldm1954 (talk) 16:21, 18 December 2023 (UTC)

This draft is a WP:REDUNDANTFORK from Factorization#Recognizable patterns. As this title may be useful, I have just created a redirect from Sum and difference of powers to Factorization#Recognizable patterns. Thus, this draft can be deleted. D.Lazard (talk) 17:10, 18 December 2023 (UTC)

I will wait a day or so to hear more. If not I will delete it. Ldm1954 (talk) 17:17, 18 December 2023 (UTC)

I wouldn't mind someone making a separate article about this if they had more to say about it that seemed out of scope for the existing section, e.g. mentioning particular applications, talking about the history, etc. The draft currently doesn't seem to add too much beyond what is already in the section, and could be deleted or merged. We may want to add a list item to sums of powers. –jacobolus (t) 17:26, 18 December 2023 (UTC)

I think this article may have potential. It's too early to decide to delete it. I have changed the title to Factorization of sums and differences of powers, since factorization is what it's about, and since it clearly shouldn't have so many capital letters. I also did a lot of copy-editing. Much of the TeX code seemed to have been written by one of those dumb robots that install huge numbers of superfluous {{{{{curly braces}}}}} and there were other problems with it. (There were several occurrences of the "align" environment with no alignment tabs but with alignment achieved by multiple instances of text made invisible by coloring it white. Can you get more crude than that?) Michael Hardy (talk) 00:11, 27 December 2023 (UTC)

Reviving WP:3TOPE

Is there any chance to revive this inactive project, WP:3TOPE??? Also, I am puzzled that this project focuses on the polyhedron, but there is some discussion that talks about the improvement of polygons and polytopes as well. In that case, is there any way to rename this project? Dedhert.Jr (talk) 10:58, 28 December 2023 (UTC)

Coin rotation paradox

I'm not sure what I should think about the Coin rotation paradox. First I thought it's a big made up story out of something small because there was this mistake in some SAT test. So I started a deletion discussion which now has a majority for keep. Maybe this event is relevant but still this doesn't seem to be a scientifical term for me - there aren't even equivalents in other languages. The discussion about perpective seems interesting though. But where does it start and where does it end? Does it make sense to bringt a 3rd dimention into a 2-dimentional test? Is it a good explanation for a sidereal year? From the perspective of breeding 1+1 can be 3, but would this be a correct answer in a maths test? (Guess there might be better examplex than that). What do you think about this? - Flexman (talk) 11:59, 28 December 2023 (UTC)

Even if it were only about a mistake on the SAT, it could in principle be notable if multiple reliable sources had written in sufficient depth about it. As it happens, it is a well-known geometrical curiosity with a life beyond the SAT. XOR'easter (talk) 03:46, 30 December 2023 (UTC)

Why did you want to delete this? It seems like a nice explanation of an interesting and meaningful geometry problem. In my opinion this is the kind of topic Wikipedia does best at. –jacobolus (t) 05:37, 30 December 2023 (UTC)

See also Epitrochoid, Hypotrochoid, Epicycloid, Spirograph, Tusi couple, Epicyclic gearing, etc. –jacobolus (t) 05:49, 30 December 2023 (UTC)

Good article reassessment for E (mathematical constant)

E (mathematical constant) has been nominated for a good article reassessment. If you are interested in the discussion, please participate by adding your comments to the reassessment page. If concerns are not addressed during the review period, the good article status may be removed from the article. ~~ AirshipJungleman29 (talk) 19:16, 30 December 2023 (UTC)