Wikipedia talk:WikiProject Mathematics

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Emmy Noether FA review

It would be much appreciated if people could read the Emmy Noether article and check for statements that are unclear, under-cited, or otherwise unbecoming the encyclopedia project. XOR'easter (talk) 22:06, 12 October 2024 (UTC)

For those more knowledgeable with the subject matter than I am, the two sections that may need some more citations the most are the ones on ascending and descending chain conditions and algebraic invariant theory. Sgubaldo (talk) 23:29, 12 October 2024 (UTC)

My impression from working on the article previously was that everything discussed in it is addressed in the references already present (and for a math topic, having a clickly blue linky number for each sentence doesn't necessarily go further to satisfying WP:V than having one per subsection). But this would be a good opportunity to point readers at references that are particularly good. Anybody have favorite books about either of those? XOR'easter (talk) 18:30, 13 October 2024 (UTC)

The section on algebraic invariant theory doesn't make enough contact with Noether's work in the area, which was eclipsed by that of Hilbert. Both the Rowe and Dick source describe her dissertation done under Gordan, which was devoted to symbolic computation of invariants, and in fact a later source of some embarrassment. The section would benefit by emphasizing this, and summarizing the sources better (and referring to them). Tito Omburo (talk) 19:33, 13 October 2024 (UTC)

Care to tackle that? I could try, but I'm not sure when I'll have an uninterrupted block of time long enough. XOR'easter (talk) 21:00, 13 October 2024 (UTC)

@Sgubaldo, @Tito Omburo, @XOR'easter. The discussion now is into FARC: one delist and one keep. I have found some of the unsourced sections after looking up at its content. Dedhert.Jr (talk) 11:55, 29 October 2024 (UTC)

As an update to this, there's now 13 citation needed tags left to take care of. 5 are specifically in the ascending and descending chain conditions section. Sgubaldo (talk) 15:29, 3 November 2024 (UTC)

Thanks. XOR'easter (talk) 17:21, 4 November 2024 (UTC)

The first epoch of algebraic invariant theory says "an example, if a rigid yardstick is rotated, the coordinates (x₁, y₁, z₁) and (x₂, y₂, z₂) of its endpoints change ...". How is this related to the article but does not explicitly says about that example? Dedhert.Jr (talk) 07:25, 5 November 2024 (UTC)

I think that line was just trying to explain what "invariant" means. I trimmed the notation, since we don't use it later. 10 {{citation needed}} tags remain. XOR'easter (talk) 21:35, 10 November 2024 (UTC)

Sharpness (cutting)

I have just recently created Sharpness (cutting), with the current focus being on sharpness occurring in nature (sharpness of stones, thorns, teeth, claws, horns, etc.). Is there such a thing as a mathematical definition or theory of sharpness that should be included? I would note that one article that I cited says: "an objective, dimensionless blade sharpness index BSI that relates the energy W_CI (Nm) necessary to initiate a cut to the product of cut initiation depth CI (m), thickness x (m) and fracture toughness J (J/m2) of the testing material BSI = W_CI/CI•x•J where BSI = 0 indicates a blade with ideal sharpness, and an increase in BSI can be interpreted as decreasing sharpness". I don't know what that means. BD2412 T 01:11, 28 October 2024 (UTC)

Try the WikiProject for Physics instead. PatrickR2 (talk) 04:43, 28 October 2024 (UTC)

doi:10.1016/j.jmatprotec.2004.04.297 and the papers that cite it may be useful. –jacobolus (t) 04:59, 28 October 2024 (UTC)

@Jacobolus: Thanks, I will have a look. BD2412 T 13:16, 28 October 2024 (UTC)

Soft cell (shape)

A new class of shapes has recently been published. They are called soft cells - where I've made brief start at an article. I don't have much time to dedicate to this at the moment, but I think it warrants some attention if anyone is interested. Tayste (edits) 22:54, 28 October 2024 (UTC)

@Tayste Well, this leads me to a question: Are there any backgrounds of that tiling discovery? Dedhert.Jr (talk) 04:26, 29 October 2024 (UTC)

Dispute in Algebra

The featured article Algebra has taken onto the dispute by two users, with the reason that the article continues to expand even further or personalization things (or whatever it is). More users for giving points of view in Talk:Algebra#Recent changes to subsection "Polynomials". Dedhert.Jr (talk) 10:29, 30 October 2024 (UTC)

Area of a circle

Please see recent edit history at Area of a circle where some new editor insists that Archimedes proof needs to be labeled as "a logic proof" and that a calculation of the areas of some isosceles triangles needs to be replaced by subdividing the triangles into right triangles and summing their areas instead, in not-well-written English. —David Eppstein (talk) 06:35, 3 November 2024 (UTC)

I agree that these edits are not good. However I hope that someone can improve the readability of this section.

I think the 'not greater' argument can be described in a clear way almost entirely without symbols. It has two parts: (1) any inscribed regular polygon has smaller area than the right triangle and (2) there exist inscribed regular polygons with area arbitrarily close to the circle area. So if the circle area is greater than the triangle area, by (2) there is an inscribed regular polygon with area larger than the triangle area, but this contradicts (1).

The argument for (1) is that the polygon perimeter is less than the circle circumference (as follows from the fact that lines minimize distance between two points) and the polygon's inner radius is less than the circle radius. Since polygon area is one half the perimeter times the inner radius and triangle area is one half the circumference times the circle radius, (1) follows immediately. Fact (2) is extremely intuitive, and could even be acceptable here as self-evident. Archimedes' construction of iterated bisection is a good illustration but probably not a proper proof. Is it clear without doing some extra calculation that the 'gap area' eventually becomes arbitrarily small?

I think it's a really marvelous proof (or almost-proof) but I found its wiki-description rather hard to read. For me a description of the above kind is much easier.

(And if nothing else, symbol $c$ is presently referred to multiple times but not defined!) Gumshoe2 (talk) 09:00, 3 November 2024 (UTC)

MathJax for non-signed-in users in the future

Pinging @Salix alba:

If I understand correctly, every non-signed-in user will be forced to see math as rendered by MathML, beginning in December 2024. But since MathML has many disadvantages in comparison with MathJax, it would be illogical to shove MathML down their throat.

The users who are not signed in can change appearance of their Wikipedia. There's a panel on the right that allows them to change the size of the text, width of the text and also color. However, they should be able to change their math renderer as well. Given that they will be able to change the text, width and color, why not change the math renderer as well? I think everyone would benefit from that.

As an aside, why does the MathJax option read "[...] (for browsers with limited MathML support)"? It assumes that the only reason why one wants MathJax is that their browser has limited MathML support, which is false. Many users label MathML as inferior to MathJax, providing an overflowing supply of reasons, regardless of the level of support of MathML in the browser they use. A1E6 (talk) 17:30, 3 November 2024 (UTC)