Talk:Proof without words

Proof of Pythagorean theorem

I'm having some difficulty seeing how the diagram constitutes a proof of the Pythagorean theorem. Perhaps it is too subtle for me. But even if it is a proof, does it apply to all right angled triangles, or only 3-4-5 ones? Rjm at sleepers (talk) 04:40, 24 June 2008 (UTC)

All of them. Try to express the area of the square in two different ways. It seems self-evident to me, and apparently to the author of my reference. Nousernamesleft^{copper, not wood} 19:45, 24 June 2008 (UTC)

It is an evergreen that has graced more than one cover of a maths book. 2A01:CB0C:CD:D800:D987:899A:3E01:2296 (talk) 08:21, 30 October 2022 (UTC)

The article said to "see" the historical Chinese-text diagram File:Chinese pythagoras.jpg in 2008, with no explanation in all this time of what was happening. Great if you already know it, not so much if you don't. I've rewritten the section to give a clearer explanation, and used a different illustration. --Belbury (talk) 09:03, 30 October 2022 (UTC)

GA Review

This review is transcluded from Talk:Proof without words/GA1. The edit link for this section can be used to add comments to the review.

Hi there! I will be reviewing this article's GAN. I'm very concerned about the article's short length and failure to fulfill WP:GACR for not being broad in its coverage. Perhaps you could add a little more information about the history behind proofs without words. If you would take a look at this link and this link, you would find some information about the history of proofs without words. Use those sources as a starting point, and expand your new information by doing a little more research into this topic.

Furthermore, talk a little bit about proofs without words more in general. Why have they captured people's attention recently? What exactly is so special about them? Can they be considered proper proofs? You can see a short discussion of proofs without words here.

As you can see by the links I provided, a simple search of Google Books can give you tons of information about anything you want. Use it! I'm confident that this article can improve dramatically once you add a little more information.--Edge3 (talk) 19:54, 10 August 2009 (UTC)

Thank you for your comments. I am unlikely to have time to do much work on the article myself, but I have left a note at the WikiProject Mathematics talk page to alert other editors who may be able to contribute. Gandalf61 (talk) 11:00, 11 August 2009 (UTC)

Does look a bit sparse at the moment. I'd have thought there were enough proofs of this type for a category which would reference illustrations of this type in other articles, for instance a proof of Desargues' theorem or some things from Visual Calculus if it is developed. And how about tools like Penrose graphical notation? Or a series of pictures like the Eversion of the sphere?There's also dynamic images which illustrate things which couldn't have been done in the past and of which there a whol;e host at the Wolfram demonstrations project. Dmcq (talk) 23:11, 11 August 2009 (UTC)

I'm failing this nomination due to the lack of improvements made to the article.--Edge3 (talk) 14:47, 21 August 2009 (UTC)

Suggestion for a subsection topic

In rewriting systems one ca do diagrammatic proofs (without words) that have a precise meaning. Take a look at one of the books listed in references there. Sadly, no such proof appears in any of the related articles yet. Pcap ping 06:27, 23 August 2009 (UTC)

Assessment comment

The comment(s) below were originally left at Talk:Proof without words/Comments, and are posted here for posterity. Following several discussions in past years, these subpages are now deprecated. The comments may be irrelevant or outdated; if so, please feel free to remove this section.

Needs significant expansion. There are many more proofs without words, and a history and culture associated with them. Geometry guy 23:08, 21 August 2009 (UTC)

Last edited at 23:08, 21 August 2009 (UTC). Substituted at 02:31, 5 May 2016 (UTC)

Being clear about proofs without words vs. formal proofs

I added some material to make it more obvious that mathematicians typically would not accept a proof without words as a genuine proof of something. Pictures can easily be misleading, by glossing over important details that come to light when you approach the argument deductively. I really would not want a casual reader to come across this page and get the idea that they can substitute a picture or informal thought experiment for a rigorous argument when they want to prove something mathematical—as long as they hang onto that idea it will harm their mathematical development. I don't think many people get much experience with proofs in their grade school math classes (definitely not in the U.S. where I live) so it seems to me like there's a real risk of that happening if we're not careful to avoid it. Mesocarp (talk) 03:16, 27 October 2022 (UTC)

Yes, the layperson should understand that these are classroom demonstration objects. It is just fun to point out to the student that everything is right there in the picture. In maths folklore we have a zoo of jocular "proof principles" that are not proofs at all, e.g. proof by obfuscation, proof by mutual attrition, proof by total intimidation. Also, "without words" is itself a bit tongue in cheek. I find I do need to talk myself through the bits and pieces that are on display before I understand what is going on. 2A01:CB0C:CD:D800:D987:899A:3E01:2296 (talk) 08:19, 30 October 2022 (UTC)

Proof by Lego/Meccano

Sometimes considerable clarity is gained in a proof without words by having moving parts in the graphical representation. This can be achieved with construction toy and the modern overhead projector which illuminates from above (and which actually gives a depth of focus of a good few inches --- it's not just for display on paper). 2A01:CB0C:CD:D800:D987:899A:3E01:2296 (talk) 08:15, 30 October 2022 (UTC)