Talk:Thrackle

The origin of the word thrackle

Here is an explanation for the origin of the word thrackle by Conway; this external link could be included in the article. Apart from that, I also did some OR in order to find out whether the word had been recorded somewhere before Conway introduced it into mathematics, and I found it being used hapax in the work The Zozimus papers : a series of comic and sentimental stories and legends (1882) (a collection of rhymes by the Irish poet Zozimus): "So put your goods in the thrackle..." --though thrackle, in this context, does not seem to mean "tangle" as Conway's story has it. --Omnipaedista (talk) 09:01, 27 November 2009 (UTC)

Transversality

The concept of a transverse intersection of two curves in the plane usually applies only to continuously differentiable curves.

Because this article does not mention differentiability, it would greatly improve this article if instead of (or in addition to) the link to the Transversality article, this article included an unambiguous definition of what a "transverse intersection" means in the context of thrackles.

I hope someone knowledgeable about this subject can modify this article accordingly. — Preceding unsigned comment added by 2601:200:c082:2ea0:189e:f594:5a2e:f75e (talk • contribs) 17:40, 15 September 2023 (UTC)

Intuitively, it just means that when two curves touch they must cross. Defining it accurately and rigorously is...not intuitive. Probably the simplest is that every point of intersection must have a neighborhood ambient isotopic to the neighborhood of the crossing point of two lines. Anyway, what we should define is what the crossing is, not what it is not. —David Eppstein (talk) 18:12, 15 September 2023 (UTC)

No such thing as a Jordan Arc

There is a Jordan Curve, but AI has never heard of Jordan Arc. 173.164.209.26 (talk) 22:25, 4 January 2024 (UTC)

"Jordan arc": approximately 3,790 hits on Google Scholar. Find a less-ignorant AI, or think for yourself. —David Eppstein (talk) 22:44, 4 January 2024 (UTC)