...it also works with random points

These are the self-intersecting onions @jeffgerickson was mentioning

CRA finally copies MathJobs: cra.org/cv-database/

How to peel self-intersecting onions: arxiv.org/abs/1909.00263

Update on the Safe ToC initiative: windowsontheory.org/2019/08/30

Sandy Irani describes progress in combatting harassment and discrimination at theoretical computer science conferences, and calls for volunteer advocates to serve as contact points at conferences.

\$400 online calculus course for full (transferrable) credit at Pitt: outlier.org/calculus

While it's tempting to call this a MOOC, but it's not open. Let's give them the benefit of the doubt and call it a MOC.

A generic closed curve that is not isotopic to any 36-gon, derived from Ringel's non-stretchable arrangement of 9 pseudolines, which was derived in turn from Pappus's hexagon theorem.

jstor.org/stable/3029218
(Written when the author was 11, and submitted when he was 12. See the affiliation "Jr. High School 246" on the last page of the article, and the letter from the author's mother on page 91 of the same issue.)

aeon.co/essays/how-european-sa — "Soon after this, mariners started cramming for exams. Instead of paying 36 florins for an entire winter of lessons, Amsterdam-based mariners paid just 6 florins for a crash course focused on the oral and written portions of the tests. Later manuscript workbooks confirm this strategy: students often focused on the questions they knew would be on their exam. Teachers at the close of the 17th century were already ‘teaching to the test’."

Mental Health in the Mathematics Community, by Mikael Vejdemo-Johansson, Justin Curry, and Julie Corrigan, in the most recent Notices of the AMS.
ams.org/journals/notices/20190

Consider unfollowing that person that always leaves you feeling worse about things.

Sorry, that's Panckoucke with a P. (I have no idea where that M came from.)

Here's his actual theorem statement: "Every rectilinear polygon can be split into as many triangles as it has sides, minus two."

The earliest PROOF of the polygon triangulation theorem that I'm aware of is an unpublished 1899 manuscript of Dehn! See maths.ed.ac.uk/~v1ranick/paper

...Following a rabbit hole inspired by the Numberphile's recent video on Dehn invariants: youtube.com/watch?v=eYfpSAxGak

A triangulated polygon, from Les Amusemens Mathématiques by André-Joseph Mancoucke, 1749. This is the earliest appearance I know of the theorem (stated without proof) that every simple polygon can be triangulated by diagonals. In particular, Mancoucke predates both Meister's (1770) and Poinsot's (1809) seminal treatises on polygons.

Depressingly hilarious.

No, you're not allowed to say "Well, at least we don't have these problems in MY department!"

thelastpsychiatrist.com/2011/0

Show more

A Mastodon instance for maths people. The kind of people who make $\pi z^2 \times a$ jokes.

Use $ and $ for inline LaTeX, and $ and $ for display mode.