Halloween linkage

Perspective drawing often consists of mapping a curved world onto a flat screen. But what if you mapped a polyhedral world onto a curved screen (\(\mathbb{M}\))? Artwork by Szegedi Csaba, 1986. His more recent work is different enough that it’s not obvious they’re the same person.

The hunt for Wikipedia’s disinformation moles (\(\mathbb{M}\)). Wired on coordinated long-term state-level disinformation campaigns on Wikipedia. I couldn’t find their link to the research they report on, but it appears to be “Information Warfare and Wikipedia“(by Carl Miller, Melanie Smith, Oliver Marsh, Kata Balint, Chris Inskip, and Francesca Visser of the Institute for Strategic Dialogue), which focuses on Russian disinformation in their war on Ukraine.

Fibonacci numbers and fractals hiding in geometric optimization problems in symplectic geometry (\(\mathbb{M}\)). I don’t understand symplectic geometry at all but this article kind of makes me want to try. Based on a 2012 paper by Dusa McDuff and Felix Schlenk, and a 2021 paper by Maria Bertozzi, Tara S. Holm, Emily Maw, Dusa McDuff, Grace T. Mwakyoma, Ana Rita Pires, and Morgan Weiler (arXiv:2010.08567).

My colleague and coauthor Vijay Vazirani wins the INFORMS John von Neumann Theory Prize (\(\mathbb{M}\)) “for his fundamental and sustained contributions to the design of algorithms, including approximation algorithms, computational complexity theory, and algorithmic game theory, central to operations research and the management sciences”.

Lost documents from ancient Greek science are still being discovered in palimpsests, parchments that have been scraped clean and rewritten with something else, via modern multispectral imaging techniques (\(\mathbb{M}\)). The latest: a constellation from a lost star catalog by Hipparchus on the Codex Climaci rescriptus from Saint Catherine’s Monastery on the Sinai Peninsula.

A geometrically natural uncomputable function (\(\mathbb{M}\), via; from 2008), reporting on Alexander Nebutovsky’s “Non-recursive functions, knots ‘with thick ropes’, and self-clenching ‘thick’ hyperspheres”. If you embed an \(n\)-dimensional sphere into an \((n+1)\)-dimensional one, you can always continuously move the embedding to the equator, but you may have to move the embedding closer to itself first. How much closer? It’s uncomputable!

Five geometric origami books by Shuzo Fujimoto now public-domain (\(\mathbb{M}\), via). They were originally published in the 1970s and 1980s and focus on polyhedra, tessellations, modular origami, and the like. In Japanese, but with lots of diagrams.

Chris Purcell asks: what do you call those fractal cracking patterns in paint, mud, etc.?

Who will pay the publication fees under new grant-agency rules that all publications must be open access (\(\mathbb{M}\))? “We face a growing risk that the ability to pay APCs – rather than the merits of the research – will determine what and who gets published.” … “I fear that forcing pay-to-play for every paper will end up amplifying existing inequities.”

Claims to have proven the twin prime conjecture and the existence of infinitely many Mersenne primes (\(\mathbb{M}\)) were published by Janusz Czelakowski in a peer-reviewed Polish logic journal. Beyond the obvious mistake in theorem 1.1 of the 1st link (the word “prime” is missing at an important point), other editors in a discussion on Wikipedia (where I found this) were skeptical that model theory and forcing are the right way to prove results like this. After the MathOverflow discussion turned up more serious errors, the editor-in-chief promised a retraction.

New Wikipedia Good Article on kites (\(\mathbb{M}\)), the quadrilaterals, not the toys on strings and not the birds. The article briefly mentions that every non-rhombus kite has sides that are bitangents to two unequal circles. I was unable to source and did not include (although a figure makes it obvious) that this can be reversed. Every two unequal circles have four bitangents forming sides of exactly three quadrilaterals: a convex kite, a concave kite, and an antiparallelogram.

The warm welcome given to edgelords on Twitter by the site’s new owner has led to another mass migration to Mastodon. One of the familiar names making the move is Vi Hart, who posted among other things about 60 whisks tangled together in icosahedral symmetry.

The usual version of the chessboard paradox features seeming dissections of two different-area rectangles into the same set of triangles and trapezoids. Bruce35dc finds a variant with three dissections of the same rectangle, into seven pieces, six out of the seven, and five of the six!

It is a truth universally acknowledged that unless you write your papers with a catchy start, the referees will get bored and stop reading before getting to the important parts. Igor Pak has some advice (\(\mathbb{M}\)).

A few years ago Google search was good enough, and Wikipedia’s bad enough, that I would regularly search Google for “something site:en.wikipedia.org”. Now the tables have turned: James Vincent suggests switching to the Wikipedia mobile app as the default for searches (\(\mathbb{M}\), via) since much of the time what you are trying to find is there or linked from there. Of course, many of my searches seek sources for Wikipedia content, so that wouldn’t help me…