Linkage

IEEE has a pseudoscience problem (\(\mathbb{M}\), via). “Unfortunately, bad science published by IEEE isn’t limited to boring applications of boring algorithms to boring data”: the post goes on to describe IEEE publications about computer-enhanced ayurveda, astrology, the supernatural potential of 5G cellphone signals in scientific traditional Chinese medicine, electro-homeopathy, and even two recent papers on perpetual motion.

My late cousin is a Jeopardy clue (\(\mathbb{M}\)): “David Baszucki & Erik Cassel navigated obbys & became tycoons as creators of this platform for creating 3d worlds”.

If not all rounded triangles are Reuleaux triangles, it stands to reason that not all rounded tetrahedra are Reuleaux tetrahedra, the intersections of four spheres each centered at a point where the other three cross (\(\mathbb{M}\)). Here’s another one: the elliptope, the space of positive semi-definite matrices with unit diagonal. For \(3\times 3\) matrices, there are three off-diagonal terms and you get a three-dimensional curved tetrahedron sitting inside a unit cube. It’s a special case of a spectrahedron. Via a Blue Sky post whose image makes clear that it is has a quite different geometry than the Reuleaux tetrahedron: the four tetrahedral faces meet at the straight line-segment edges of a regular tetrahedron, and pillow outward from there. Instead the Reuleaux tetrahedron’s edges are circular arcs where two spheres meet.

Generative art with a technical drawing pen on a pen plotter, by Jeff Palmer. Squiggly curves from “a physics simulation gone wrong”.

The U.S. weather enterprise: a national treasure at risk (\(\mathbb{M}\)), an unusually strong statement about the consequences of Trump’s irresponsible science policy from a major scientific society, the American Meteorological Organization.

Polynomial bounds in the apex minor theorem (\(\mathbb{M}\)). A new preprint by Kevin Hendrey and David Wood shows that \(H\)-minor-free graphs of radius \(r\) have treewidth polynomial in \(\vert H\vert\) and \(r\).

Facebook blocks searches for emergency information about a cyclone menacing Australia (\(\mathbb{M}\)), blaming the problem on “a technical glitch”, but commenters speculate that it may instead have been political, triggered by language connecting the storm to global warming.

Irene Zhang’s postmortem of University of Washington systems and networking lab sexual harassment and bullying investigation (\(\mathbb{M}\)), naming names. “No one has faced any consequences or repercussions”.

Mystery subdivision of a square into acute triangles. The explanation.

Leading AI chatbots have been infected by Russian propaganda (\(\mathbb{M}\)).

Nature Research Intelligence (\(\mathbb{M}\)). On those AI-generated “summaries of the state of scientific research areas” taking over Google search results for those areas, who’s generating them, from the aptly-named Not Even Wrong.

Non-Euclidean wood joinery. Dianea makes and posts a photo of a wooden double Penrose triangle.

John Baez suggests making an off-site backup for the arXiv. The site in question being the US. The arXiv used to have many international mirror sites but they were deemed unnecessary and shut down last year. Maybe not so unnecessary after all?

Hyperbolic strawberry rhubarb pie for \(\pi\) day.

Nine unsolved mysteries in mathematics (\(\mathbb{M}\), archived). Scientific American gets several mathematicians to describe their favorite open problems.