Linkage

Zuse describes breadthfirst search in 1945 (pp. 96–105 of link; G+) as noticed by Jeff Erickson. This is already 14 years earlier than the textbook date for the discovery of BFS, but Jeff thinks earlier instances are out there.

The Poincaré Homology Sphere (G+). Evelyn Lamb explains what this space is and why it’s interesting.

Less is more (G+). This Crooked Timber post and its discussion raise an interesting philosophical question about academic productivity: Is it better to have a small number of publications, but only in top venues, or to have the same amount of topvenue productivity plus a lot of lowerlevel publications?

Dot grid paper for writing mathematics (G+). I’m thinking of switching from my habitual squared Moleskines to something nicer.

Squared squares video from Numberphile (G+). The recreational math problem that began Bill Tutte’s work in graph theory.

Selfsimilar polygonal tilings (G+). Richard Green shares an image by Michael Barnsley and Andrew Vince of a quasiperiodic tiling with two similar prototiles, such that the whole tiling is similar to a subdivided copy of itself.

Lance Fortnow’s annual listing of which theoreticians are moving where (G+), including the news that Vijay Vazirani is coming to UC Irvine! Here’s a related reddit post by a former student, calling Vijay “an amazing professor”, one of the best at his former institution.

UC Irvine recognized as a Hispanic Serving Institution (G+). We’re better known for our evenbigger Asian population, but a quarter of our students are Hispanic/Latinx, and we’re one of only three top100 research universities in the US to be distinguished in this way.

Does pigeonhole degrade gracefully? (G+) A new Stanford theory blog discusses a sharp phase change in the maximum number of almostdisjoint sets of a given size, as the size drops below roughly the square root of the total number of elements.

“A Puzzle of Clever Connections Nears a Happy End”, Quanta Magazine (G+). Andrew Suk’s almostcomplete solution to the happy ending problem, getting the correct exponential ( not ) for how many points in general position in the plane are needed to guarantee the existence of a convex gon.

Lebanese civil engineering professor with a valid visa and multiple past entries to the US denied entry to present his research at a conference (G+). The sponsoring organization (ASCE) issued only a mealymouthed nonprotest.

Joris Laarman’s Bone Chair (G+). An early and pioneering work of generative design, a technique that is now becoming more commonplace and popular for its organic “art nouveau” forms and minimal use of materials. See the G+ post for several more recent generative design links.

Ruler, compass and helix constructions (G+). From a post by @jherzli on mathstodon.xyz, a new social media platform for mathematicians.