The Coolest Thing I Learned Today
---------------------------------

12/28/19:
Leela Chess Zero (Lc0) is an open-source, AlphaZero-inspired engine which uses tree search in conjunction with a deep network for value and policy estimation. In April 2019 it won the Chess.com Computer Chess Championship, becoming the first NN-based engine to do so. As of today, a version of it is playable on Chess.com. (Ref: Lc0 GitHub Wiki, Chess.com.)

12/29/19:
The DARPA Z-Man program supports the development of reversible adhesive climbing aids that will allow humans to scale walls like geckos. So far, the program has produced e.g. Z-Man grips (a full-body mechanical climbing device) and Geckskin (a reversible adhesive based on "the mechanics of gecko feet"). (Ref: DARPA, Popular Mechanics, UMass.)

12/30/19:
You can (classically) recondition worms to change their preferences for stimuli. For example, you can get an earthworm to recoil from rose oil (the conditioned stimulus) by pairing it with an unconditioned stimulus of butanol. As Catharine Rankin of UBC has shown, even 302-neuron roundworms can learn and remember stimuli. (Ref: Angelfire.com, Charles I. Abramson, Catharine H. Rankin.)

12/31/19:
The Great Internet Mersenne Prime Search (GIMPS) is an ongoing distributed search for Mersenne primes (primes of the form 2^n - 1). To date, it has found 17 of the 51 known Mersenne primes, with the latest (the 24-million-digit 2^82589933 - 1) being discovered on December 7th, 2018. Although large prime numbers are extremely sparse, there exist fast algorithms for finding Mersenne primes, so searching for Mersenne primes is an effective way to discover primes in the "wasteland" of large numbers. Currently, all of the largest known primes are Mersenne primes. (Ref: Wikipedia, THatP 64.)