“I just proved that all positions of Rubik’s cube can be solved in 23 or fewer face turns. (The link is to the proof of 25; the proof of 23 is essentially the same with just a lot of sets solved.) This proof was made possible by the generous contribution of CPU time from Sony Pictures Imageworks with the help of John Welborn, on the same machines used for movies such as Spider-Man 3 and Surf’s Up. I’m currently working on 22.”
