Rubik’s Cube Proof Cut To 25 Moves

The internet is abuzz over the latest mathematical proof by Tomas Rokicki, former HP Lab researcher.

This article posted to SlashDot provoked a huge response:

A scrambled Rubik’s cube can be solved in just 25 moves, regardless of the starting configuration. Tomas Rokicki, a Stanford-trained mathematician, has proven the new limit (down from 26 which was proved last year) using a neat piece of computer science. Rather than study individual moves, he’s used the symmetry of the cube to study its transformations in sets. This allows him to separate the ‘cube space’ into 2 billion sets each containing 20 billion elements. He then shows that a large number of these sets are essentially equivalent to other sets and so can be ignored. Even then, to crunch through the remaining sets, he needed a workstation with 8GB of memory and around 1500 hours of time on a Q6600 CPU running at 1.6GHz. Next up, 24 moves.

Good work Tom!
It figures though – you do cutting edge research for years at a top industrial lab, and nobody notices.
Prove how to solve Rubik’s cube, and now you’re a rock star.

Leave a Reply

Your email address will not be published. Required fields are marked *