Researchers: A Rubik’s Cube Can Be Solved in no More Than 20 Moves
By Chris Brandrick
Any Rubik’s Cube configuration can be solved in 20 moves or fewer, according to new research.
The recent puzzle-based findings come from a small group of researchers, including a university mathematician and a Google engineer. Collectively they found that every single one of a Rubik’s Cube’s massive 43,252,003,274,489,856,000 combinations can be solved in just 20 moves or less.
This staggeringly small number of moves, known as God’s Number, was found to be accurate thanks to the help of 35 years worth of computing time–time which was spent number crunching.
According to the research, the intensive number cruncing, which was completed by Google’s own computers, broke the problem down into smaller problems. As the researchers put it on their site, “We broke the problem down into 2,217,093,120 smaller problems, each comprising 19,508,428,800 different positions. Each of these subproblems was small enough to fit in the memory of a modern PC, and the way we broke it down allowed us to solve each set rapidly.”
The researcher’s site has more information on how they reached God’s Number. But for those who never did manage to solve the Rubik’s Cube, myself included, the Internet has plenty of guides designed to stop you from resorting to sticker-swapping.