How many moves does it take to solve a Rubiks Cube?
The Rubik’s cube is a toy that pretty much everyone is familiar with, but it also has become a proving ground for researchers in fields as diverse as artificial intelligence, operations, and search algorithms. The simple 3x3x3 cube with colored stickers has fascinated and baffled people since its introduction in the late 1970s. The simple game is so complex that there are over 43 quintillion (4.3252×1019) states, and any of them can be reached from any other. While one could spend a lifetime checking each configuration to see if it leads to the solution, there are a whole host of solutions published on the web. But, what is the fastest way to solve a Rubik’s cube? In 1997, Richard Korf, a professor of computer science at UCLA, said that his research showed that a Rubik’s cube could be solved in a median of 18 moves, and no more than 20 should be needed. However, he was not able to prove this. The lowest provable number of moves needed to solve a Rubik’s cube was 27—until now. A pair of
