Any configuration of a Rubiks Cube can now be solved in 26 moves, or less, according to Dan Kunkle and Professor Gene Cooperman at Bostons Northeastern University.
London, Aug.17 : Any configuration of a Rubik's Cube can now be solved in 26 moves, or less, according to Dan Kunkle and Professor Gene Cooperman at Boston's Northeastern University.
"We don't yet have a proof that 25 moves suffice, but we have several new directions to try that we hope will get us there before the end of the year," Kunkle told The Daily Telegraph.
The ultimate solution to the Rubik's cube has come closer thanks to hours of number crunching conducted on a supercomputer, which took 63 hours to crank out the proof.
Kunkle and Cooperman said they initially used the brute force method of trying various combinations in the computer, relying on an extra 7000 gigabytes of storage, but later resorted to a two-step technique for working out their calculations.
Initially, they programmed the supercomputer to arrive at one of 15,000 half-solved solutions that they knew could be fully solved with a few extra moves. This suggested that any disordered cube could be fully solved in a maximum of 29 moves, but that most cubes took 26 moves or fewer.
The researchers then focused on the small number of "problem" configurations that required more than 26 moves, using the supercomputer to search for the best way to fully solve them. As it turned out the supercomputer was able to fully solve all of these problem cases in fewer than 26 moves.
The study brings scientists one step closer to finding "God's Number" which is the minimum number of moves needed to solve any disordered Rubik's cube.
It was so named by two researchers in 1982 because God would only need the smallest number of moves to solve a cube. Theoretical work suggests that God's Number is in the "low 20s".
Kunkle and Cooperman announced their findings at the International Symposium on Symbolic and Algebraic Computation in Waterloo, Ontario.
Rubik's Cube, invented in the 1970s by Erno Rubik of Hungary, was launched in earnest by Ideal Toys in 1980.
ANI