Rubik’s Cube Can Be Solved in Maximum of Twenty Steps

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Any Rubik’s Cube problem can be solved in maximum of 20 steps, according to new research. With about 35 CPU-years of idle computer time donated by Google, a team of researchers has essentially solved every position of the Rubik’s Cube™, and shown that no position requires more than twenty moves.

It took fifteen years after the introduction of the Cube to find the first position that provably requires twenty moves to solve; it is appropriate that fifteen years after that, we prove that twenty moves suffice for all positions.

The recent puzzle-based findings come from a small group of researchers, including Morley Davidson of Ohio’s Kent State University, Google engineer John Dethridge, German math teacher Herbert Kociemba and Tomas Rokicki, a Californian programmer. 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.

The researcher’s site has more information on how they reached God’s Number. The term “God’s number” refers to the minimum number of moves that it takes to solve a puzzle like the Rubik’s Cube.

History of Maximum Moves

The Rubik’s Cube originally called the “Magic Cube” was invented in 1974 by ungarian sculptor and professor of architecture Erno Rubik.

    Year – Maximum moves for solution
    1981 – 52 moves
    1992 – 42 moves
    1992 – 39 moves just one month later
    1992 – 37 moves just one day later
    1995 – 29 moves
    2005 – 28 moves
    2006 – 27 moves
    2007 – 26 moves
    2008 – 22 moves
    2010 – 20 moves