Rubik's Cube Turns 40

There are only a handful of toys that last more than a generation. But the Rubik's cube, which celebrates its 40th birthday. The Rubik's cube was invented in 1974 by Erno Rubik, a Hungarian architect, who wanted a working model to help explain three-dimensional geometry. After designing the “magic cube” as he called it (twice the weight of the current toy), he realised he could not actually solve the puzzle. The more he moved the coloured squares, the more mixed up they became. “It was a code I myself had invented!” he wrote. “Yet I could not read it.”

The cube, made up of nine coloured squares on each side, can be rearranged in 43 quintillion different ways. That is 43,000,000,000,000,000,000.