Puzzles
Seven odd little blocks fit together into a perfect cube in 240 different ways
In 1933, Danish polymath Piet Hein was sitting in on a lecture about quantum physics when he sketched a set of seven pieces, each made from three or four unit cubes glued together in every possible irregular way short of a straight line or a cube itself. Martin Gardner popularized the puzzle in Scientific American in 1958: can you fit the seven pieces back together into a single 3×3×3 cube?
Reveal the answer
There are 240 distinct ways to reassemble the seven Soma pieces into a cube, not counting rotations and reflections as different. Beyond the cube, the same seven pieces can build thousands of other recognizable shapes — chairs, castles, animals — which is why the puzzle outlived its origin in a physics lecture.