A solid dissection puzzle invented by Piet Hein during a lecture on Quantum Mechanics by Werner Heisenberg. There are seven soma pieces
composed of all the irregular face-joined cubes (polycubes)
with cubes. The object is to assemble
the pieces into a cube. There are 240 essentially distinct
ways of doing so (Beeler 1972, Berlekamp et al. 1982), as first enumerated
one rainy afternoon in 1961 by J. H. Conway and Mike Guy.
A commercial version of the cube colors the pieces black, green, orange, white, red, and blue. When the 48 symmetries of the cube, three ways of assembling the black
piece, and
ways of assembling the green, orange, white, red, and blue pieces are counted, the
total number of solutions rises to .