SOMA is a three-dimensional puzzle invented in 1936 by Danish author and mathematician Piet Hein. "Problems worthy of attack, prove their worth by hitting back," stated Hein. The puzzle is based on the principle that all irregular shapes that can be formed by combining no more than four cubes, all the same size and joined at their faces, can be combined to form a larger cube. The seven simple shapes can also be combined to form a multiplicity of geometric shapes as outlined at www.fam-bundgaard.dk/SOMA/SOMA.HTM
SOMA has appeared in Scientific American, and the ability to solve a SOMA puzzle is often linked to level of intelligence. SOMA puzzles are used by teachers, psychologists, and enthusiasts around the world. Woodsmiths" SOMA is made of cubes measuring 2.5 cm forming a large cube of 7.5cm x 7.5cm. The cubes are made of a variety of hardwoods and are finished with tung oil.