The Invertible Cube by Paul Schatz (1898-1979) - sculptor, mathematician, inventor
In 1929 Paul Schatz discovered that a cube can be split into three parts, the central one of which (photo above) is a flexible belt which allows the form to be completely inverted. The short edges act as hinges. In this inversion the belt undergoes a surprising and fluid sequence of different combinations of triangular and hexagonal / cubic forms on the inside / outside of the shape.
A beam of wood is, topologically, identical with a cube, and so is one invertible cube segment with the wooden beam. In The Same Thing / Slow Motion the two forms follow the outline of two segments of the Invertible Cube, which is also examined in Encircling A Spatial Tear, Parallel Diagonals and The Shape Of Information.