Five Cubes, Autumn Crew Neck Sweatshirt

Let \(\phi = \frac{1}{2}(1 + \sqrt{5})\) be the golden ratio. Start with a cube aligned with the Cartesian axes and rotate the cube by multiples of one-fifth of a turn about the axis through \((0, 1, \phi)\) (or any other axis obtained by permuting coordinates). The resulting union of five cubes has icosahedral symmetry.

Rotations of space that preserve the union of the five cubes permute the set of five cubes by an ``even permutation'' (a composition of an even number of swaps). Conversely, every even permutation on the set of five cubes is effected by a unique rotation of space. The group of rotation symmetries of the union is isomorphic to the alternating group on five letters.

Classic crew-neck sweatshirt. Set-in sleeves and a high cotton count.