Margaret Wertheim in the New York Times:
At the dawn of the scientific revolution, the German astronomer Johannes Kepler was struck by a vision. Pondering the distances between the planets, he realized that the sizes of their orbits could be explained by a nested set of Platonic solids.
Known to the Greeks as the “cosmic figures,” these five forms – the tetrahedron, the cube, the octahedron, the dodecahedron and the icosahedron – have the property of being perfectly regular.
Kepler’s vision turned out to be a mirage, as his own research on planetary orbits eventually proved. But the mystique of these solids has endured and in a small, quixotic way, Kepler’s fantasy has finally been realized. Dr. Wayne Daniel, a retired physicist and puzzle expert, has designed an interlocking wooden puzzle that is a complete set of Platonic solids. Like a Russian matryoshka doll, each layer peels away to reveal a smaller form within, only in this case each layer has a different geometry.
More here.