Thursday, December 09, 2004

Geometry of the Universe

The 5 Platonic Solids

From http://www.geom.uiuc.edu/~sudzi/polyhedra/platonic.html
The Greek philosopher Plato, who was born around 430 B.C., wrote about these five solids in a work called Timaeus. Historical accounts vary a little, but it is usually agreed that the solids themselves were discovered by the early Pythagoreans, perhaps by 450 B.C. There is evidence that the Egyptians knew about at least three of the solids; their work influenced the Pythagoreans.

In any case, Plato mentioned these solids in writing, and it was he who identified the solids with the elements commonly believed to make up all matter in the universe. In Plato's times, people believed that all things were made up of five different atoms. They were fire, air, water, earth, with the fifth being the cosmos (the universe itself).

Plato identified fire atoms with the tetrahedron, earth atoms with the cube, air atoms with the octahedron, water atoms with the icosahedron, and the cosmos atoms with the dodecahedron.