84. WIND SPINNER – TETRAHEDRAL COMPOUND

A wind spinner is a creation which uses the power of the wind to make it spin on its axis. A great variety of spinners is available for purchase. The ingenious spinner pictured is more mathematical: a compound of two tetrahedra.

There are various compounds of the regular polyhedra; some of the prettier are the compounds of five tetrahedra, ten tetrahedra, and five cubes.

Of course, just mounting this compound of two tetrahedra on a pivot would not make a wind spinner. If you look closely, you will see that some of the polyhedral faces in the central band have been omitted, forming cups to catch the wind.


http://paulscott.info/polyhedra/compounds/duals_comps.html

http://en.wikipedia.org/wiki/Polyhedral_compound