Prodigi

# Five Tetrahedra, Winter Wall Art Poster

## Five Tetrahedra, Winter Wall Art Poster

Prix habituel $8.00 USD Prix habituel Prix promotionnel$8.00 USD
En vente Épuisé
Size

Impossible de charger la disponibilité du service de retrait

Let $$\phi = \frac{1}{2}(1 + \sqrt{5})$$ be the golden ratio. Start with a cube aligned with the Cartesian axes. Inscribe a regular tetrahedron whose vertices are alternate vertices of the cube. Rotate this tetrahedron 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 tetrahedra has icosahedral symmetry.

Rotations of space that preserve the union of the five tetrahedra permute the set of five tetrahedra by an even permutation'' (a composition of an even number of swaps). Conversely, every even permutation on the set of five tetrahedra 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.

An economical lustre poster paper with a high white, satin finish and smooth microporous coating for accurate photo reproduction. The smooth, satin finish and wide colour gamut make this an excellent substrate for posters and professional photographs.
Afficher tous les détails