John C. Baez 14 days ago
More precisely, take the regular icosahedron whose 12 vertices are
(±1,±Φ,0), (0,±1,±Φ), (±Φ,0,±1)
where Φ = (1 + √5)/2 is the golden ratio. Take
points (vertices),
lines (between nearest-neighbor vertices),
and
planes (containing triples of nearest neighbors)
in ℚ[√5]³.
(2/n)