It is an unexplained fact that objects with icosahedral symmetry occur in nature only at microscopic scales. Examples include quasicrystals, many viruses, the carbon-60 molecule, and some beautiful protozoa in the radiolarian family.
Mathematical Impressions: Symmetric Structures
Mathematical Impressions: Geometry of Spaghetti Code
A sculpture project built entirely with right angles combines math and art in subtle and surprising ways.