Attempting to improve on the face-center cubic lattice structure of opals in order to make “photonic crystals,” an engineering professor and his graduate students experimented with ways to pack a small number of tiny spheres.

They discovered that the colloidal particle clusters they made have exotic structures predicted by pure mathematicians in 1995.

The uncanny correspondence between mathematics and physics doubtless prompted “Science” editors to picture the clusters on the July 25 cover.

University of California, Santa Barbara press release

Blaaderen, CHEMISTRY: Colloidal Molecules and Beyond, Science 2003 301: 470-471