What a Flake

Computers get the hang of ice-crystal growth

With a camera-equipped microscope of his own making, Kenneth G. Libbrecht shoots some of the world’s most stunning photographs of snowflakes. Since October, four of the physicist’s images have adorned U.S. postage stamps. Each stamp displays an exquisitely intricate, burst-shaped crystal that, because of the photographer’s distinctive lighting, glows like polished metal.