Crystal Of Green Light Bends Matter

Jens Lönn writes: "The Kapitza-Dirac effect is the diffraction of a beam of particles, electrons in particular, by a standing wave of light. One can interpret it as waves of matter diffracted from "crystals" made of light, it's like matter and light swap roles. It was predicted in 1933 by a pair of future Nobel Prize winners, Russian Peter Kapitza (1894-1984) and Englishman P.A.M. Dirac (1902-84), but the technology needed to demonstrate it didn't exist at the time. It wasn't until April 11, 2001, when it was observed for the first time in Herman Batelaan's lab in the Behlen Laboratory for Physics at the University of Nebraska - Lincoln. This is the first time _ever_ that scientists have shown that light can bend matter, not just the opposite."