Wolfgang Ketterle (born 1957), German physicist. He received the 2001 Nobel Prize for Physics, along with two others, for his work on Bose- Einstein condensates (BECs), the fifth state of matter". These are formed when atoms are cooled to a fraction of a degree above absolute zero. The atoms then behave as if they were one large atom. Ketterle has used this coherence to form an atom laser, the particle equivalent of a normal (light) laser. BECs could have many uses in nanotechnology and precision measurement. Ketterle is the John A. MacArthur Professor of Physics at the Massachusetts Institute of Technology (MIT), USA. Photographed in 2001."