Cornell, Eric Allin (1961-...), an American physicist, won a share of the 2001 Nobel Prize in physics for discovering and studying a state of matter known as a Bose-Einstein condensate (BEC). A BEC is a cluster of atoms that behave somewhat as if they were a single atom. Cornell shared the prize with his colleague, the American physicist Carl E. Wieman; and with the German physicist Wolfgang Ketterle, who worked separately on BEC's. The condensates are named for the physicists Satyendra Nath Bose of India and Albert Einstein of Germany, who proposed in the 1920's that BEC's could be created.