German physicist. He taught theoretical physics at the Univ. of Gö ttingen from 1921 to 1933, when he fled to Britain where he taught principally at the Univ. of Edinburgh (1936-53). In 1921 he gave a very precise definition of quantity of heat, the most satisfactory mathematical statement of the first law of thermodynamics. In 1926 he collaborated with his student W. Heisenberg to develop the mathematical formulation that would adequately describe Heisenberg's first laws of a new quantum theory. He later showed, in the work for which he is perhaps best known, that the solution of the Schrö dinger equation has a statistical meaning of physical significance. His later work concerned the scattering of atomic particles and calculations dealing with the electronic structures of molecules. In 1954 he shared a Nobel Prize with Walther Bothe (1891-1957).