born April 29, 1893, Walkerton, Ind., U.S.
died Jan. 5, 1981, La Jolla, Calif.
U.S. scientist.
He received his doctorate from the University of California at Berkeley and thereafter taught at various universities. He was awarded a Nobel Prize in 1934 for discovering deuterium and heavy water . He was a key figure in the development of the atomic bomb ; his group worked on the gaseous diffusion process for separation of uranium-235. He devised methods for estimating the temperature of ancient oceans, theorized on the compositions of primordial atmospheres, and studied the relative abundances of the elements, making fundamental contributions to a widely accepted theory of the origin of the Earth and other planets in The Planets , (1952).