born Dec. 17, 1908, Grand Valley, Colo., U.S.
died Sept. 8, 1980, Los Angeles, Calif.
U.S. chemist.
He studied at the University of California at Berkeley and later taught there and at the University of Chicago and UCLA. With the Manhattan Project , he helped develop a method for separating uranium isotope s and showed that tritium is a product of cosmic radiation. In 1947 he and his students developed carbon-14 dating , which proved to be an extremely valuable tool for archaeology, anthropology, and earth science and earned him a 1960 Nobel Prize.