Urey, Harold

Urey, Harold (Clayton) (1893–1981) chemist; born in Walkerton, Ind. With great persistence he managed to get a college education, and then, after working for a chemical company during World War I, he finally obtained his Ph.D. in physical chemistry from the University of California: Berkeley (1923). He worked on the theory of atomic structure with Niels Bohr in Copenhagen before joining the faculty at Columbia University (1929–45). He won the 1934 Nobel Prize in chemistry for separating the isotope deuterium from hydrogen; instead of attending the prize ceremony, he stayed at home to attend the birth of his third daughter. During World War II he directed the search to separate uranium-235 from uranium-238 for the Manhattan project. After the war he took the lead in questioning the ethics of using nuclear weapons. At the Enrico Fermi Institute of Nuclear Studies (University of Chicago, 1945–58), he pondered the origin of the elements, their abundance in stars, and the derivation of planets. Among his other important contributions was a technique that used oxygen isotope-bearing minerals to date geological formations and to measure annual water temperatures. His publications include The Planets: Their Origin and Development (1952). At the University of California: San Diego (1958–81) he analyzed lunar rocks from the Apollo missions. Highly regarded, he won more than 30 awards as well as honorary degrees from 25 universities.