Willard Frank Libby (December 17, 1908 - September 8, 1980) was an American physical chemist noted for his role in the 1949 development of radiocarbon dating, a process which revolutionized archeology. He received his B.S. in 1931 and Ph.D. in 1933 in chemistry from the University of California, Berkeley, where he then became a lecturer and later assistant professor. He spent the 1930s building sensitive geiger counters to measure weak natural and artificial radioactivity. Awarded a Guggenheim Fellowship, he spent most of 1941 at Princeton University. After the start of World War II, he worked on the Manhattan Project. was responsible for the gaseous diffusion separation and enrichment of the uranium-235 which was used in the atomic bomb on Hiroshima. In 1945 he became a professor at the University of Chicago. In 1954, he was appointed to the U.S. Atomic Energy Commission. In 1959, he became Professor of Chemistry at University of California, Los Angeles (UCLA), a position he held until his retirement in 1976. He died in 1980 at the age of 71.