Willard Frank Libby
Born: 17 December 1908, Grand Valley, CO, USA
Died: 8 September 1980, Los Angeles, CA, USA
Affiliation at the time of the award: University of California, Los Angeles, CA, USA
Prize motivation: "for his method to use carbon-14 for age determination in archaeology, geology, geophysics, and other branches of science"
Field: nuclear chemistry
Prize share: 1/1
Carbon is a fundamental component in all living material. In nature there are two variants, or isotopes: carbon-12, which is stable, and carbon-14, which is radioactive. Carbon-14 forms in the atmosphere when acted upon by cosmic radiation and then deteriorates. When an organism dies and the supply of carbon from the atmosphere ceases, the content of carbon-14 declines through radioactive decay at a fixed rate. In 1949 Willard Libby developed a method for applying this to determine the age of fossils and archeological relics.