The American chemist Willard Frank Libby (1908-1980) pioneered in radiocarbon dating, for which he received the Nobel Prize.

Willard Libby, a farmer's son, was born on December 17, 1908, at Grand Valley, Colorado. After schooling near Sebastopol, California, he entered the University of California at Berkeley, graduating in 1931, earning his doctorate in 1933, and teaching physical chemistry there until World War II.

Libby's most notable achievement, the method of radiocarbon dating, stemmed from the 1939 discovery that cosmic rays at about 10 miles' altitude interacted with air to give a relatively high density of neutrons. This implied rapid formation of radiocarbon by neutron capture by the abundant nitrogen isotope. Radiocarbon has a long halflife (about 5,730 years), decaying into nitrogen. It may be assumed that after many thousands of years its rate of formation equals its rate of disintegration. If it is rapidly oxidized to carbon dioxide and this enters the biosphere, all living...