One chemist's measurement of radioactive decay let archaeologists date anything organic

Willard Libby realised in the late 1940s that living things absorb a tiny, steady proportion of radioactive carbon-14 from the atmosphere, which then decays at a known rate after death. By measuring how much carbon-14 remains in bone, wood, or cloth, scientists can date it to within a few decades for objects up to about 50,000 years old. Libby won the 1960 Nobel Prize in Chemistry for the method.

— Willard F. Libby, Radiocarbon Dating — University of Chicago Press, 1955