Noong 1940s, nadiskubre ni Willard Libby na ang carbon-14 ay nagdedecay sa isang constant rate.Pumapasok sa mundo ang mga cosmic rays at tinatamaan ang lahat ng bagay (kabilang na tayo! Kapag nagcollide ang mga cosmic rays na ito sa mga nagkalat na atom, lumilikha ito ng mga energy neutrons.
Kapag namatay ang isang organismo, hindi na ito makakaabsorb pa ng Carbon.
He was inspired by physicist Serge Korff (1906–1989) of New York University, who in 1939 discovered that neutrons were produced during the bombardment of the atmosphere by cosmic rays.
Korff predicted that the reaction between these neutrons and nitrogen-14, which predominates in the atmosphere, would produce carbon-14, also called radiocarbon.
The “radiocarbon revolution” made possible by Libby’s discovery greatly benefitted the fields of archaeology and geology by allowing practitioners to develop more precise historical chronologies across geography and cultures.
Willard Libby (1908–1980), a professor of chemistry at the University of Chicago, began the research that led him to radiocarbon dating in 1945.