Two scientists from the University of California Radiation Laboratory discovered carbon-14, a new isotope of carbon.
While the existence of carbon-14 had previously been suggested in 1934, it was only in 1940 that Martin Kamen and Sam Ruben proved it. This discovery was pretty extraordinary, as we’re able to determine the age of organic materials by looking at the amount of carbon-14 in them – otherwise known as radiocarbon dating.