A chemist worked out how to read the age of anything that was once alive

Willard Libby showed in 1949 that living things absorb radioactive carbon-14 at a steady rate while alive, and that it then decays at a known pace after death. Measuring how much carbon-14 remains in bone, wood or cloth lets scientists date organic remains up to roughly 50,000 years old, transforming archaeology and palaeontology overnight. Libby won the 1960 Nobel Prize in Chemistry for the method.

— Willard Libby, Radiocarbon Dating — University of Chicago Press, 1949; Nobel Prize in Chemistry, 1960