What is carbon dating?

Radiocarbon dating, developed by Willard Libby in the late 1940s, is a technique for finding the age of organic remains such as wood, bone, and cloth. Living things constantly take in carbon from the atmosphere, including a small, steady proportion of the radioactive isotope carbon-14. When an organism dies, it stops absorbing carbon, and the carbon-14 it contains begins to decay into nitrogen at a fixed rate, with a half-life of about 5,730 years. By measuring how much carbon-14 is left compared with stable carbon, scientists can calculate how long ago the organism died. The method is reliable for objects up to roughly 50,000 years old, after which too little carbon-14 remains to measure. Carbon dating revolutionised archaeology and earned Libby the Nobel Prize in Chemistry in 1960.