The C14 Method (Radiocarbon Dating)
Developed by W.F. Libby in 1946–47, the carbon-14 method is the best known means of dating organic material.
The tissue of every organism absorbs the C14 isotope from the atmosphere. When the organism dies, the flow of C14 is interrupted and any C14 absorbed during its life gradually disappears – half of it every 5730 years (the half-life of the isotope). The amount of remaining C14 can be measured using a mass spectrometer, and from this it is possible to calculate how long ago the organism lived.