Radiocarbon decays slowly in a living organism, and the amount lost is continually replenished as long as the organism takes in air or food. Because carbon-14 decays at this constant rate, an estimate of the date at which an organism died can be made by measuring the amount of its residual radiocarbon.

How can carbon-14 date an artifact?

A special chemical is added to the sample that produces tiny specks of light called scintillations when carbon-14 atoms decay. A special detector called a spectrometer can see these specks and, with the aid of a computer program, can count them and determine the date of the sample.