Radiocarbon dating is a technique for determining the age of very old objects consisting of organic (carbon-based) materials, such as wood, paper, cloth, and bone. The technique is based on the fact that both stable and radioactive isotopes of carbon exist. These isotopes behave almost identically in biological, chemical, and physical processes.

Carbon-12, a stable isotope, makes up about 99% of all carbon found in nature. Radioactive carbon-14 is formed in the atmosphere when neutrons produced in cosmic ray showers react with nitrogen atoms.

Despite the fact that it makes up no more than 0.08% of the earth's crust, carbon is an exceedingly important element. It occurs in all living materials and is found in many important rocks and minerals, including limestone and marble, as well as in carbon dioxide. Carbon moves through the atmosphere, hydrosphere, lithosphere, and biosphere in a series of reactions known as the carbon...