Radiocarbon dating

Radiocarbon dating is a method that provides objective age estimates for carbon-based materials that originated from living organisms. 1 An age could be estimated by measuring the amount of Carbon-14 present in the sample and comparing this against an internationally used reference standard.

The impact of the radiocarbon dating technique on modern man has made it one of the most significant discoveries of the 20th century. No other scientific method has managed to revolutionize man’s understanding not only of his present but also of events that already happened thousands of years ago. Archaeology and other human sciences use radiocarbon dating to prove or disprove theories. Over the years, Carbon 14 dating has also found applications in geology, hydrology, geophysics, atmospheric science, oceanography, paleoclimatology and even biomedicine.

Radiocarbon (Carbon 14) is an isotope of the element carbon that is unstable and weakly radioactive. The stable isotopes are Carbon 12 and Carbon 13.

Carbon 14 is continually being formed in the upper atmosphere by the effect of cosmic ray neutrons on nitrogen 14 atoms. It is rapidly oxidized in air to form Carbon dioxide and enters the global carbon cycle.

Plants and animals assimilate Carbon 14 from carbon dioxide throughout their lifetimes. When they die, they stop exchanging carbon with the biosphere and their Carbon 14 content then starts to decrease at a rate determined by the law of radioactive decay.

Radiocarbon dating is essentially a method designed to measure residual radioactivity.