Define radiocarbon dating
The method was developed by Willard Libby and his colleagues at the University of Chicago in 1949.
This means that although they are very similar chemically, they have different masses.The Conversation UK receives funding from Hefce, Hefcw, SAGE, SFC, RCUK, The Nuffield Foundation, The Ogden Trust, The Royal Society, The Wellcome Trust, Esmée Fairbairn Foundation and The Alliance for Useful Evidence, as well as sixty five university members.View the full list Radiocarbon dating has transformed our understanding of the past 50,000 years.All carbon atoms have a nucleus containing six protons.Ninety-nine percent of these also contain six neutrons.Carbon-13 and carbon-14 are thus isotopes of carbon-12.
Isotopes participate in the same chemical reactions but often at differing rates.
The total mass of the isotope is indicated by the numerical superscript.
While the lighter isotopes C has decayed that what remains can no longer be measured. In 5,730 years half of the C in the atmosphere, and therefore in plants and animals, has not always been constant.
The relatively short-lived C taken into organic matter is also slightly variable. However, under about 20,000 years the results can be compared with dendrochronology, based on tree rings.
For the most accurate work, variations are compensated by means of calibration curves.
Professor Willard Libby produced the first radiocarbon dates in 1949 and was later awarded the Nobel Prize for his efforts.