The method was developed by Willard Libby in the late 1940s and soon became a standard tool for archaeologists.Libby received the Nobel Prize in Chemistry for his work in 1960.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.Other useful radioisotopes for radioactive dating include Uranium -235 (half-life = 704 million years), Uranium -238 (half-life = 4.5 billion years), Thorium-232 (half-life = 14 billion years) and Rubidium-87 (half-life = 49 billion years).The use of various radioisotopes allows the dating of biological and geological samples with a high degree of accuracy.Rachel Wood does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond the academic appointment above.Australian National University provides funding as a member of The Conversation AU.
Potassium-40 is another radioactive element naturally found in your body and has a half-life of 1.3 billion years.
Research has been ongoing since the 1960s to determine what the proportion of in the atmosphere has been over the past fifty thousand years.
The resulting data, in the form of a calibration curve, is now used to convert a given measurement of radiocarbon in a sample into an estimate of the sample's calendar age.
The carbon-14 decays with its half-life of 5,700 years, while the amount of carbon-12 remains constant in the sample.
By looking at the ratio of carbon-12 to carbon-14 in the sample and comparing it to the ratio in a living organism, it is possible to determine the age of a formerly living thing fairly precisely. So, if you had a fossil that had 10 percent carbon-14 compared to a living sample, then that fossil would be: t = [ ln (0.10) / (-0.693) ] x 5,700 years t = [ (-2.303) / (-0.693) ] x 5,700 years t = [ 3.323 ] x 5,700 years Because the half-life of carbon-14 is 5,700 years, it is only reliable for dating objects up to about 60,000 years old.