Dating techniques in archaeology
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.
American Chemical Society National Historic Chemical Landmarks.
Discovery of Radiocarbon Dating (accessed October 31, 2017). Sheridan Bowman, Radiocarbon Dating: Interpreting the Past (1990), University of California Press Accelerator Mass Spectrometry Radiocarbon Dating Calibration of Carbon 14 Dating Results Radiocarbon Dating and Bomb Carbon About AMS Dating Accelerator Mass Spectrometry (AMS) dating involves accelerating ions to extraordinarily high kinetic energies followed by mass analysis.
Liquid scintillation counting is another radiocarbon dating technique that was popular in the 1960s.
In this method, the carbon 14 content is directly measured relative to the carbon 12 and carbon 13 present. Some inorganic matter, like a shell’s aragonite component, can also be dated as long as the mineral’s formation involved assimilation of carbon 14 in equilibrium with the atmosphere.
American physical chemist Willard Libby led a team of scientists in the post World War II era to develop a method that measures radiocarbon activity.
He is credited to be the first scientist to suggest that the unstable carbon isotope called radiocarbon or carbon 14 might exist in living matter. Libby and his team of scientists were able to publish a paper summarizing the first detection of radiocarbon in an organic sample. Libby who first measured radiocarbon’s rate of decay and established 5568 years ± 30 years as the half-life. Libby was awarded the Nobel Prize in Chemistry in recognition of his efforts to develop radiocarbon dating.1.
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.
The radiocarbon age of a certain sample of unknown age can be determined by measuring its carbon 14 content and comparing the result to the carbon 14 activity in modern and background samples.