Carbon 14 dating used
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.However, more testing is needed to confirm that belief. 269, March 2012NCJ 237722 Philip Bulman is a writer and editor at NIJ.Danielle Mc Leod-Henning is a program manager and physical scientist at NIJ. Over the past six decades, the amount of radiocarbon in people or their remains depends heavily on when they were born or, more precisely, when their tissues were formed.Forensic anthropologists at The University of Arizona took advantage of this fact in a recent study funded by NIJ.
Adult teeth are formed at known intervals during childhood.
Thus, pupal case radiocarbon content would serve as a decay-resistant proxy for the tissues, yielding the year of death.
The spike in atmospheric carbon-14 levels during the 1950s and early 1960s makes this approach possible, but it also means it will have a limited period of utility because the amount of carbon-14 in the atmosphere is slowly returning to its natural level.
The researchers found that certain soft tissues — notably blood, nails and hair — had radiocarbon levels identical to the contemporary atmosphere.
Therefore, the radiocarbon level in those tissues post-mortem would indicate the year of death.
The new method is based on the fact that over the past 60 years, environmental levels of radiocarbon have been significantly perturbed by mid-20th-century episodes of above-ground nuclear weapons testing.