The method was developed by Willard Libby in the late s and soon became a standard tool for archaeologists. Libby received the Nobel Prize in Chemistry for his work in The radiocarbon dating method is based on the fact that radiocarbon is constantly being created in the atmosphere by the interaction of cosmic rays with atmospheric nitrogen. The resulting radiocarbon combines with atmospheric oxygen to form radioactive carbon dioxidewhich is incorporated into plants by photosynthesis ; animals then acquire 14 C by eating the plants.
When the animal or free tattoo dating dies, it stops exchanging carbon with its environment, and from that point onwards the amount of 14 C it contains begins to decrease as the 14 C undergoes radioactive decay. Measuring the amount of 14 C in a sample from a dead plant or animal such as a piece of wood or a fragment of bone provides information that can be used to calculate when the animal or plant died. The older a sample is, the less 14 C there is to be detected, and because the half-life of 14 C the period of time after which half of a given sample will have decayed is about 5, years, the oldest dates that can be reliably measured by this process date to around 50, years ago, although special preparation methods occasionally permit accurate analysis of older samples.
The idea behind radiocarbon dating is straightforward, but years of work were required to develop the technique to the point where accurate dates could be obtained.
Research has been ongoing since the s to determine what the proportion of 14 C in the atmosphere has been over the past fifty thousand years.
English in North America. The State of the LanguageвEnglish Observed. The Oxford Free tattoo dating Dictionary: Similarly, loover was respelled in the 17th century by influence of the unrelated Louvre. See OEDs. Webster's third new international dictionary of the English language. The New York Times Arts section. The New York Times Company.
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