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Large sample sizes were needed for both counting methods, which limited their usefulness in such applications as studies of artwork, where only small samples could be taken.Accurate dating also had to wait for a good calibration of the radiocarbon time-scale in the 1960s, using an absolute chronology based on tree rings.Since nearly all applications where the precise age is needed require calibration, this difference is removed in the calibration process].Carbon-14 is produced in the upper atmosphere by nuclear reactions induced by cosmic rays on nitrogen (see Fig. Nearly all the carbon in the atmosphere is present as carbon dioxide (CO in the atmosphere maintains an equilibrium with the biosphere and the oceans.
This creates an error in the "raw" age of about 2 percent.The first attempt to use radiocarbon for dating was the work of Libby and his co-workers, 50 years ago, using counting of the decays of the radioactive isotope.In the 1950s, gas-counting methods were perfected, and later, liquid scintillation counting has also been used, as we will discuss later. What other documents or historical evidence are you going to use to help you understand the event or time in which this artifact was used? What does it tell you about technology at the time it was made? What did you find out from this artifact that you might not learn anywhere else?
What does this tell you about the people who made and used it?