Ams 14c dating

Renfrew (1973) called it 'the radiocarbon revolution' in describing its impact upon the human sciences.Oakley (1979) suggested its development meant an almost complete re-writing of the evolution and cultural emergence of the human species.

ams 14c dating-81

As 14C decays it emits a weak beta particle (b ), or electron, which possesses an average energy of 160ke V.

The decay can be shown: Thus, the 14C decays back to 14N.

They exist in equilibrium with the C14 concentration of the atmosphere, that is, the numbers of C14 atoms and non-radioactive carbon atoms stays approximately the same over time.

As soon as a plant or animal dies, they cease the metabolic function of carbon uptake; there is no replenishment of radioactive carbon, only decay.

The half-life () is the name given to this value which Libby measured at 556830 years. After 10 half-lives, there is a very small amount of radioactive carbon present in a sample.

At about 50 - 60 000 years, then, the limit of the technique is reached (beyond this time, other radiometric techniques must be used for dating).

The radiocarbon method was developed by a team of scientists led by the late Professor Willard F.

Libby of the University of Chicago in immediate post-WW2 years.

Desmond Clark (1979) wrote that were it not for radiocarbon dating, "we would still be foundering in a sea of imprecisions sometime bred of inspired guesswork but more often of imaginative speculation" (Clark, 1979:7).

Writing of the European Upper Palaeolithic, Movius (1960) concluded that "time alone is the lens that can throw it into focus".

There is a quantitative relationship between the decay of 14C and the production of a beta particle. That is, the probability of decay for an atom of 14C in a discrete sample is constant, thereby requiring the application of statistical methods for the analysis of counting data.

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