Radiocarbon dating benefits
Measurement of radiocarbon was originally done by beta-counting devices, which counted the amount of beta radiation emitted by decaying atoms in the sample and not just the few that happen to decay during the measurements; it can therefore be used with much smaller samples (as small as individual plant seeds), and gives results much more quickly.
The development of radiocarbon dating has had a profound impact on archaeology.
This was possible because although annual plants, such as corn, have a concentrations in the neighbourhood of large cities are lower than the atmospheric average.
This fossil fuel effect (also known as the Suess effect, after Hans Suess, who first reported it in 1955) would only amount to a reduction of 0.2% in activity if the additional carbon from fossil fuels were distributed throughout the carbon exchange reservoir, but because of the long delay in mixing with the deep ocean, the actual effect is a 3% reduction.
Radiocarbon ages are still calculated using this half-life, and are known as "Conventional Radiocarbon Age".
Since the calibration curve (Int Cal) also reports past atmospheric concentration using this conventional age, any conventional ages calibrated against the Int Cal curve will produce a correct calibrated age.
In addition to permitting more accurate dating within archaeological sites than previous methods, it allows comparison of dates of events across great distances.
Histories of archaeology often refer to its impact as the "radiocarbon revolution".
To verify the accuracy of the method, several artefacts that were datable by other techniques were tested; the results of the testing were in reasonable agreement with the true ages of the objects.Additional complications come from the burning of fossil fuels such as coal and oil, and from the above-ground nuclear tests done in the 1950s and 1960s.Because the time it takes to convert biological materials to fossil fuels is substantially longer than the time it takes for its in the atmosphere, which attained a maximum in about 1965 of almost twice what it had been before the testing began.The ratio of λ is a constant that depends on the particular isotope; for a given isotope it is equal to the reciprocal of the mean-life – i.e.the average or expected time a given atom will survive before undergoing radioactive decay. The calculations involve several steps and include an intermediate value called the "radiocarbon age", which is the age in "radiocarbon years" of the sample: an age quoted in radiocarbon years means that no calibration curve has been used − the calculations for radiocarbon years assume that the atmospheric For consistency with these early papers, it was agreed at the 1962 Radiocarbon Conference in Cambridge (UK) to use the “Libby half-life” of 5568 years.