Acuracy of carbon dating
This, in fact, is the most significant factor contributing to loss of precision in radiocarbon dates today.However, this contribution is usually only a few decades.
Calibration of radiocarbon results is needed to account for changes in the atmospheric concentration of carbon-14 over time.
These changes were brought about by several factors including, but not limited to, fluctuations in the earth’s geomagnetic moment, fossil fuel burning, and nuclear testing.
In Accelerator Mass Spectrometry (AMS), for example, the number of radiocarbon atoms in a stream of atoms coming from the sample is counted.
Thus there are statistical counting uncertainties proportional to the square root of the number of atoms counted.
Carbon consists of 99% carbon-12, 1% carbon-13, and about one part per million carbon-14.
Results of carbon-14 dating are reported in radiocarbon years, and calibration is needed to convert radiocarbon years into calendar years.
Although it is less accurate, the Libby half-life was retained to avoid inconsistencies or errors when comparing carbon-14 test results that were produced before and after the Cambridge half-life was derived.
Radiocarbon measurements are based on the assumption that atmospheric carbon-14 concentration has remained constant as it was in 1950 and that the half-life of carbon-14 is 5568 years.
Modern accelerator mass spectrometry (used for radiocarbon dating purposes to separate radiocarbon atoms from stable carbon atoms and count them) is quite precise.
The technology involved is fascinating and impressive.
Modern radiocarbon dating uses tree-ring chronologies to produce the calibration curve.Tags: Adult Dating, affair dating, sex dating