14c dating soil
It is the supposed accuracy of the new method that allows measurements sensitive enough to date objects claimed to be more than twenty or thirty thousand years old.
A recent test by the British Science and Engineering Research Council has shown that the accuracy of the new technique is greatly overrated.
This limit is currently accepted by nearly all radiocarbon dating practitioners.
It follows that the older a date is, even within this 'limit', the greater are the doubts about the date's accuracy.
PROBLEMS WITH RADIOCARBON DATING During the last 30 years, a new method of determining C14/C12 ratios has been developed.
It uses accelerator mass spectrometry to determine the amounts of C14 and C12 in a small sample which is vaporised in the test.
However, because it has too many neutrons for the number of protons it contains, it is not a stable atom.
Every 5,730 years, approximately half of this radioactive carbon spontaneously converts itself back into nitrogen by emitting an electron from a neutron.
As the number of protons decides the chemical nature of an atom, the atom now behaves like a carbon atom.Radioactive carbon (Carbon 14) is formed in the upper atmosphere as a byproduct of cosmic radiation.