How carbon dating works

21 Apr

This is how carbon dating works: Carbon is a naturally abundant element found in the atmosphere, in the earth, in the oceans, and in every living creature.

C-12 is by far the most common isotope, while only about one in a trillion carbon atoms is C-14.

If either assumption is wrong carbon-14 dating doesn't work.

The first assumption is fairly reasonable, though some scientists have recently called into question whether or not nuclear decay rates were accelerated in the past (this might change the rate of carbon-14 decay).

When it comes to dating archaeological samples, several timescale problems arise.

C-14 is produced in the upper atmosphere when nitrogen-14 (N-14) is altered through the effects of cosmic radiation bombardment (a proton is displaced by a neutron effectively changing the nitrogen atom into a carbon isotope).

The new isotope is called "radiocarbon" because it is radioactive, though it is not dangerous.

The dating process is always designed to try to extract the carbon from a sample which is most representative of the original organism.

In general it is always better to date a properly identified single entity (such as a cereal grain or an identified bone) rather than a mixture of unidentified organic remains.