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.
Scientists at Brookhaven National Laboratory and the Physikalish-Technische-Bundesandstalt in Germany have reported "unexplained periodic fluctuations in the [nuclear] decay rates of Si-32 and Ra-226...
strongly correlated in time, not only with each other, but also with the distance between the Earth and the Sun." It is likely that similar discrepancies and fluctuations occur with other nuclear decay rates, such as that of Many people believe that carbon dating has proved that the Earth is millions or billions of years old, much older than the biblically derived date of around 6,000 years.
It is naturally unstable and so it will spontaneously decay back into N-14 after a period of time.
It takes about 5,730 years for half of a sample of radiocarbon to decay back into nitrogen.
Plants and animals naturally incorporate both the abundant C-12 isotope and the much rarer radiocarbon isotope into their tissues in about the same proportions as the two occur in the atmosphere during their lifetimes.
When a creature dies, it ceases to consume more radiocarbon while the C-14 already in its body continues to decay back into nitrogen.
...various plants have differing abilities to exclude significant proportions of the C-14 in their intake. The varying rates at which C-14 is excluded in plants also means that the apparent age of a living animal may be affected by an animal's diet.
That is, samples with dates known from historical records can be used to check the accuracy of the method.
Despite this, however, caution is still necessary in accepting dates derived from carbon dating.
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.
First of all, it's predicated upon a set of questionable assumptions.