It has a radio half-life (T 1/2) of 5,730 years and is a low energy beta emitter with a radioactive range in air of ten inches.It is produced currently at a fairly constant rate in the upper atmosphere through the action of cosmic radiation on Nitrogen-14.
It is called “Carbon-12,” which is abbreviated “C.” The fact that the atom has six protons is what makes it carbon.
Greatly simplified, the process samples living and dead trees in a given area.
The tree-ring patterns are matched, and laid down in series, building a continuous timeline of known dates.
Methuselah Methuselah is a bristlecone pine, and the world's oldest living thing.
His growth rings document nearly 47 centuries of survival.