C 14 carbon dating
Obviously, this works only for things which were once living.It cannot be used to date volcanic rocks, for example.The rate of decay of N in 5,730 years (plus or minus 40 years).This is the “half-life.” So, in two half-lives, or 11,460 years, only one-quarter of that in living organisms at present, then it has a theoretical age of 11,460 years.
Anything over about 50,000 years old, should theoretically have no detectable C.
That is, they take up less than would be expected and so they test older than they really are.
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