14c dating method
One rare form has atoms that are 14 times as heavy as hydrogen atoms: carbon-14, or C ratio gets smaller.
So, we have a “clock” which starts ticking the moment something dies.
Radiocarbon dating is a valuable tool to chronologists and archaeologists.
It provides an objective, absolute method of determining a sample's age with quantifiable precision.
(This, in turn, is caused by variations in the magnetic fields of the earth and sun, for example.) Although the ratio of radiocarbon to stable carbon in the atmosphere has varied over time, it is quite uniform around the globe at any given time because the atmosphere mixes very quickly and constantly.
Plants obtain all their carbon atoms from the atmosphere.
Part of the result of these collisions is the production of radiocarbon (C, pronounced "c fourteen"), carbon atoms which are chemically the same as stable carbon, but have two extra neutrons.
Radiocarbon is not stable; over time radiocarbon atoms decay into nitrogen atoms.
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.
The raw radiocarbon date of any sample can then be converted to true date by using this calibration table.
This calibration step eliminates any concern about fluctuations in historic radiocarbon to stable carbon ratios or decay rates.
The ratio of radiocarbon to stable carbon atoms in the atmosphere has varied in the past.
This is because the amount and strength of cosmic radiation entering the earth's atmosphere has varied over time.It makes no sense at all if man appeared at the end of billions of years.