The method was developed by Willard Libby in the late 1940s and soon became a standard tool for archaeologists.
Libby received the Nobel Prize for his work in 1960.
The argument may be compared to filling a barrel which has numerous small holes in its sides.
We stick the garden hose in and turn it on full blast.
The water coming out of the hose is analogous to the continuous production of carbon-14 atoms in the upper atmosphere.
The barrel represents the earth's atmosphere in which the carbon-14 accumulates.
As plants enter the human and animal food chains the C14 dioxide enters their living tissue.
The stable C12 and C13, and the unstable or radioactive Carbon 14. Only one C14 atom exists for every one trillion C12 atoms.
Nitrogen atoms in the upper atmosphere are struck by cosmic radiation and create C14 atoms.
Radiocarbon or C14 dating employs complex systems of measuring the unstable isotopes in once living matter.
There are three forms of carbon that naturally occur forming the building blocks of all plant and animal life.