Fallout from atmospheric testing of nuclear weapons has distorted the background levels of the radioactive isotope carbon-14, used by archaeologists to date organic materials

But it has an upside, providing a new scale by which to date more recent events, helping researchers track cell turnover in different parts of the body and in testing the age of everything from vintage wine to elephant ivory.

Curt Stager and Martha Foley discuss radiocarbon dating.

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