How is radiocarbon dating used
Three isotopes of carbon are found in nature; carbon-12, carbon-13 and carbon-14.
Carbon-12 accounts for ~99.8 % of all carbon atoms, carbon-13 accounts for ~1% of carbon atoms while ~1 in every 1 billion carbon atoms is carbon-14.
Hereafter these isotopes will be referred to as 12C, 13C, and 14C.
14C is radioactive and has a half-life of 5730 years.
The half-life is the time taken for an amount of a radioactive isotope to decay to half its original value.
Because this decay is constant it can be used as a “clock” to measure elapsed time assuming the starting amount is known.
The History of Radiocarbon Dating Willard Libby invented radiocarbon dating in the late 1940s.
His first publication showed the comparisons between known age samples and radiocarbon age (Libby et al, 1949; Libby, 1952). For the first time it was possible to obtain ages for many events which occurred over the past ~50,000 years.