Wiki carbon dating
The radioactive decay of carbon-14 follows an exponential decay.A quantity is said to be subject to exponential decay if it decreases at a rate proportional to its value.Carbon-14 has a half-life of 5730 years, meaning that the amount of carbon-14 in a sample is halved over the course of 5730 years due to radioactive decay.Carbon-14 would have long ago vanished from Earth were it not for the unremitting cosmic ray impacts on nitrogen in the Earth's atmosphere, which create more of the isotope.
Libby estimated that the steady state radioactivity concentration of exchangeable carbon-14 would be about 14 disintegrations per minute (dpm) per gram.
These raw dates are also based on a slightly-off historic value for the radiocarbon half-life.
Such value is used for consistency with earlier published dates (see "Radiocarbon half-life" below).
Note: Many of our articles have direct quotes from sources you can cite, within the Wikipedia article! One of the most frequent uses of radiocarbon dating is to estimate the age of organic remains from archaeological sites.
Such raw ages can be calibrated to give calendar dates.