Among the best-known techniques are radiocarbon dating, potassium-argon dating and uranium-lead dating.
All ordinary matter is made up of combinations of chemical elements, each with its own atomic number, indicating the number of protons in the atomic nucleus.
The use of radiometric dating was first published in 1907 by Bertram Boltwood and is now the principal source of information about the absolute age of rocks and other geological features, including the age of fossilized life forms or the age of the Earth itself, and can also be used to date a wide range of natural and man-made materials.
By allowing the establishment of geological timescales, it provides a significant source of information about the ages of fossils and the deduced rates of evolutionary change.
The method compares the abundance of a naturally occurring radioactive isotope within the material to the abundance of its decay products, which form at a known constant rate of decay.Different methods of radiometric dating vary in the timescale over which they are accurate and the materials to which they can be applied.Additionally, elements may exist in different isotopes, with each isotope of an element differing in the number of neutrons in the nucleus.Research has been ongoing since the s to determine what the proportion of 14 C in the radioactive carbon dating equation has been over the past fifty thousand years.The resulting data, in the form of a calibration curve, is now used to convert a given measurement of radiocarbon in a sample into an estimate of the sample's calendar age.