Carbon 14 dating on
Renfrew (1973) called it 'the radiocarbon revolution' in describing its impact upon the human sciences.
Oakley (1979) suggested its development meant an almost complete re-writing of the evolution and cultural emergence of the human species.
These isotopes are present in the following amounts C12 - 98.89%, C13 - 1.11% and C14 - 0.00000000010%.
Thus, one carbon 14 atom exists in nature for every 1,000,000,000,000 C12 atoms in living material.
As 14C decays it emits a weak beta particle (b ), or electron, which possesses an average energy of 160ke V.
The decay can be shown: Thus, the 14C decays back to 14N.
The half-life () is the name given to this value which Libby measured at 556830 years. After 10 half-lives, there is a very small amount of radioactive carbon present in a sample.
At about 50 - 60 000 years, then, the limit of the technique is reached (beyond this time, other radiometric techniques must be used for dating).
Plants and animals which utilise carbon in biological foodchains take up 14C during their lifetimes.
Libby later received the Nobel Prize in Chemistry in 1960: (From Taylor, 1987).
Today, there are over 130 radiocarbon dating laboratories around the world producing radiocarbon assays for the scientific community.
Herein lies the true advantage of the radiocarbon method, it is able to be uniformly applied throughout the world.
Included below is an impressive list of some of the types of carbonaceous samples that have been commonly radiocarbon dated in the years since the inception of the method: The historical perspective on the development of radiocarbon dating is well outlined in Taylor's (1987) book "Radiocarbon Dating: An archaeological perspective".
The C14 technique has been and continues to be applied and used in many, many different fields including hydrology, atmospheric science, oceanography, geology, palaeoclimatology, archaeology and biomedicine.