The results provide conclusive evidence that the linen of the Shroud of Turin is mediaeval.
The Shroud of Turin , which many people believe was used to wrap Christ's body, bears detailed front and back images of a man who appears to have suffered whipping and crucifixion.
The method was developed by Willard Libby in the late 1940s and soon became a standard tool for archaeologists.
Libby received the Nobel Prize in Chemistry for his work in 1960.
This tendency to decay, called radioactivity, is what gives radiocarbon the name radiocarbon.
The atmosphere contains many stable carbon atoms and relatively few radiocarbon atoms.
Ninety-nine percent of these also contain six neutrons.
The size of the sample then required, however, was ~500cm, which would clearly have resulted in an unacceptable amount of damage, and it was not until the development in the 1970s of small gas-counters and accelerator-mass-spectrometry techniques (AMS), requiring samples of only a few square centimetres, that radiocarbon dating of the shroud became a real possibility. The shroud was separated from the backing cloth along its bottom left-hand edge and a strip (~10 mm x 70 mm) was cut from just above the place where a sample was previously removed in 1973 for examination.
Part of the result of these collisions is the production of radiocarbon (C, pronounced "c fourteen"), carbon atoms which are chemically the same as stable carbon, but have two extra neutrons.
Radiocarbon is not stable; over time radiocarbon atoms decay into nitrogen atoms.
They have masses of 13 and 14 respectively and are referred to as "carbon-13" and "carbon-14." If two atoms have equal numbers of protons but differing numbers of neutrons, one is said to be an "isotope" of the other.
Carbon-13 and carbon-14 are thus isotopes of carbon-12.