Renfrew (1973) called it 'the radiocarbon revolution' in describing its impact upon the human sciences.

Nyerup's words illustrate poignantly the critical power and importance of dating; to order time.

Radiocarbon dating has been one of the most significant discoveries in 20th century science.

By measuring the C14 concentration or residual radioactivity of a sample whose age is not known, it is possible to obtain the countrate or number of decay events per gram of Carbon.

By comparing this with modern levels of activity (1890 wood corrected for decay to 1950 AD) and using the measured half-life it becomes possible to calculate a date for the death of the sample.

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.

The radiocarbon method was developed by a team of scientists led by the late Professor Willard F.

Libby of the University of Chicago in immediate post-WW2 years.

The radiocarbon method is based on the rate of decay of the radioactive or unstable carbon isotope 14 (14C), which is formed in the upper atmosphere through the effect of cosmic ray neutrons upon nitrogen 14.

The reaction is: (Where n is a neutron and p is a proton).

There is a useful diagrammatic representation of this process given here Libby, Anderson and Arnold (1949) were the first to measure the rate of this decay.