Uses radioisotopes carbon 14 dating
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.Materials that originally came from living things, such as wood and natural fibres, can be dated by measuring the amount of carbon-14 they contain.For example, in 1991, two hikers discovered a mummified man, preserved for centuries in the ice on an alpine mountain.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.The approximate time since the organism died can be worked out by measuring the amount of carbon-14 left in its remains compared to the amount in living organisms.The attributes of naturally decaying atoms, known as radioisotopes, give rise to their multiple applications across many aspects of modern day life (see also information paper on The Many Uses of Nuclear Technology).
A child mummy is found high in the Andes and the archaeologist says the child lived more than 2,000 years ago.
The amount of carbon-14 in the air has stayed the same for thousands of years.
There is a small amount of radioactive carbon-14 in all living organisms because it enters the food chain.
Once an organism dies, it stops taking in carbon-14.
The carbon-14 it contained at the time of death decays over a long period of time, and the radioactivity of the material decreases.