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 Radiocarbon Revolution Since its development by Willard Libby in the 1940s, radiocarbon (14C) dating has become one of the most essential tools in archaeology.
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.
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.
There are two techniques for dating in archaeological sites: relative and absolute dating.