Thus the ratio of radiocarbon to stable carbon in living animal tissue is also virtually the same as the ratio of radiocarbon to stable carbon in the atmosphere at any given time.This ratio is the same for all organisms across the globe at a given time due to the mixing of the atmosphere mentioned above.When an organism dies (whether plant or animal) its intake of carbon atoms ceases.The starting ratio of radiocarbon to stable carbon is locked in at that point. The purpose in each of these methods is to determine the ratio of radiocarbon to stable carbon in the sample.
It can be used on objects as old as about 62,000 years. Atoms of the same element that have different numbers of neutrons are called isotopes. Most carbon on Earth exists as the very stable isotope carbon-12, with a very small amount as carbon-13.
The following article is primarily based on a discussion of radiocarbon dating found in The Biblical Chronologist Volume 5, Number 1. Radiocarbon dating is based on a few relatively simple principles. The vast majority of these are C (pronounced "c twelve"), the stable isotope of carbon.
However, cosmic radiation constantly collides with atoms in the upper atmosphere.
The ratio of radiocarbon to stable carbon atoms in the atmosphere has varied in the past.
This is because the amount and strength of cosmic radiation entering the earth's atmosphere has varied over time.