# Carbon dating calculation

At any particular time all living organisms have approximately the same ratio of carbon 12 to carbon 14 in their tissues.

When an organism dies it ceases to replenish carbon in its tissues and the decay of carbon 14 to nitrogen 14 changes the ratio of carbon 12 to carbon 14.

This half life is a relatively small number, which means that carbon 14 dating is not particularly helpful for very recent deaths and deaths more than 50,000 years ago.

After 5,730 years, the amount of carbon 14 left in the body is half of the original amount.

Carbon-14 dating can be used on objects ranging from a few hundred years old to 50,000 years old.

Libby and others (University of Chicago) devised a method of estimating the age of organic material based on the decay rate of carbon-14.

Potassium-40 is another radioactive element naturally found in your body and has a half-life of 1.3 billion years.

Where t is the age of the fossil (or the date of death) and ln() is the natural logarithm function.The half-life of a radioactive isotope describes the amount of time that it takes half of the isotope in a sample to decay.In the case of radiocarbon dating, the half-life of carbon 14 is 5,730 years.Because of the fossil fuel effect, this is not actually the activity level of wood from 1950; the activity would have been somewhat lower.The fossil fuel effect was eliminated from the standard value by measuring wood from 1890, and using the radioactive decay equations to determine what the activity would have been at the year of growth.