The rate of decay of N in 5,730 years (plus or minus 40 years).This is the “half-life.” So, in two half-lives, or 11,460 years, only one-quarter of that in living organisms at present, then it has a theoretical age of 11,460 years.It makes no sense at all if man appeared at the end of billions of years.

Obviously there will usually be a loss of stable carbon too but the proportion of radiocarbon to stable carbon will reduce according to the exponential decay law: R = A exp(-T/8033) where R is C ratio of the living organism and T is the amount of time that has passed since the death of the organism.

By measuring the ratio, R, in a sample we can then calculate the age of the sample: T = -8033 ln(R/A) Both of these complications are dealt with by calibration of the radiocarbon dates against material of known age.

Radiocarbon dating is one of the most widely used scientific dating methods in archaeology and environmental science.

It can be applied to most organic materials and spans dates from a few hundred years ago right back to about 50,000 years ago - about when modern humans were first entering Europe.

The use of various radioisotopes allows the dating of biological and geological samples with a high degree of accuracy.

However, radioisotope dating may not work so well in the future.

As explained below, the radiocarbon date tells us when the organism was alive (not when the material was used).

This fact should always be remembered when using radiocarbon dates.

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

Other useful radioisotopes for radioactive dating include Uranium -235 (half-life = 704 million years), Uranium -238 (half-life = 4.5 billion years), Thorium-232 (half-life = 14 billion years) and Rubidium-87 (half-life = 49 billion years).

Once an organism dies the carbon is no longer replaced.