However, radioisotope dating may not work so well in the future.
Anything that dies after the 1940s, when Nuclear bombs, nuclear reactors and open-air nuclear tests started changing things, will be harder to date precisely.
As soon as a living organism dies, it stops taking in new carbon.
The ratio of carbon-12 to carbon-14 at the moment of death is the same as every other living thing, but the carbon-14 decays and is not replaced.
As soon as it dies, however, the C ration gets smaller.
In other words, we have a ‘clock’ which starts ticking at the moment something dies.
The half-life of a radioactive isotope describes the amount of time that it takes half of the isotope in a sample to decay.
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.
Experts can compare the ratio of carbon 12 to carbon 14 in dead material to the ratio when the organism was alive to estimate the date of its death.
by Dr Carl Wieland An attempt to explain this very important method of dating and the way in which, when fully understood, it supports a ‘short’ timescale.
In fact, the whole method is a giant ‘clock’ which seems to put a very young upper limit on the age of the atmosphere.