Carbon 12 and carbon 14 dating
Radio carbon dating determines the age of ancient objects by means of measuring the amount of carbon-14 there is left in an object.A man called Willard F Libby pioneered it at the University of Chicago in the 50's. This is now the most widely used method of age estimation in the field of archaeology.Plants get their share of carbon atoms from the atmosphere. It is seen that at any given point of time, the ratio of stable carbon and radiocarbon in the atmosphere, is almost same as the ratio of stable carbon and radiocarbon in living organisms like plants, animals, and humans.When a living organism dies, its carbon intake ceases.
Above is a graph that illustrates the relationship between how much Carbon 14 is left in a sample and how old it is.
By comparing age of a sample deduced by using carbon-14 dating to results from other dating techniques, discrepancies have been noticed.► With the advancement of nuclear reactors and weapons, it is possible that the amount of carbon-14 has changed in the recent years, specially carbon data from the 1950s and 1960s are questionable.
There is also the likelihood of the sample being contaminated with old or new carbon.
There are calibration charts as well to account for the change in the amount of carbon-14 content in the atmosphere over the years to diminish errors.
Although carbon-14 dating technique has its limitations, still it is a very helpful tool for archaeologists.