That is, samples with dates known from historical records can be used to check the accuracy of the method.
Despite this, however, caution is still necessary in accepting dates derived from carbon dating.
It takes another 5,730 for half of the remainder to decay, and then another 5,730 for half of what's left then to decay and so on.
It is naturally unstable and so it will spontaneously decay back into N-14 after a period of time.It takes about 5,730 years for half of a sample of radiocarbon to decay back into nitrogen. This is how carbon dating works: Carbon is a naturally abundant element found in the atmosphere, in the earth, in the oceans, and in every living creature.C-12 is by far the most common isotope, while only about one in a trillion carbon atoms is C-14.However, this prompts the question of how one might determine this prior to using carbon dating to determine the age.
They further argue that dating much older items will result in anomalous dates, which might fall within the range that carbon dating can measure. However, as explained above, carbon dating is incapable of providing dates in the range of millions or billions of years, and many scientists turn to other forms of dating to derive such extremely long time periods.Some also argue that carbon dating should only be used on samples that fall within the range over which it can measure.So, if we find the remains of a dead creature whose C-12 to C-14 ratio is half of what it's supposed to be (that is, one C-14 atom for every two trillion C-12 atoms instead of one in every trillion) we can assume the creature has been dead for about 5,730 years (since half of the radiocarbon is missing, it takes about 5,730 years for half of it to decay back into nitrogen).If the ratio is a quarter of what it should be (one in every four trillion) we can assume the creature has been dead for 11,460 year (two half-lives).Plants and animals naturally incorporate both the abundant C-12 isotope and the much rarer radiocarbon isotope into their tissues in about the same proportions as the two occur in the atmosphere during their lifetimes.