Calibrated age dating
Then, the weight of the sample from its near-original state (i.e., when it was first fired) is subtracted from the heavier, hydroxyl-rich weight that it had when it was discovered.Given the rate of reabsorption determined through experimentation, the age of the fired clay can be calculated.Thus, the ratio of radiocarbon to stable carbon in a living plant is the same as the ratio of radiocarbon to stable carbon in the atmosphere at any given time.Animals (and humans) get their carbon atoms primarily from what they eat (i.e., plants).Part of the result of these collisions is the production of radiocarbon (C, pronounced "c fourteen"), carbon atoms which are chemically the same as stable carbon, but have two extra neutrons.Radiocarbon is not stable; over time radiocarbon atoms decay into nitrogen atoms.Radiocarbon dating works by precisely measuring the ratio of radiocarbon to stable carbon in a sample. The tree-ring chronologies have been constructed by counting the annual rings in living trees and matching patterns in these rings to older wood and dead trees.
This is because the amount and strength of cosmic radiation entering the earth's atmosphere has varied over time.
Thus the ratio of radiocarbon to stable carbon in living animal tissue is also virtually the same as the ratio of radiocarbon to stable carbon in the atmosphere at any given time.
This ratio is the same for all organisms across the globe at a given time due to the mixing of the atmosphere mentioned above.
However, variations in the established age of a fired pot are still possible, since the hydroxyl reabsorption rate is temperature-dependent.
Thus, some educated guesses about ancient weather conditions, especially the average temperature, are required for this technique, which the authors of the study termed “rehydroxylation dating.” In all, the dates the researchers had calculated match very well with samples that have known ages.