For the most accurate work, variations are compensated by means of calibration curves.The method was developed by Willard Libby and his colleagues at the University of Chicago in 1949.But as the method was refined, it started to show rather regular anomalies.
In contrast to relative dating techniques whereby artifacts were simply designated as "older" or "younger" than other cultural remains based on the presence of fossils or stratigraphic position, 14C dating provided an easy and increasingly accessible way for archaeologists to construct chronologies of human behavior and examine temporal changes through time at a finer scale than what had previously been possible.
The application of Accelerator Mass Spectrometry (AMS) for radiocarbon dating in the late 1970s was also a major achievement.
Carbon dioxide is distributed on a worldwide basis into various atmospheric, biospheric, and hydrospheric reservoirs on a time scale much shorter than its half-life.
Measurements have shown that in recent history, radiocarbon levels have remained relatively constant in most of the biosphere due to the metabolic processes in living organisms and the relatively rapid turnover of carbonates in surface ocean waters.
The method was developed immediately following World War II by Willard F.
Libby and coworkers and has provided age determinations in archeology, geology, geophysics, and other branches of science.
Offering in 1952 his new radiocarbon method for calculating the age of organic material (the time interval since the plant or the animal died), W. Libby clearly saw the limitations of the method and the conditions under which his theoretical figures would be valid: A.
Of the three reservoirs of radiocarbon on earththe atmosphere, the biosphere, and the hydrosphere, the richest is the lastthe oceans with the seas.
Desmond Clark (1979:7) observed that without radiocarbon dating "we would still be foundering in a sea of imprecisions sometime bred of inspired guesswork but more often of imaginative speculation." And as Colin Renfrew (1973) aptly noted over 30 years ago, the "Radiocarbon Revolution" transformed how archaeologists could interpret the past and track cultural changes through a period in human history where we see among other things the massive migration of peoples settling virtually every major region of the world, the transition from hunting and gathering to more intensive forms of food production, and the rise of city-states.
However, as with any dating technique there are limits to the kinds of things that can be satisfactorily dated, levels of precision and accuracy, age range constraints, and different levels of susceptibility to contamination.
Radio carbon dating determines the age of ancient objects by means of measuring the amount of carbon-14 there is left in an object.