By measuring the ratio of carbon-12 to carbon-14 in the sample and comparing it to the ratio in a living organism, it is possible to determine the age of the artifact.Of practical importance to a wide range of scientific disciplines is the radiocarbon calibration, which is used for converting radiocarbon ages to calendar years; essential for measuring time and rates of change for numerous scientific fields.The carbon-14 atoms combine with oxygen to form carbon dioxide, which plants absorb naturally and incorporate into plant fibers by photosynthesis.
This dramatic increase in the number of radiocarbon dates is driving the demand for a radiocarbon calibration program that spans the entire radiocarbon timescale from the present to 55,000 years BP.
Extension of the C record beyond the 0 to 11,900 year long tree ring record is well underway, being measured in many different archives, and undoubtedly an enormous amount of scientific knowledge will stem from these studies.
Our calibration has the advantage that each data point in the calibration has a measured calendar age (U) and radiocarbon age with know errors that are independent from each other.
In a series of published papers and manuscripts soon to be published, we present our analytical techniques in detail (Mortlock et al., 2005; Chiu et al., 2005a) and the geochemical (Cao et al., 2005) and geophysical (Chiu et al., 2005b, 2005c) explanations for the departure of radiocarbon dates from the true calendar ages and compare our results to other radiocarbon calibration data.
When these energetic neutrons collide with a nitrogen-14 (seven protons, seven neutrons) atom it turns into a carbon-14 atom (six protons, eight neutrons) and a hydrogen atom (one proton, zero neutrons).