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Radiocarbon dates are presented in two ways because of this complication.The uncalibrated date is given with the unit BP (radiocarbon years before 1950).Radioactive decay can be used as a “clock” because it is unaffected by physical (e.g. For instance, the amount varies according to how many cosmic rays reach Earth.This is affected by solar activity and the earth’s magnetic field.
Radiocarbon dating has transformed our understanding of the past 50,000 years.The calibrated date is also presented, either in BC or AD or with the unit cal BP (calibrated before present - before 1950).The calibrated date is our “best estimate” of the sample’s actual age, but we need to be able to return to old dates and recalibrate them because new research is continually used to update the calibration curve.If 1% of the carbon in a 50,000 year old sample is from a modern contaminant, the sample will be dated to around 40,000 years.
Because of this, radiocarbon chemists are continually developing new methods to more effectively clean materials.Isotopes of a particular element have the same number of protons in their nucleus, but different numbers of neutrons.