Other high profile projects include the dating of the Turin Shroud to the medieval period, the dating of the Dead Sea Scrolls to around the time of Christ, and the somewhat controversial dating of the spectacular rock art at Chauvet Cave to c.38,000 cal BP (c.32,000 BP) – thousands of years earlier than expected.
The second difficulty arises from the extremely low abundance of C, making it incredibly difficult to measure and extremely sensitive to contamination.
In the early years of radiocarbon dating a product’s decay was measured, but this required huge samples (e.g. Many labs now use an Accelerator Mass Spectrometer (AMS), a machine that can detect and measure the presence of different isotopes, to count the individual C atoms in a sample.
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.
Isotopes of a particular element have the same number of protons in their nucleus, but different numbers of neutrons.
This means that although they are very similar chemically, they have different masses.Some of the first radiocarbon dates produced showed that the Scottish tombs were thousands of years older than those in Greece.The barbarians of the north were capable of designing complex structures similar to those in the classical world.Radiocarbon dates are presented in two ways because of this complication.The uncalibrated date is given with the unit BP (radiocarbon years before 1950).Rachel Wood does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.