Carbon dating technique
In 2008 we could only calibrate radiocarbon dates until 26,000 years.
Now the curve extends (tentatively) to 50,000 years.
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.
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.
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.
Australian National University provides funding as a member of The Conversation AU.