Radiocarbon dating calibration
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.
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.
In this way large domed tombs (known as tholos or beehive tombs) in Greece were thought to predate similar structures in the Scottish Island of Maeshowe.
This supported the idea that the classical worlds of Greece and Rome were at the centre of all innovations.
Radiocarbon dating works by comparing the three different isotopes of carbon.
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.
This method requires less than 1g of bone, but few countries can afford more than one or two AMSs, which cost more than A0,000.
Australia has two machines dedicated to radiocarbon analysis, and they are out of reach for much of the developing world.