Nitrogen dating archaeology
In the 19th and early 20th century incredibly patient and careful archaeologists would link pottery and stone tools in different geographical areas by similarities in shape and patterning.
Then, by using the idea that the styles of objects evolve, becoming increasing elaborate over time, they could place them in order relative to each other - a technique called seriation.
In addition, samples need to be thoroughly cleaned to remove carbon contamination from glues and soil before dating.
This is particularly important for very old samples.
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.
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.
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.