Carbon dating is
Historians can tell what cultures thrived in different regions and when they disintegrated.Anthropologists can describe a people’s physical character, culture, and environmental and social relations.As a rule, carbon dates are younger than calendar dates: a bone carbon-dated to 10,000 years is around 11,000 years old, and 20,000 carbon years roughly equates to 24,000 calendar years.The problem, says Bronk Ramsey, is that tree rings provide a direct record that only goes as far back as about 14,000 years.
But even he “realized that there probably would be variation”, says Christopher Bronk Ramsey, a geochronologist at the University of Oxford, UK, who led the latest work, published today in Science.Carbon 14 dating remains to be a powerful, dependable, and widely applicable technique that is invaluable to archaeologists and other scientists.The unstable and radioactive carbon 14, called radiocarbon, is a naturally occurring isotope of the element carbon.“If you have a better estimate of when the last Neanderthals lived to compare to climate records in Greenland or elsewhere, then you’ll have a better idea of whether the extinction was climate driven or competition with modern humans,” says Paula Reimer, a geochronologist at Queen’s University in Belfast, UK.
She will lead efforts to combine the Lake Suigetsu measurements with marine and cave records to come up with a new standard for carbon dating.
The technique hinges on carbon-14, a radioactive isotope of the element that, unlike other more stable forms of carbon, decays away at a steady rate.