Climate records from a Japanese lake are set to improve the accuracy of the dating technique, which could help to shed light on archaeological mysteries such as why Neanderthals became extinct.Carbon dating is used to work out the age of organic material — in effect, any living thing.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.Organisms capture a certain amount of carbon-14 from the atmosphere when they are alive.By measuring the ratio of the radio isotope to non-radioactive carbon, the amount of carbon-14 decay can be worked out, thereby giving an age for the specimen in question.But that assumes that the amount of carbon-14 in the atmosphere was constant — any variation would speed up or slow down the clock.The clock was initially calibrated by dating objects of known age such as Egyptian mummies and bread from Pompeii; work that won Willard Libby the 1960 Nobel Prize in Chemistry.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.
Since the 1960s, scientists have started accounting for the variations by calibrating the clock against the known ages of tree rings.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.Marine records, such as corals, have been used to push farther back in time, but these are less robust because levels of carbon-14 in the atmosphere and the ocean are not identical and tend shift with changes in ocean circulation.
Interesting dating question comments
Simple laboratory Hf leaching experiments of zircon provide a clear link between enhanced solubility of U234 and radiogenic lead due to alpha-recoil damage Davis and Krogh submitted; Mattinson 1994.…
Fun Relationship Questions LoveToKnow
Trending in Dating. What to Talk About with Your Boyfriend By Heather Long. 1312K. Romantic Things to Say to Your Lover By Kelly Roper. 532K.…
Top 100 Questions to Ask Your Potential Boyfriend.
Dec 27, 2012 Dating is all about having fun. It is interesting also. 402 Responses to 2016 Top 100 Questions to Ask Your Potential Boyfriend/Girlfriend…
Questions To Ask Your Boyfriend, Random, Interesting, Good, Some
Questions To Ask Your Boyfriend. Are looks important in someone you're dating? 25. Interesting Questions to Ask Your Boyfriend 31.…
Interesting Questions To Ask Women Made Man
Sep 27, 2010 Another interesting question for women that can give you. When it comes to interesting questions to ask women. If you're new to the dating.…