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Retrieved 12 September 2014. Why Don't Penguins' Feet Freeze?. The Editor-in-chief is Sumit Paul-Choudhury, Executive Editor is Graham Lawton, Managing Editor is Rowan Hooper and Editor-at-Large is Jeremy Webb.

See our and for details. A back scene between the strain of person headed in the attacks and a line in the collection would have stuck hints as to when backgrounds had been isolated and, perhaps, as to how towards it had been made to us. The main threat to the region continues to be small-scale habitat clearance — predominantly for firewood and charcoal production.

New scientist dating. Stonehenge secret revealed? Scientist suggests new theory about ancient site.

From magazine The carbon clock is getting reset. 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. Various geologic, atmospheric and solar processes can influence atmospheric carbon-14 levels. 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. Two distinct sediment layers have formed in the lake every summer and winter over tens of thousands of years. The researchers collected roughly 70-metre core samples from the lake and painstakingly counted the layers to come up with a direct record stretching back 52,000 years. Take the extinction of Neanderthals, which occurred in western Europe less than 30,000 years ago. Archaeologists vehemently disagree over the effects changing climate and competition from recently arriving humans had on the Neanderthals' demise. The more accurate carbon clock should yield better dates for any overlap of humans and Neanderthals, as well as for determining how climate changes influenced the extinction of Neanderthals. 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. This article is reproduced with permission from the magazine. The article was first published on October 18, 2012. ABOUT THE AUTHOR S.

They cannot beginning it to any conflicting. Does Anything Eat Wasps?. Forensic pathologists, microbiologists, and botanists have analyzed its bloodstains, along with specks of dirt and pollen on its surface. The even smaller-brained of Indonesia lived on an isolated island and apparently went extinct shortly after the arrival of modern humans. New Scientist Media Centre. The skeletal anatomy presents features known from with associated with later hominins.