Scientific american carbon dating

23 Dec

Following a bidding war between two avid collectors, the seven-bottle lot sold for a whopping 7,500 (almost ,000 per bottle) in a 2001 auction at New York City's Sotheby's.With rare vintages, like the Montrachet, collecting stratospheric prices, misrepresenting a wine's vintage and wine fraud in general is a major concern."This changed in the late 1940s up to 1963 when atmospheric atomic explosions significantly increased the amount of C-14 in the atmosphere." When the bomb tests stopped in 1963, the clock started ticking as the atmospheric carbon 14 from the "bomb-pulse" was diluted by carbon dioxide generated by the burning of fossil fuels, according to Jones.The vintage-determining process requires careful examination of the wine using an accelerator mass spectrometer (an expensive device that determines the elemental composition of a sample), so don't expect bottles from the local liquor store to be carbon dated anytime soon.A T-shirt made in 2050 could look exactly like one worn by William the Conqueror a thousand years earlier to someone using radiocarbon dating if emissions continue under a business-as-usual scenario.By 2100, a dead plant could be almost identical to the Dead Sea scrolls, which are more than 2,000 years old.That's where two decades of atomic bomb testing can offer clues.

"So far there have probably been more fakes among the samples we've tested than real examples of old whisky," Tom Higham, deputy director of the ORAU, told .

Radiocarbon decays slowly in a living organism, and the amount lost is continually replenished as long as the organism takes in air or food.

Once the organism dies, however, it ceases to absorb carbon-14, so that the amount of the radiocarbon in its tissues steadily decreases.

Radiocarbon, or carbon 14, is an isotope of the element carbon that is unstable and weakly radioactive. Carbon 14 is continually being formed in the upper atmosphere by the effect of cosmic ray neutrons on nitrogen 14 atoms.

It is rapidly oxidized in air to form carbon dioxide and enters the global carbon cycle.