Carbon dating news articles
For decades, radiocarbon dating has been a way for scientists to get a rough picture of when once-living stuff lived.The method has been revolutionary and remains one of the most commonly used dating methods to study the past. Pearson, an assistant professor of dendrochronology at the University of Arizona, studies the past lives of trees to better understand the history of civilizations.Dendrochronology and radiocarbon dating have intertwined histories, she explains, with roots firmly planted at the UA.A 1929 edition of National Geographic boasts, "The Secret Of The Southwest Solved By Talkative Tree Rings." The 35-page article, penned in whimsical prose, was written by Andrew Douglass, the UA scientist who invented tree ring science. In addition to his work as an astronomer at the UA's Steward Observatory, Douglass was the first to discover that tree rings record time.In 1929, with a beam from Show Low, Arizona, Douglass was able to bridge the gap for the first time ever.Dates were assigned to Southwestern ruins with certainty.The first single-celled organisms on Earth did not appear until about a billion years later.
"We can use the annual precision of tree rings in combination with carbon-14 to underpin some big questions in terms of the rise and fall of civilizations," says Pearson.The world is made of tiny building blocks called 'elements'.Scientists have worked out how fast some elements change into other elements.Willard Libby from the University of Chicago put it to the test.
By 1949, he had published a paper in Science showing that he had accurately dated samples with known ages, using radiocarbon dating.Douglass passed away just two years after Libby received the Nobel Prize for his work in 1960.Radiocarbon Dating Tree Rings Today Today, dendrochronologists all over the world follow in Douglass' footsteps, and whenever it is not possible to use tree-ring dating to place wood samples in time, they use radiocarbon to date wood samples.A decade after Douglass's big discovery, two Berkeley scientists took the first step towards an alternative way to date floating chronologies and indeed any other "once-living" thing. Also known as radiocarbon, carbon-14 is a radioactive isotope of carbon with an atomic nucleus of six protons and eight neutrons. They discovered its half-life, or the time it takes for its radioactivity to fall by half once the living thing dies, is 5,730 years (give or take 40).