Carbon dating job
By combining two chemical techniques—narrow capillary electrophoresis and mass spectrometry—Moini figured out how to measure that ratio in just 20 minutes using microscopic samples of silk. Historical records provided clear dates of manufacture for the museum specimens, and the new technique proved accurate enough to nail down their ages within a 50- to 100-year window, the team reports in the current issue of .Reassured by his nondestructive technique, curators at the Smithsonian and several other museums agreed to let a team led by Moini sample silk objects spanning over 2000 years of history, from ancient Chinese silks and French Renaissance tapestries to a U. The calibration curve “fit very nicely,” Moini says, noting that no silk artwork was harmed.“We know that it is older than Christendom,” he wrote, “but whether by a couple of years or a couple of centuries or even by more than a millennium, we can do no more than guess.” The fog began to lift in the middle of the twentieth century, when US chemist Willard Libby and his colleagues showed that all formerly living things bear a clock powered by radioactive carbon-14.Organisms incorporate tiny amounts of this isotope as they grow, and they maintain a constant ratio between it and other, non-radioactive, carbon isotopes throughout their lives.
Higham thinks that better carbon dating will help to resolve debates about whether the two ever met, swapped ideas or even had sex.At university, he planned to study geography and glaciology, but switched to archaeology after excelling in an introductory course taught by his father that he had signed up for on a whim. “I got less and less interested in archaeology because it was so subjective and woolly.” The reasons for that woolliness were partly technical and partly historical, dating back to before the Highams' time.