Carbon dating alternatives
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 authors show three times better detection limits than any yet reported for an absorption spectroscopy experiment.” Gianfranco Di Lonardo from the University of Bologna in Italy believes this new technique will improve with further development to become more competitive with AMS-based carbon dating.–Michael Schirber Michael Schirber is a Corresponding Editor for Physics based in Lyon, France.
For decades, radiocarbon dating has been a way for scientists to get a rough picture of when once-living stuff lived.
After turning off the light, mirrors at each end continue to reflect the photons back and forth thousands of times until all of the light goes away.The time it takes for this so-called “cavity ring-down” depends on the degree to which the mirrors are imperfect reflectors but also on the amount of light absorbed by the trace gas.To distinguish the two effects, researchers ordinarily measure the reflection losses separately with an empty cavity.But the system De Natale and his colleagues have developed is times more sensitive because it can isolate the two types of losses with the sample present.For this calibration step, the system essentially turns off the absorption for a short time by using a laser with sufficient power to excite all of the target molecules, putting them into a state in which they can’t absorb light.
Carbon dating relies on carbon-), which corresponds to a sample age of 50,000 years.