Friday, March 25, 2011

Oh by the way....

[It seemed like a good idea at the time?]

from an article in yesterday's New York Times about dating a prehistoric campsite in Texas containing pre-Clovis artifacts (before this dig no one knew there had been pre-Clovis anything) --
Given the lack of sufficient organic material buried around the tools, the radiocarbon dating method was useless. Instead, earth scientists at the University of Illinois, Chicago, used a newer technique known as optically stimulated luminescence. This measures light energy trapped in minerals to reveal how long ago the soil was last exposed to sunlight.
Quite apart from the stunning revelation that there have been people in North America longer than anyone thought, is the 'oh-by-the-way' mention of the new technology used to date it.

Optically stimulated luminescence is hugely important for all the stuff it can be used for directly, and just as important for confirming and refining dates found by other means like radio-carbon dating, uranium dating, tree rings, oxygen isotope dating, ice cores and seabottom ooze dating, and the venerable suite-of-fossils dating, every one of which has serious limitations. Optically stimulated luminescence is potentially huge for the dating of practically anything and everything. Our understanding of the history of everything that has happened in the past many thousands of years is about take a huge leap forward. Wikipedia says it can be used to date things buried between 300 and 100,000 years ago.

With their usual acumen the Times didn't think to mention it except in passing.

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