Dead eyes speak no lies

Perhaps rather uniquely at this point in history, we can take advantage of historical events and a certain fact of nature to estimate the age of a person through analysing crystals in the eyes.

Up until about two years of age, we construct a crystal element in the lenses of our eyes. Since this material consists of carbon we've harvested from the food chain, it will mostly be of a certain isotope called C-14. Normally C-14 degrades into C-12, yet it is replaced consistently while an organism still lives and eats; comparing these levels will tell us how long organic material has been unable to replace its carbon for (i.e., how long it's been dead). However, during the 1960s there was a surge of nuclear testing in light of the Cold War, dumping higher amounts of the C-14 isotope. Since then the level has decreased, giving a gradient over time against which we can compare the crystals in the eye (which stop replacing carbon a year or two after birth).

http://www.sciencedaily.com/releases/2008/01/080129201238.htm

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