Libby thus reasoned that by measuring carbon 14 levels in the remains of an organism that died long ago, one could estimate the time of its death.
This procedure of radiocarbon dating has been widely adopted and is considered accurate enough for practical use to study remains up to 50,000 years old.
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. 1979, 1986 © Harper Collins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012 Cite This Source radiocarbon dating A technique for measuring the age of organic remains based on the rate of decay of carbon 14.
Because the ratio of carbon 12 to carbon 14 present in all living organisms is the same, and because the decay rate of carbon 14 is constant, the length of time that has passed since an organism has died can be calculated by comparing the ratio of carbon 12 to carbon 14 in its remains to the known ratio in living organisms. Our Living Language : In the late 1940s, American chemist Willard Libby developed a method for determining when the death of an organism had occurred.
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Some kinds of ulcers are peptic ulcer, pressure ulcer, and serpent ulcer. See Aphthous ulcer GI disease Duodenal ulcer, see there.
See Cushing's ulcer, Dieulafoy ulcer, Peptic ulcer, Stercoral ulcer, Stress ulcer Ophthalmology A defect on the epithelium of the eye.
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