Quote:
Originally Posted by fatfoo
67 million-year-old?
How can they tell the age? That's impossible.
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absolute dating, also known as carbon-14 dating, relies upon the availability of enough organic material being present in the fossil to measure a radioactive isotope and its by-product, carbon-14. Since the rate of expiration of the isotope is known to be constant, the scientist can tell a fossil's age by comparing the amount of isotope present to the amount of the by-product. This method can be used to date fossils up to 40,000 years old. Older specimens are dated by measuring other by-products, such as uranium-235.
google makes me look smart