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.
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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.
The use of ought to is similar to should, but it is much less frequent.
Like should, the verb ought to does not have a past form.
In pure iron, the crystal structure has relatively little resistance to the iron atoms slipping past one another, and so pure iron is quite ductile, or soft and easily formed.
In steel, small amounts of carbon, other elements, and inclusions within the iron act as hardening agents that prevent the movement of dislocations that are common in the crystal lattices of iron atoms.
Once an organism is dead, however, no new carbon is actively absorbed by its tissues, and its carbon 14 gradually decays.
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.
90% of the time, speakers of English use just 7,500 words in speech and writing.