Radiocarbon dating used in a sentence Kerala sexy free webfree sexy text chat with girls
After a creature's death the isotope would slowly decay away over millennia at a fixed rate.
Thus the less of it that remained in an object, in proportion to normal carbon, the older the object was.
De Vries thought the variation might be explained by something connected with climate, such as episodes of turnover of ocean waters.(7) Another possible explanation was that, contrary to what everyone assumed, carbon-14 was not created in the atmosphere at a uniform rate.
Some speculated that such irregularities might be caused by variations in the Earth's magnetic field.
An example of the ingenious technical work and hard-fought debates underlying the main story is the use of radioactive carbon-14 to assign dates to the distant past.
For other examples, see the essays on Temperatures from Fossil Shells and Arakawa's Computation Device.
Climate science required the invention and mastery of many difficult techniques.
More unusual was the need to collaborate with all sorts of people around the world, to gather organic materials for dating.
It was an anxious time for scientists whose reputation for accurate work was on the line.
But what looks like unwelcome noise to one specialist may contain information for another.
The radioactive isotope carbon-14 is created in the upper atmosphere when cosmic-ray particles from outer space strike nitrogen atoms and transform them into radioactive carbon.
Some of the carbon-14 might find its way into living creatures.