Start Uses and application of radiation in radioactive dating

Uses and application of radiation in radioactive dating

In 1958, Hessel de Vries in the Netherlands showed there were systematic anomalies in the carbon-14 dates of tree rings.

Thus the less of it that remained in an object, in proportion to normal carbon, the older the object was.

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.

For example, Hans Suess relied on a variety of helpers to collect fragments of century-old trees from various corners of North America.

He was looking for the carbon that human industry had been emitting by burning fossil fuels, in which all the carbon-14 had long since decayed away.

This was all the usual sort of laboratory problem-solving, a matter of sorting out difficulties by studying one or another detail systematically for months.