Who uses radiometric dating
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.
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.
As for still earlier periods, carbon-14 dating excited scientists (including some climate scientists) largely because it might shed light on human evolution the timing of our development as a species, and how climate changes had affected that.(2) It was especially fascinating to discover that our particular species of humans arose something like 100,000 years ago, no doubt deeply influenced by the ice ages.(3) A few scientists noticed that the techniques might also be helpful for the study of climate itself.
Thus the less of it that remained in an object, in proportion to normal carbon, the older the object was.Any contamination of a sample by outside carbon (even from the researcher's fingerprints) had to be fanatically excluded, of course, but that was only the beginning.Delicate operations were needed to extract a microscopic sample and process it.In 1958, Hessel de Vries in the Netherlands showed there were systematic anomalies in the carbon-14 dates of tree rings.His explanation was that the concentration of carbon-14 in the atmosphere had varied over time (by up to one percent).