As of the mid-1940s, radioactive dating had not attracted serious attention from the majority of evangelicals.
Since the invention of the C-14 method and the appearance of evangelical professionals in this field, however, American evangelicals have divided themselves into two groups.
These two measures of time will only be the same if all of the assumptions which go into the conventional radiocarbon dating technique are valid.
Comparison of ancient, historically dated artifacts (from Egypt, for example) with their radiocarbon dates has revealed that radiocarbon years and calendar years are not the same even for the last 5,000 calendar years.
This paper traces the reactions of Seventh-day Adventists and American evangelical Christians toward C-14 dating.
Among several radioactive dating methods, the radiocarbon (C-14) dating method (which was invented by Willard Frank Libby of the University of Chicago in the late 1940s) occupies a special position in archaeology and ancient history, as well as geology, because it can give the absolute age of those carbonaceous archaeological findings that were not older than the half-life of C-14.
Other radiometric dating methods such as potassium-argon or rubidium-strontium are used for such purposes by those who believe that the earth is billions of years old.
Radiocarbon is not suitable for this purpose because it is only applicable: a) on a time scale of thousands of years and b) to remains of once-living organisms (with minor exceptions, from which rocks are excluded).
The other, non-literalist group of evangelicals accepted some kinds of evolutionary uniformitarian hypotheses and radioactive dating.Radiohalos or pleochroic halos are microscopic, spherical shells of discolouration within minerals such as biotite that occur in granite and other igneous rocks.The shells are zones of radiation damage caused by the inclusion of minute radioactive crystals within the host crystal structure.The phenomenon of radiohalos has been known to geologists since the early part of the 20th century, but wider interest has been prompted by the claims of creationist Robert V.Gentry that radiohalos in biotite are evidence for a young earth (Gentry 1992).