Until the 18th century, this question was principally in the hands of theologians, who based their calculations on biblical chronology. Bishop James Ussher, a 17th-century Irish cleric, for example, calculated that creation occurred in B. There were many other such estimates, but they invariably resulted in an Earth only a few thousand years old. By the late 18th century, some naturalists had begun to look closely at the ancient rocks of the Earth.
Creation 101: Radiometric Dating and the Age of the Earth
Watch How Does That Work?: Radiometric Dating | Ars Technica Video | CNE
Most absolute age determinations in geology rely on radiometric methods. The earth is billions of years old. The main condition for the method is that the production rate of isotopes stays the same through ages, i. The production of isotopes from chemical elements is known as decay rate and it is considered a constant.
How Does That Work?: Radiometric Dating
Unstable nuclei decay. However, some nuclides decay faster than others. For example, radium and polonium, discovered by Marie and Pierre Curie, decay faster than uranium.
Radiometric dating is not a reliable way to determine the age of a rock. If you want to know what evolutionists believe about radioactive dating, this is the essay to read. We agree. Radiometric dating methods are the strongest direct evidence that geologists have for the age of the Earth. All these methods point to Earth being very, very old -- several billions of years old.