Radiometric age dating accuracy - Age of the Earth - Wikipedia

Geologist Ralph Harvey and historian Mott Greene explain the principles of radiometric dating and its application in determining the age of Earth in this video segment from A Science Odyssey . As the uranium in rocks decays, it emits subatomic particles and turns into lead at a constant rate. Measuring the uranium-to-lead ratios in the oldest rocks on Earth gave scientists an estimated age of the planet of billion years.

It is hypothesised that the accretion of Earth began soon after the formation of the calcium-aluminium-rich inclusions and the meteorites. Because the exact amount of time this accretion process took is not yet known, and the predictions from different accretion models range from a few million up to about 100 million years, the exact age of Earth is difficult to determine. It is also difficult to determine the exact age of the oldest rocks on Earth, exposed at the surface, as they are aggregates of minerals of possibly different ages.

Information on the nature of atoms, half-lives, and types of radioactive decay was taken from ATOM: Journey Across the Subatomic Cosmos, by Isaac Asimov (c. Nightfall, Inc., 1991).

Radiometric age dating accuracy