The Radiometric Time Scale

The Radiometric Time Scale is a method scientists use to determine the age of rocks and fossils by measuring the decay of naturally occurring radioactive isotopes within them. These isotopes, like uranium or carbon, break down at known rates over time into stable elements. By comparing the amounts of parent (original) and daughter (decayed) isotopes, scientists can calculate how long this process has been happening, providing an estimate of when the rock or fossil formed. This technique allows us to understand Earth's history spanning millions to billions of years.