Here's how it works:
* Radioactive isotopes decay at a predictable rate: Certain elements within rocks and fossils are radioactive. These isotopes decay over time, transforming into other elements. The rate of decay is constant and known as the "half-life."
* Measuring the ratio of isotopes: Geologists measure the amount of the original radioactive isotope and its decay product in a sample.
* Calculating the age: By comparing the measured ratio to the known half-life, they can calculate how long it took for the decay to occur, giving them the age of the sample.
This method is essential for understanding Earth's history, the evolution of life, and the formation of geological formations.
