Radiometric dating

How Scientists Find the Age of Old Things

Scientists have a special way to find out how old rocks, bones, and even very old buildings are. This way is called radiometric dating. It is like a clock inside tiny parts of materials that change very slowly over time.

To use this method, scientists look at special tiny bits in rocks and other things. These bits are called isotopes. Some of these isotopes change, or decay, into other bits over time. The speed of this change is always the same, like a very slow and steady clock. By measuring how much of the original bit is left, scientists can figure out how many years have passed.

Two famous scientists, Ernest Rutherford and Bertram Boltwood, helped create this method a long time ago. Now, radiometric dating helps us learn about Earth’s history, like when dinosaurs lived or how old our planet is.

One common type of radiometric dating is radiocarbon dating. It works well for things that were once alive, like wooden tools or old bones. Another type, uranium-lead dating, helps find the age of very old rocks. These amazing tools let scientists turn rocks into time machines, showing us events from millions and millions of years ago.

Fun Picture

These pictures show how scientists use special diagrams and tools to find the age of rocks and ancient places.