How Is Carbon Dated to Determine Age?

Imagine a tiny clock ticking inside every leaf and bone. This is carbon14, a special type of carbon that slowly fades away over time. When a plant dies, it stops eating new carbon, so its clock starts running. By counting how much is left, we know how long ago it died.

The Cosmic Clock

Cosmic rays from space hit the Earth and create these special atoms in the air. Plants breathe them in when they grow. Animals eat the plants. Everyone has a little bit of carbon14 inside them.

What Happens When We Die?

Life keeps the clock steady because we are always eating or breathing. But death stops the supply. The carbon14 begins to turn into nitrogen, like ice melting in the sun. It takes about 5,730 years for half of it to disappear.

Reading the Time

Scientists take a small piece of an old bone or wood. They count the remaining carbon14 atoms using a special machine. If there is very little left, the object is very old. If there is still a lot, it is young. It is like finding a sandglass and seeing how much sand has fallen.

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Examples

  1. A wooden spoon found in a dusty cave has lost half its carbon14, meaning it is about 5,730 years old.
  2. Fossils of ancient ferns trapped in amber still hold tiny amounts of their original radioactive carbon atoms.
  3. Scientists put a piece of old cloth into a machine that counts the remaining carbon14 like counting stars.

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