How do we know that dinosaurs lived on Earth millions of years ago? From their fossils of course. But how do we know their age? One way to do it is through radiocarbon dating.
The ages of objects can be determined by finding out the amount of radiocarbon in it. All living things Contain traces of carbon-14, a radio-active element of carbon. Dating an object with the help of radiocarbon is known as ‘radiocarbon dating’ and it can date objects up to 50,000 years old. Willard Libby first proposed this innovative method for dating organic material in 1946 which is done by determining the half-life of radioactive carbon.
Carbon-14 is formed when Cosmic rays hit the atmosphere and react with atmospheric nitrogen. Carbon -14 is taken in by plants which in turn enters all living organisms through the food chain. When an animal or a plant dies, carbon-14 atoms decay at a steady rate. The amount of carbon-14 in a dead plant or animal can give us information regarding when it died. The process lies in finding the amount of carbon-14 and dating it using half-life of the element. Half-life is defined as the period of time after which half of a given sample will have decayed. The half-life of carbon-14 is about 5,500 years. This means that after 5,500 years after the death of a plant or an animal, half the carbon-14 atoms at the time of its death won’t be present. Therefore, the lesser the amount of carbon-14, the older the sample.
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