Carbon Dating

In news: A Varanasi district court has issued notice regarding carbon-dating of the disputed structure known to have been found inside the premises of the Gyanvapi mosque.

What is Carbon Dating?

• Carbon dating, also called radiocarbon dating is method of age determination that depends upon the decay to nitrogen of radiocarbon (Carbon-14).
• This method was developed by the American physicist Willard F. Libby about 1946.
• Carbon-14 is continually formed in nature by the interaction of neutrons with nitrogen-14 in the Earth’s atmosphere.
• The neutrons required for this reaction are produced by cosmic rays interacting with the atmosphere.

How it works?

• Radiocarbon present in molecules of atmospheric carbon dioxide enters the biological carbon cycle: it is absorbed from the air by green plants and then passed on to animals through the food chain.
• Radiocarbon decays slowly in a living organism, and the amount lost is continually replenished as long as the organism takes in air or food.
• Once the organism dies, however, it ceases to absorb carbon-14, so that the amount of the radiocarbon in its tissues steadily decreases.

The half-life concepts:

• Carbon-14 has a half-life of 5,730 ± 40 years—i.e., half the amount of the radioisotope present at any given time will undergo spontaneous disintegration during the succeeding 5,730 years.
• Because carbon-14 decays at this constant rate, an estimate of the date at which an organism died can be made by measuring the amount of its residual radiocarbon.

Its uses:

• It has proved to be a versatile technique of dating fossils and archaeological specimens from 500 to 50,000 years old.
• The method is widely used by geologists, anthropologists, archaeologists, and investigators in related fields.

Source: Indian Express