Court rejects plea for carbon dating of Gyanvapi ‘shivling’

Court rejects plea for carbon dating of Gyanvapi ‘shivling’

Subject : Art and Culture

Context : A Varanasi court Friday rejected a plea for carbon dating of what is said to be a Shivling, found during a survey of the Gyanvapi mosque complex earlier this year.

Concept :

• A Shivling was said to have been found in the wazukhana. But the mosque management said it was part of the fountain system of the wazukhana.

What is Wazukhana ?

• Wazukhana is an ablution pond where worshippers wash themselves before praying at the mosque.
• Wazukhanas in historical mosques date back to the time when there were no proper water pipelines.
• Hence, the wazukhanas were established as ponds with fountains to provide sufficient water for the purpose of washing.
• A number of people could make use of the pond simultaneously without wastage of water.

About Radiocarbon Dating:

• Radiocarbon dating (also referred to as carbon dating or carbon-14 dating) is a method that provides objective age estimates for carbon-based materials (Organic materials) that originated from living organisms.
• An age could be estimated by measuring the amount of carbon-14 present in the sample and comparing this against an internationally used reference standard.
• The method was developed in the late 1940s at the University of Chicago by Willard Libby and it is one of the radiometric dating methods.

Basic Principles of Carbon Dating:

• Radiocarbon (carbon14) is an isotope of the element carbon that is unstable and weakly radioactive.
• The stable isotopes are carbon 12 and carbon 13.
• Carbon 14 is continually being formed in the upper atmosphere by the effect of cosmic ray neutrons on nitrogen 14 atoms. It is rapidly oxidized in air to form carbon dioxide and enters the global carbon cycle.
• Plants and animals assimilate carbon 14 from carbon dioxide throughout their lifetimes. When they die, they stop exchanging carbon with the biosphere and their carbon 14 content then starts to decrease at a rate determined by the law of radioactive decay.
• Radiocarbon dating is essentially a method designed to measure residual radioactivity.

How Does Carbon Dating Work:

• Carbon-14 is a weakly radioactive isotope of Carbon; also known as radiocarbon, it is an isotopic chronometer.
• C-14 dating is only applicable to organic and some inorganic materials (not applicable to metals).
• Specifically, it cannot be used to determine the age of non-living things, like rocks, for example.
• Also, the age of things that are more than 40,000-50,000 years cannot be arrived at through carbon dating. This is because after eight to ten cycles of half-lives have been crossed, the amount of carbon-14 becomes almost negligible and undetectable.
• Gas proportional counting, liquid scintillation counting and accelerator mass spectrometry are the three principal radiocarbon dating methods.

Other Radiometric Methods

Single Crystal Fusion

• Also called single crystal argon or argon-argon (Ar-Ar) dating, this method is a refinement of an older approach known as potassium-argon (K-Ar) dating, which is still sometimes used.
• Both methods date rock instead of organic material. As potassium decays, it turns into argon.
• But unlike radiocarbon dating, the older the sample, the more accurate the dating — researchers typically use these methods on finds at least 500,000 years old.
• While K-Ar dating requires destroying large samples to measure potassium and argon levels separately, Ar-Ar dating can analyze both at once with a single, smaller sample.

Uranium Series Dating

• U-series dating includes a number of methods, each based on different uranium isotopes’ decay rates.
• The uranium-thorium method is often helpful for dating finds in the 40,000- to 500,000-year-old range, too old for radiocarbon but too young for K-Ar or Ar-Ar.

Trapped Charge Dating

• Over time, certain kinds of rocks and organic material, such as coral and teeth, are very good at trapping electrons from sunlight and cosmic rays pummeling Earth. Researchers can measure the amount of these trapped electrons to establish an age.

For further details about ‘Gyanvapi Case’ refer – https://optimizeias.com/gyanvapi-mosque-dispute