RADIOCARBON DATING

RADIOCARBON DATING

TOPIC: Science & Tech

Context- Radiocarbon dating has unmasked two forged paintings in France. The paintings were supposedly impressionist and pointillist works from around the early twentieth century.

• Heritage scientists clipped tiny threads from canvases and plucked what appeared to be a paintbrush bristle trapped in the paint — all were dated to within the past 70 years.

Concept-

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.

Basic Principles of Carbon Dating:

• Radiocarbon (carbon 14) 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).
• Gas proportional counting, liquid scintillation counting and accelerator mass spectrometry are the three principal radiocarbon dating methods.