What is Radiocarbon Dating?

• ‘Dating’ is a method by which the age of an object can be determined. Radiocarbon dating refers to a method that does this using radiocarbon, a name for the isotope carbon-14. 
• Carbon-14 is created in the earth’s atmosphere when cosmic rays – energetic streams of charged particles coming from sources in outer space – slam into the atoms of the gases and release neutrons. 
• When these neutrons interact with the nitrogen-14 nitrogen isotope, they can produce carbon-14. Since cosmic rays are ceaselessly passing through the earth’s atmosphere, carbon-14 is created constantly there.
• Carbon-14 readily combines with atmospheric oxygen to form radioactive carbon dioxide. This compound then enters the bodies of plants (via photosynthesis), animals (when they consume plants), and other biomass through the carbon cycle.

How does radiocarbon dating work?

• When an organic entity –  like the human body – is ‘alive’, it constantly exchanges carbon with its surroundings by breathing, consuming food, defecating, shedding skin, etc. 
• Through these activities, carbon-14 is both lost from the body as well as replenished, so its concentration in the body is nearly constant and in equilibrium with its surroundings.
• When this individual dies, the body no longer performs these activities and the concentration of carbon-14 in the body begins to dwindle through radioactive decay. 
• The more time passes, the more the amount of carbon-14 lost, and the less there will remain. This decay rate can be predicted from theory.
• Radiocarbon dating dates an object by measuring the amount of carbon-14 left, which scientists and/or computers can use to calculate how long ago the body expired.

Tools used in Radiocarbon dating

• Geiger muller counter is an electronic instrument used for detecting and measuring ionizing radiation.
• Accelerator mass spectrometry dating involves accelerating the ions to extraordinarily high kinetic energies followed by mass analysis. Although more expensive than radiometric dating, AMS dating has higher precision and needs small sample sizes.