What is carbon dating?
Carbon dating, or to be more precise, radiocarbon dating, is a method for determining the age of once living material by measuring the amount of carbon 14 remaining in the material. carbon 14 is a radioactive isotope that exists in very small amounts in all living animals and plants. While alive, plants and animals (Animalia, Plantae, Fungi, Protista, Archaea and Bacteria) normally have about one carbon 14 atom for every trillion other carbon atoms. At the moment of death the level of carbon 14 begins to diminish in a predictable and measurable way.
In 1949, Willard Libby at the University of Chicago estimated that it in a gram of carbon there would be 14 disintegrations per minute. Therefore he reasoned that with a sensitive Geiger counter he could determine the age of an object. He demonstrated this by measuring the age of wood from an Egyptian barge which the age was already known from historical records. Libby's method required the to wood or any other material the burned in order to extract pure carbon or carbon dioxide gas. unfortunately, to obtain an accurate measurement required a large sample.
The Shroud of Turin was not a good candidate for Libby’s carbon method. Too much of the shroud would have needed to be destroyed by incineration it to extract the carbon. But a new method using Accelerator Mass Spectrometry (AMS) allowed the cloth’s age to be measured using a much smaller sample. That is what happened in 1988.
- Carbon dating in 1988
- Why are carbon 14 levels consistent in living things?
- Astonishing balancing act in nature
- What do you mean, carbon 14 is radioactive?