Topics: RTÉ - Mooney Goes Wild
Absolute dating is the process of determining an age on a specified chronology in archaeology and geology. Some scientists prefer the terms chronometric or calendar dating , as use of the word "absolute" implies an unwarranted certainty of accuracy.   Absolute dating provides a numerical age or range in contrast with relative dating which places events in order without any measure of the age between events.
In historical geology , the primary methods of absolute dating involve using the radioactive decay of elements trapped in rocks or minerals, including isotope systems from very young (radiocarbon dating with 14
C ) to systems such as uranium-lead dating that allow acquisition of absolute ages for some of the oldest rocks on earth.
One of the most widely used and well-known absolute dating techniques is carbon-14 (or radiocarbon ) dating, which is used to date organic remains. This is a radiometric technique since it is based on radioactive decay. Cosmic radiation entering the earth’s atmosphere produces carbon-14, and plants take in carbon-14 as they fix carbon dioxide. Carbon-14 moves up the food chain as animals eat plants and as predators eat other animals. With death, the uptake of carbon-14 stops.