Radiocarbon dating also referred to as carbon dating or carbon dating is a method for determining the age of an object containing organic material by using the properties of radiocarbon , a radioactive isotope of carbon. The method was developed in the late s at the University of Chicago by Willard Libby , who received the Nobel Prize in Chemistry for his work in It is based on the fact that radiocarbon 14 C is constantly being created in the atmosphere by the interaction of cosmic rays with atmospheric nitrogen. The resulting 14 C combines with atmospheric oxygen to form radioactive carbon dioxide , which is incorporated into plants by photosynthesis ; animals then acquire 14 C by eating the plants.
Radiocarbon dating - Wikipedia
Carbon dating uses the ratio of radioactive carbon to non-radioactive carbon to determine if the ratio is the same as in living organisms, or if it is lower, indicating that the carbon has decayed during a period of thousands of years. Carbon has a half-life of 5, years, which is the amount of time that it takes for half of a given sample of carbon to decay. Carbon is only a small percentage of the total carbon in the environment and originates in the atmosphere when cosmic rays and high-speed particles from space hit nitrogen atoms. Although the physics are more complicated than this, essentially the nitrogen atoms lose a proton and gain a neutron to become carbon Plants take up carbon when they convert CO2 into sugar and build cellular structures. Animals take up carbon when they eat plants or other animals. These organisms no longer take in new carbon once they've died, so the carbon isn't replenished as it decays back into nitrogen.
Carbon Dating Gets a Reset
Rachel Wood does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment. Republish our articles for free, online or in print, under Creative Commons licence. Radiocarbon dating has transformed our understanding of the past 50, years. Professor Willard Libby produced the first radiocarbon dates in and was later awarded the Nobel Prize for his efforts. Radiocarbon dating works by comparing the three different isotopes of carbon.
There are many carbon atoms in our environment. The vast majority of these are 12 C pronounced "c twelve" , the stable isotope of carbon. However, cosmic radiation constantly collides with atoms in the upper atmosphere. Part of the result of these collisions is the production of radiocarbon 14 C, pronounced "c fourteen" , carbon atoms which are chemically the same as stable carbon, but have two extra neutrons.