The level is affected by variations in the cosmic ray intensity, which is, in turn, affected by variations in the Earth’s magnetosphere.
The dating method is based on the fact that carbon is found in various forms, including the main stable isotope (carbon 12) and an unstable isotope (carbon 14).Through photosynthesis, plants absorb both forms from carbon dioxide in the atmosphere.And if the artifact is organic, like wood or bone, researchers can turn to a method called radiocarbon dating.Radiocarbon dating, or simply carbon dating, is a technique that uses the decay of carbon 14 to estimate the age of organic materials.The excavator might employ relative dating, using objects located stratigraphically (read: buried at the same depth) close to each other, or he or she might compare historical styles to see if there were similarities to a previous find.
But by using these imprecise methods, archeologists were often way off.Radio carbon dating determines the age of ancient objects by means of measuring the amount of carbon-14 there is left in an object.A man called Willard F Libby pioneered it at the University of Chicago in the 50's. This is now the most widely used method of age estimation in the field of archaeology.This method works effectively up to about 58,000 to 62,000 years.Since its introduction it has been used to date many well-known items, including samples of the Dead Sea Scrolls, enough Egyptian artifacts to supply a chronology of Dynastic Egypt, and Otzi the iceman.Fortunately, Willard Libby, a scientist who would later win the 1960 Nobel Prize in Chemistry, developed the process known as radiocarbon dating in the late 1940s. In a nutshell, it works like this: After an organism dies, it stops absorbing carbon-14, so the radioactive isotope starts to decay and is not replenished.