Brief history carbon dating
Another problem derives from the “reservoir effect” in which old material, limestone or graphite, has contaminated the samples. This is particularly true of marine samples and contemporary shells may seem to be hundreds of years old. Before this, it was anyone's guess how different digs' timelines compared to one another over great distances.But now archaeologists studying, say, the development of agriculture across the continents are able to determine how different societies stacked up against one another throughout the millennia.But by using these imprecise methods, archeologists were often way off.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.While other methods of dating objects exist, radiocarbon dating has remained vital for most archaeologists.For example, it makes it possible to compare the ages of objects on a worldwide scale, allowing for indispensible comparisons across the globe.
Other isotopes are used by geologists to date older material.Archaeologists can then measure the amount of carbon-14 compared to the stable isotope carbon-12 and determine how old an item is.For the most part, radiocarbon dating has made a huge difference for archaeologists everywhere, but the process does have a few flaws.One standard deviation has a 68% probability and two standard deviations have a 95% probability.Radiocarbon dating has had an enormous impact on archaeology around the world since it made it possible to date carbon and wood could be directly without dependence on characteristic artifacts or written historical records.