Illustration by Jayne Doucette, Woods Hole Oceanographic Institution When it comes to history and especially archaeology one of the biggest questions is "When did it happen?" In 1940 Martin Kamen introduced the world to Carbon14. Carbon14 (C14) is an isotope of Carbon. If you are not sure why it is Carbon14 as opposed to just Carbon or a different isotope, such as Carbon12 (C12), it has to do with the number of protons and neutrons that each contain. All carbon atoms have 6 protons, but the isotopes C14 and C12 have different numbers of neutrons and thus have differing levels of radioactivity, a C12 isotope has 6 neutrons therefore C14 has 8 neutrons, this difference in numbers of neutrons also changes the mass(weight) of the atoms as well. Willard F. Libby via ACS Seven years later Willard F. Libby presented the world with a method using C14 for radiocarbon dating. The theory of radiocarbon dating is based on the belief that the atmosphere contains a constant amoun...
Curious Adventures Into History and Deep Antiquity