The radiocarbon method was developed by a team of scientists led by J.R. Arnold and Professor Willard F. Libby of the University of Chicago. The method was developed in 1949, and has been used by archaeologists ever since..
Radioactivity is when an atom has an unstable nucleus with a combination of nuetrons and protons. The atom will give off particles or energy in order to become stable. The released energy or particles are the radioactivity. Eventually, the atom will change into a different substance which may or may not be radioactive. The time it takes for half of the atoms in radioactive material to decay into another form is known as the "half-life" of the radioactive material. All radioactive materials have half-lives. The half-life's can range anywhere from a few seconds to thousands of years.
In the 1950's, more studies were done on samples from the Mediterranean. This testing was to check and see how accurate the "Libby half-life" was. The age of the items being tested were already known, so archaeologists would be able to determine how accurate the "Libby half-life" was. It was determined that Libby's calculations gave radiocarbon dates that were older than they really were. So because of this, it was determined that a more accurate haqlf-life was 5730�40 years. This half-life was called the "Cambridge half-life".
Carbon-14 is one naturally-occuring radioactive material that can be found in the atmosphere. Plants and animals absorb Carbon-14 through their tissue while they use the air. Once a plant or animal dies, it stops absorbing the Carbon-14 and it begins to decay in their tissue. Since Carbon-14 has a half-life of 5730 years, the length of time the plant or animal has been dead can be determined by finding a sample where the amount of Carbon-14 was only half the amount that would be expected in a living creature. If an archaeologist is able to find this, they would know that the age of the plant or animal would be approximately 5770 years old.