New radiocarbon dating of fossils suggests dating southamerica
Isotopes of a particular element have the same number of protons in their nucleus, but different numbers of neutrons.
This means that although they are very similar chemically, they have different masses.
In addition, samples need to be thoroughly cleaned to remove carbon contamination from glues and soil before dating.
This is particularly important for very old samples.
In this way large domed tombs (known as tholos or beehive tombs) in Greece were thought to predate similar structures in the Scottish Island of Maeshowe.
Because of this, radiocarbon chemists are continually developing new methods to more effectively clean materials.In 2008 we could only calibrate radiocarbon dates until 26,000 years.Now the curve extends (tentatively) to 50,000 years.Radioactive decay can be used as a “clock” because it is unaffected by physical (e.g. For instance, the amount varies according to how many cosmic rays reach Earth.This is affected by solar activity and the earth’s magnetic field.
Professor Willard Libby produced the first radiocarbon dates in 1949 and was later awarded the Nobel Prize for his efforts.