After an organism dies, the radiocarbon decreases through a regular pattern of decay. The time taken for half of the atoms of a radioactive isotope to decay in Carbon-14’s case is about 5730 years.
Half-lives vary according to the isotope, for example, Uranium-238 has a half-life of 4500 million years where as Nitrogen-17 has a half-life of 4.173 seconds!
The Mayan calendar used 3114 BC as their reference.
More recently is the radiocarbon date of 1950 AD or before present, BP.
His radiocarbon dating technique is the most important development in absolute dating in archaeology and remains the main tool for dating the past 50,000 years.The extra neutrons in Carbon-14’s case make it radioactive (thus the term, radiocarbon).Radiocarbon is produced in the upper atmosphere after Nitrogen-14 isotopes have been impacted by cosmic radiation.The Greeks consider the first Olympic Games as the beginning or 776 BC.The Muslims count the Prophet’s departure from Mecca, or the Hegira, as their beginning at AD 662.How It Works: Carbon has 3 isotopic forms: Carbon-12, Carbon-13, and Carbon-14.