The Source

by James A. Michener

Carbon-14, on the other hand, is an unstable, radioactive substance heavier than normal carbon. It is formed in the earth’s upper atmosphere and finally mixes itself into our atmosphere in the almost imperceptible ratio of one-trillionth of a part of Carbon-14 to one part of Carbon-12. But even such a slight trace of the heavier carbon is detectable in all things that live or have ever lived; as long as they continue to live they absorb Carbon-14, but at the moment of death they absorb no more. Carbon-14 would be of no significance to archaeologists except for a peculiarity which makes it invaluable. At the death of a living organism, its Carbon-14 content, which is non-stable, begins to disintegrate, losing half its remaining total every 5,500 years. For example, if the ram’s horn that Jemail Tabari dug out of the fire-level at Makor were found to retain only half its Carbon-14, it could be dated roughly 3535 B.C.E., plus or minus 330 years, so that the ram which grew the horn must have died sometime between the years 3205 B.C.E. and 3865 B.C.E.