For approximate analysis it is assumed that the cosmic ray flux is constant over long periods of time; thus carbon-14 could be assumed to be continuously produced at a constant rate and therefore that the proportion of radioactive to non-radioactive carbon throughout the Earth's atmosphere and surface oceans is constant: ca. For more accurate work, the temporal variation of the cosmic ray flux can be compensated for with calibration curves.

If these curves are used, their accuracy and shape will be the limiting factors in the determination of the radiocarbon age range of a given sample.

In 1960, Libby was awarded the Nobel Prize in chemistry for carbon dating.

Carbon has two stable, nonradioactive isotopes: carbon-12 (12C), and carbon-13 (13C).

In effect, radiocarbon dating established that many artifacts are now known to be far older than previously thought, and thus going back to earlier ages than otherwise could have been if they had been only the inspired and diffused products of the Near Eastern civilization.

Therefore, the notion that the ancient Near East was the fount of global human civilization can no longer hold true.

This is the number of radiocarbon years before 1950, based on a nominal (and assumed constant - see "calibration" below) level of carbon-14 in the atmosphere equal to the 1950 level.

labs generally report an uncertainty, e.g., 3000 -30BP indicates a standard deviation of 30 radiocarbon years.

As far as plant or animal dies, the radiocarbon decays.

An uncalibrated dating using the Libby figure could be improved by multiplying by the ratio of these numbers (approximately 1.03), but this is usually unnecessary since the adjustment is included in modern calibration curves.

had a large impact on archaeology, particularly on many of archaeology's theoretical assumptions until this tool was introduced after World War II.

Clearly, various centers of civilization arose independently of one another even if the Near Eastern one remains the oldest on record.

) and is instantantly mixed throughout the atmosphere.