In most cases, the three methods produced similar results.Surprisingly, in at least one case the date range given by There may be other examples of systematic variation in isotope decay rates.Carbon-14 dating cannot be applied to materials that have no C dates are less than that figure.
The reasonableness of this assumption probably depends on the environment around the sample.
A sample that is sealed from the surrounding environment is more likely to avoid contamination or loss than one in an open environment where materials may be carried into or out of the sample by water or simple diffusion.
Other processes may affect the local concentrations of carbon-14.
These effects are corrected for by comparing samples from different locations.
In practice, there are sufficient variations in these conditions that it is necessary to correct a sample’s raw radiocarbon age by comparing it with the standard calibration curve.
Carbon-14 dating depends on the amount of atmospheric carbon-14 relative to carbon-12.
Violations in the atmosphere result from volcanic eruptions that occasionally add C.
Also, there is a lag time for atmospheric mixing in the northern and southern hemispheres which results in somewhat different ages for the two hemispheres.
It is widely used in dating fossils or archaeological samples containing organic material such as wood, charcoal, bone, shells, etc.
It is not used to date rocks or other inorganic material.
A straightforward reading of the Bible describes a 6,000-year-old universe, and because some carbon-14 (C) age estimates are multiple tens of thousands of years, many think that the radiocarbon method has soundly refuted the Bible’s historical accuracy.