3 assumptions of radiometric dating
It is known that such variations have occurred, but it is thought they can be corrected for by comparing a sample’s C level with the standard curve constructed using samples of known age.Another assumption is that the amounts of carbon-14 present in the geophysical reservoirs must be constant.
Special emphasis is on demonstrating that discrepant results are not the exception, but the rule, and that arguments used to justify so-called good dates are, when closely examined, arbitrary and without foundation. But the reality of the day is that any method based on assumptions can never offer absolute results.Carbon-14 dates usually appear to be reasonably accurate whenever they can be checked against historical records.For example, when the Dead Sea Scrolls were dated, three methods could be used: 1) Dates written in the documents themselves (like the date at the start of a letter) 2) Paleography, which uses the style of script used to write documents to date them, and 3) Carbon-14.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.
Carbon-14 dating does not produce ages in the millions of years, as do some other types of radioisotope dating.