Why is carbon dating inaccurate after 50000 years
The differences actually found in the scientific literature are usually close to the margin of error, usually a few percent, not orders of magnitude!Vast amounts of data overwhelmingly favor an old Earth.
The simplest means is to repeat the analytical measurements in order to check for laboratory errors.Over a thousand papers on radiometric dating were published in scientifically recognized journals in the last year, and hundreds of thousands of dates have been published in the last 50 years.Essentially all of these strongly favor an old Earth.In a related article on geologic ages (Ages), we presented a chart with the various geologic eras and their ages.In a separate article (Radiometric dating), we sketched in some technical detail how these dates are calculated using radiometric dating techniques.The isochron techniques are partly based on this principle.
The use of different dating methods on the same rock is an excellent way to check the accuracy of age results.
If two or more radiometric clocks based on different elements and running at different rates give the same age, that's powerful evidence that the ages are probably correct.
Along this line, Roger Wiens, a scientist at the Los Alamos National Laboratory, asks those who are skeptical of radiometric dating to consider the following (quoted in several cases from [Wiens2002]): All of the different dating methods agree--they agree a great majority of the time over millions of years of time.
Another method is to make age measurements on several samples from the same rock unit.
This technique helps identify post-formation geologic disturbances because different minerals respond differently to heating and chemical changes.
Other objections raised by creationists are addressed in [Dalrymple2006a].