Virtually all fossils found within sedimentary rocks are the remains of creatures that perished during the Genesis Flood about 4,500 years ago.Yet a skeptic might point out that the amounts of C found in these organic samples are smaller than what one might expect if they are only about 4,500 years old.
Second, such large calculated ages are based on the C/C ratio has remained unchanged for tens of thousands of years.
A global flood like the one described in the Bible would invalidate this assumption.
Are these high radiocarbon “ages” a problem for the biblical worldview? First, remember that no detectable should be present within these samples if they really are millions of years old.
Despite this apparent difficulty for the recent-creation view, this is, in fact, a much more serious problem for the old-earth view!
Yet this assumption leads to a contradiction: If these organic samples really are many millions of years old, then they should be radiocarbon “dead.” But they aren’t! Evolutionists have attempted to blame these surprising results on a number of mechanisms. Furthermore, laboratories take great pains to keep contamination to a minimum, and researchers have found that, provided a sufficiently large testing sample is used (in the ballpark of 100 milligrams or so), the amount of such possible lab contamination is negligible compared to the C already present within the specimen.
Finally, although contamination can sometimes occur, it should not be assumed in a particular instance unless there are good reasons to believe that it has.
Because the present decay rates of these heavier isotopes are so small, the assumption that these rates have always been constant naturally leads to age estimates of millions and even billions of years.
Interestingly, however, some radioisotope methods tend to consistently yield younger age estimates than others, even when the techniques are used on the same rock units.
One of these assumptions is that nuclear decay rates have always been constant.
Although C decays fairly quickly, heavier isotopes (such as uranium-238) decay much more slowly.
Radioisotope dating methods involving the heavier, longer-lived isotopes (methods such as uranium-lead, potassium-argon, etc.) are one of the main justifications that evolutionists use to argue for such vast ages.