The Notorious Radiocarbon Dating, Part 2

Last week, I said that there are two main differences between radiocarbon dating and other radioisotope dating methods:  the especially short half-life of Carbon-14, which I discussed last time, and now, where the Carbon-14 comes from.  Radioactive carbon forms in earth’s atmosphere when cosmic rays (harmful particles emitted by the sun) hit particles of Nitrogen-14, which are abundant in the atmosphere, converting them into Carbon-14.  Well, that radiocarbon bonds with Oxygen in the atmosphere to form Carbon-14 dioxide, and animals and plants take this radioactive carbon into their bodies by breathing.  When the animal or plant dies, it stops taking in new radiocarbon, and the radiocarbon in its body starts to decay.  Scientists get the “age” of the fossil by comparing amounts of Carbon-14 to Carbon-12 in the animal’s (or plant’s) body to the Carbon-14 to Carbon-12 ratio in today’s atmosphere.

In using this method, scientists have to assume that, 1) the atmosphere has always had the same C-14 to C-12 ratios that it has today, 2) that the number of cosmic rays hitting the atmosphere is fairly constant throughout history, and therefore, 3) that earth’s magnetic field strength has remained about the same throughout history.  The magnetic field around earth is like a shield, protecting us by keeping cosmic rays from entering the atmosphere.  Some still do, but not enough to significantly harm life here.  However, we know for a fact that earth’s magnetic field has not always remained constant because of magnetic anomalies (evidence of pole reversals, like magnet poles) we find in volcanic rock.  Our magnetic field is constantly getting weaker.  Before the flood, the magnetic field would have been much stronger than it is today, which means that it would give much smaller C-14 to C-12 ratios and therefore give us older “dates” than they really are.  This isn’t just some wacky creationist idea either, because, according to the Journal of Radiocarbon, a group of scientists from Arizona drilled core samples from Lake Gun Nur (in Mongolia) and concluded that the inconsistent dates they got from the most advanced kind of radiocarbon dating (Accelerator Mass Spectrometer, or AMS) existed because of a strengthening of earth’s magnetic field

Finally, even evolutionists admit that the atmosphere is not at chemical equilibrium (see http://ebooks.cambridge.org/chapter.jsf?bid=CBO9780511808913&cid=CBO9780511808913A006 for example).  That simply means that the proportions of different chemicals in the atmosphere are not necessarily consistently the same.  This is a big problem for evolutionists, because if the atmosphere really is as old as they want it to be, it should have reached equilibrium long ago.  This concludes my basic explanation of how radiocarbon dating works.  Next week we will continue with some very exciting new discoveries in radiocarbon dating.