I do not fully understand who is correct on dating, but as a creationist I tend to be biased. I hear that radioactive dating usually generates multiple dates, and the correct date is chosen if it agrees with geological dates (does this make sense?). I also understand that dating methods usually rely on 3 assumptions;
1-constant radioactive decay
2-parent/daughter relationships
3-contamination/leaking
From these assumptions alone it seems that dating can be extremely biased, if dating results do not agree, tweak a few of these valuse to suit your dates.
There is a RATE (Radioisotopes and the age of the earth) team out there to 'investigate', now these are creationists (of course, why would evolutionists want to undermine their own methods). So at the moment the research will appear heavily biased. I just hope once the research is finished, some evolutionists opinions can be collected on this.
"RATE geophysicist Dr. John Baumgardner reported on the detection of 14C in coal and in diamonds. Since 14C is a short-lived radioisotope, it cannot survive for millions of years. This is compelling evidence that these diamonds and coal deposits are thousands of years old at most. In particular, the hard lattice structure of a diamond makes any sort of contamination extremely unlikely. Dr. Baumgardner also stated that 14C is found in essentially all fossil organic material throughout the geologic column."
"Dr. Andrew Snelling (Ph.D. in geology) reported on the topic of radiohalos (tiny spheres of discolored crystal produced by the decay of radioactive material at their center) and fission tracks. His research strongly indicates that uranium must have decayed much more quickly in the past”an independent confirmation of accelerated decay."
quotes from
RATE Research ResultsFatal Blow to Billions of Years
| Answers in Genesis
These are seemingly powerful evidence, but until these folks are done their research and evolutionist have been given the chance to confirm this, most of this is debatable.
This is just exciting news for creationists and gives us( for those Christians who need it) more reason to doubt evolutionists when they oppose the Bible.