Is there a possible way to check dating by radioactive means? Scientists have found three ways that annual layers form and each of them is a cross check on the other:
(a) Tree rings! See
http://www.geo.arizona.edu/palynology/geos462/09dendrochron.html
This web site describes counting tree rings and correlating the resulting count with carbon 14 dates. There is an interesting graph at the bottom of the page at that site showing that the actual account does show some variation from the assumption of absolutly constant production of carbon 14 in the atmosphere. But not by very much! It appears Bristlecone Pine rings have been established back about 10,000 years:
(b) Lake bottom sediments! See
http://www.cio.phys.rug.nl/HTML-docs/Verslag/97/PE-04.htm
This site describes the layers of sediment from a lake in Japan going back 40,000 years. They are able to tell the seasons changing in the lakes by means of the color of the diatoms in the lake.
(c) Ice layers in Greenland! See
http://www.skepticfiles.org/science/pr9357.htm
Ice layers in Greenland are so interesting they continue on today. Annual layers of ice go back as far as 250,000 years in the most recent drillings!
All of these layers are correlated with each other. The ice layers, unfortunately, don't have much organic material for correlating directly with the carbon 14 method, but other correlations are available, such as dust and acid from known volcanoes to verify that indeed the counts really are annual layers.
So that's THREE KINDS of ways of finding an annual layer that goes back more than 6000 or 8000 years, definately showing that the world is older.
It's kind of difficult to imagine anything other than the actual years going by that would make each of these three methods independently come up with the same results. Some people have suggested that following Noah's flood there were a lot of "mini years" simulated by storms and such that would perhaps have caused the sediments in the lake to vary and the ice cores to show extra layers that simulate annual layers. But would those have also made the trees grow extra rings, enough so that the rings seem like whole additional years? Stress like that kind of climate variation would make trees shut down, not grow more than ever!