Wouldn't this make all the rocks appear the same age?
"The rock question is fairly simple and has to do with the basic elements which made up these rocks in the beginning.
As time progressed each would begin to acquire its slower modern-day stable half-life, but would they all acquire these stable rates in a uniformity which would keep them all in synchrony? If they did, all would give the same ages, you are right.
Each would probably arrive at equilibrium at different times.
So if scientists believe that a creature lived millions of years ago, then they would need to date it another way. They assume dinosaurs lived millions of years ago (instead of thousands of years ago like the bible says).