Sorry, it's wikipedia. Best I could do at the time. All radio dating is based on assumptions that decay rates are indeed constant, that their formulas accurately extrapolate decay rates to begin with, that they have an accurate theory for how a particular rock or mineral was formed, that conditions under which the rock or mineral have existed have been constant, etc, etc, etc.
I read a new theory about how the moon was formed when an object struck the earth with such force that both basically became whirling balls of plasma for a few hundred years or so until they cooled enough to become rock again. This theory explains how the moon is mineralogically identical to the earth. Pretty interesting stuff. Do I believe it? Don't know.
I'm not saying all math and science are useless. I believe they are at least true enough to be of utility. But one needn't feel the need to form a concrete world view around any particular theory, or groups of theories.