I will give two examples, one speculative and one based on actual observations: I understand half-life, log base-2 calculations and radiometric decay. These atoms, with an odd number of neutrons, are called isotopes. It is possible that the ratio of daughter to parent substances for radiometric dating could differ in the different minerals. The simplest means is to repeat the analytical measurements in order to check for laboratory errors. That is, in the past, uranium transformed into lead much faster than it does today.
This happens at known rates. The Assumptions of Radiometric Dating In the previous hypothetical example, one assumption is that all the argon was produced from the radioactive decay of potassium How often is it done? It would really be nice if geologists would just do a double blind study sometime to find out what the distributions of the ages are.