Both the physical geologists and paleontologists could point to evidence that much more time was needed to produce what they saw in the stratigraphic and fossil records.As one answer to his critics, Kelvin produced a completely independent estimate -- this time for the age of the Sun.
Interweaving the relative time scale with the atomic time scale poses certain problems because only certain types of rocks, chiefly the igneous variety, can be dated directly by radiometric methods; but these rocks do not ordinarily contain fossils.
Some, like Robert Gentry, have even argued that Radio-halos from rapidly decaying radioactive isotopes in granite seem to indicate that the granites were formed almost instantly.
Later, after radioactivity had been proven to be a significant source of the Earth's internal heat, he did privately admit that he might have been in error.
What is especially telling about this whole story is the conclusion of the absolute truth of the conclusion based on premises that are weak, or at least not adequately demonstrated.
Of course there seem to me to be fairly reasonable explanations for this observation which may allow for more slowly forming granitic rocks.
For instance, polonium radiohalos are sometimes associated with polonium bands generated by the polonium being transported by hydrothermal fluids along fractures.He believed this even though he did admit that some heat might be generated by the tidal forces or by chemical action.However, on the whole, he thought that these sources were not adequate to account for anything more than a small faction of the heat lost by the Earth.But in general, this rate is felt by the vast majority of mainstream scientists to be a fundamental constant. al., published a paper suggesting that the decay rate of radioactive elements is related to the Earth's distance from the Sun.In other words, the decay rates show annual changes that closely reflect the Earth's distance from the Sun (see illustration).Based on these assumptions he at first suggested an age of the Earth of between 100 Ma and 500 Ma.