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.

Based on these assumptions he at first suggested an age of the Earth of between 100 Ma and 500 Ma.

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).

Of course, the detected variation is no more than 0.2% of the published rates, but this paper is still quite interesting since such a correlation was never suspected before.

If magnetic fluxuations or other influencing forces are strong enough, radiometric decay rates could be much more significantly effected.

There is perhaps no beguilement more insidious and dangerous than an elaborate and elegant mathematical process built upon unfortified premises." - Chamberlain 1899b:224Following the discovery of radioactivity by Becquerel (1896), the possibility of using this phenomenon as a means for determining the age of uranium-bearing minerals was demonstrated by Rutherford (1906).

One year later Boltwood (1907) developed the chemical U-Pb method. By combining Von Weizsacker’s argon abundance arguments with Kohlhorster’s observation that potassium emitted gamma-radiation, Bramley (1937) presented strong evidence that potassium underwent dual decay.

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.

Other factors and basic assumptions must also be considered.