In the thread Intrinsic heating of white dwarfs, I mentioned that the central idea mentioned there was published in a paper of mine dealing with the expanding Earth theory. That paper has now become available online here. The basic idea is that gravitational potential energy is recycled slowly over time at a rate proportional to the Hubble constant H. In the process heat is given off at the rate:
dE/dt = -UH,
where U is the gravitational potential energy. There is no change in the gravitational constant G itself. In the paper I suggest that for the Earth about 5-10 per cent of the released energy appears as radiated heat and 90 per cent goes into expansion.
I would be curious to get the reactions of the BAUT members to this idea. In regard to the white dwarfs, I've found that the same general relationship holds as far as luminosity is concerned. That is, about 10 per cent or so of the released energy appears as radiant energy. This is a completely different explanation of white dwarf luminosities than the conventional one, which links luminosities mainly to age. The expansion of white dwarfs is more difficult to measure, but as Nereid pointed out in the other thread, it should be measurable as rotational slowing in neutron stars.