On 8/20/18 2:02 PM, Phillip Helbig (undress to reply) wrote:
In article ,
writes:

Ie: Can these very similar values all have a common origin--perhaps in the
mutual spin and tidal interactions of the Earth-Moon-Sun system? The usual
driver for mantle (and plate) motion is said to be due to the heat flow and
the local geochemistry of the Earth's interior, and of course the decay of
several radionuclides. Ie: Is this similarity between (1, 2) and (3)
merely a quirky coincidence? Or, over billions of years, have all three
processes achieved some mutual energetics 'partitioning' balance?

[[Mod. note -- It's a coincidence. -- jt]]

Earth core heating can be stated as an effect of Sun/Earth/Moon
gravity tidal effects.

That certainly plays a role. However, the Earth is heated by
radioactivity to a significant extent as well.
Lord Kelvin(1824 - 1907) did not have the radioactivity concept
available to him
(he did not believe Marie Curie's 1867- 1934 radioactivity)
and thermodynamically predicted the earth's age at 20-200 million years
(off by factor of thousands).
RDS