ABSTRACT
Long periodic geodynamic
processes with durations between 150 and 600 Million years appear to be in
phase with similar galactic cycles, caused by the path of the solar system
through the spiral arms of the Milky Way. This path is assumed by some authors
to cause climate change due to cosmic ray fluctuations, affecting the cloud
formation and the related albedo of the Earth, which periodically lead to glaciations
every 150 Ma. With the glaciations, the sea level fluctuates accordingly.
Subsequently, the varying sizes of shallow seas are causing periodic changes of
the Moon’s tidal dissipation,
which affects presumably other geodynamic processes on the Earth. The Moon may therefore synchronize directly or
indirectly long periodic Phanerozoic cycles (sea level, orogeny, magmatism,
sedimentation, etc.) with the Milky Way. As sea level fluctuations, orogeny,
sedimentation and magmatism can be described as members of a geodynamic
feedback system; no apparent reasons appear to be required to assign a cause of
the cyclicity to agents outside of the galactic-climatically
synchronized Earth-Moon system. However, recent observations of young volcanism on the near Earth
terrestrial planets may require a new understanding. Magmatic/volcanic episodes
on Venus, Mars and Mercury as well as on the Earth’s Moon are apparently
contemporaneous thermal events accompanying increased magmatic/volcanic
activities on the Earth, following a 300 myr cycle. Therefore,
a collateral galactic thermal source within the Milky Way appears to be needed that only affects
the interior of the planets without any recognizable direct effect on life and geology on the
Earth. The search for such a source may lead to astrophysical questions, related to a spiral arm
affected distribution of dark energy, dark matter or even specific neutrino sources. However, all
possible astrophysical answers are outside of the author’s competence.