  In what respect does terrestrial physics reflect the two unique features of
the global gravitational field: its infinite range and its equivalence to
spacetime curvature? We quote the evidence that true irreversibility, i.e the
growth of the Boltzmann entropy of any finite system, is the consequence of the
global state of the gravitation dominated and expanding universe. Moreover, as
another example, we calculate the effect of global expansion and of the
gravitational potential observed in our Local Group on spacetime metric in
terms of curvature. Surprisingly, we find an energy density which is in
numerical agreement with the purely quantum theoretical result for the Casimir
energy density containing Planck's constant.
