Two major apparently unrelated problems, that of the origin of time in the
universe associated with quantum gravity and to the entropy in de Sitter
cosmological models, are found to have their origin in a single physical
phenomenon: the semi-classical tunneling through a classically forbidden region
of the cosmological scale function. In this region there is a mixing of the
states of quantum matter and those of the semi-classical gravity which produces
a thermal mixture of the matter states and hence an "entropy"; this same mixing
effect brings about the conversion of a parametric time variable into a
physical intrinsic time.Comment: 17 pages;, no figure. latex 2e, To appear in Moscow Quantum Gravity
Seminar, June 12-19, 1995, latex correction