Classical Physics and Hamiltonian Quantum Mechanics as Relics of the Big
  Bang
  In a fundamental formulation of the quantum mechanics of a closed system such
as the universe as a whole, three forms of information are needed to make
predictions for the probabilities of alternative time histories of the closed
system . These are the action functional of the elementary particles, the
quantum istate of the universe, and the description of our specific history. We
discuss the origin of the "quasiclassical realm" of familiar experience and
Hamiltonian quantum mechanics with its preferred time in such a formulation of
quantum cosmology. It is argued that these features of the universe are not
general properties of quantum theory, but rather approximate features that are
emergent after the Planck time as a consequence of theories of the closed
system's quantum state and dynamics.
