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 of the probabilities of alternative histories. These are the action functional of the elementary particles, the quantum initial condition of the universe, and the information about our specific history. We discuss the origin of the "quasiclassical domain" 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 emergent after the Planck time because of the character of the specific initial condition and dynamics of our universe.