  As time advances in our perceived real world, existing information is
preserved and new information is added to history. All the information that may
ever be encoded in history must be about some fundamental, unique, atemporal
and pre-physical structure: the bare world. Scientists invent model worlds to
efficiently explain aspects of the real world. This paper explores the features
of and relationships between the bare, real, and model worlds. Time -- past,
present and future -- is naturally explained. Both quantum uncertainty and
state reduction are needed for time to progress, since unpredictable new
information must be added to history. Deterministic evolution preserves
existing information. Finite, but steadily increasing, information about the
bare world is jointly encoded in equally uncertain spacetime geometry and
quantum matter. Because geometry holds no information independent of matter,
there is no need to quantize gravity. At the origin of time, information goes
to zero and geometry and matter fade away.
