  Standard calculations suggest that the entropy of our universe is dominated
by black holes, whose entropy is of order their area in Planck units, although
they comprise only a tiny fraction of its total energy. Statistical entropy is
the logarithm of the number of microstates consistent with the observed
macroscopic properties of a system, hence a measure of uncertainty about its
precise state. Therefore, assuming unitarity in black hole evaporation, the
standard results suggest that the largest uncertainty in the future quantum
state of the universe is due to the Hawking radiation from evaporating black
holes. However, the entropy of the matter precursors to astrophysical black
holes is enormously less than that given by area entropy. If unitarity relates
the future radiation states to the black hole precursor states, then the
standard results are highly misleading, at least for an observer that can
differentiate the individual states of the Hawking radiation.
