  Hawking has shown that if black holes were to exist in a universe that
expands forever, black holes would completely evaporate, violating unitarity. I
argue this means unitarity requires that the universe exist for only a finite
future proper time. I develop this argument, showing that unitarity also
requires the boundaries of all future sets to be Cauchy surfaces, and so no
event horizons can exist. Thus, the null generators of the surfaces of
astrophysical black holes must leave the surface in both time directions,
allowing non-spherical topologies for black hole surfaces. Since all
information eventually escapes astrophysical black holes, and since the null
surfaces defining astrophysical black holes are Cauchy surfaces, holography
automatically holds. I further show that unitarity requires the effective
cosmological constant to be zero eventually, since otherwise the universe would
expand forever.
