  We discuss the large-scale structure of the universe in inflationary
cosmology and the implications that it may have for the long-term future of
civilizations. Although each civilization is doomed to perish, it may be
possible to transmit its accumulated knowledge to future civilizations. We
consider several scenarios of this sort. If the cosmological constant is
positive, it eventually dominates the universe and bubbles of inflationary
phase begin to nucleate at a constant rate. Thermalized regions inside these
inflating bubbles will give rise to new galaxies and civilizations. It is
possible in principle to send a message to one of them. It might even be
possible to send a device whose purpose is to recreate an approximation of the
original civilization in the new region. However, the message or device will
almost certainly be intercepted by black holes, which nucleate at a much higher
rate than inflating bubbles. Formation of new inflating regions can also be
triggered by gravitational collapse, but again the probability is low, and the
number of attempts required for a positive outcome is enormous. The probability
can be higher if the energy scale of inflation is closer to the Planck scale,
but a high energy scale produces a tight bound on the amount of information
that can be transmitted. One can try to avoid quantum tunneling altogether, but
this requires a violation of quantum inequalities which constrain the magnitude
of negative energy densities. However, the limits of validity of quantum
inequalities are not clear, and future research may show that the required
violation is in fact possible. Therein lies the hope for the future of
civilizations.
