In addition to explaining current cosmological theory, the authors speculate on what kinds of life might exist in future eras of the universe.

The authors envision life forms completely different from the biochemical ones of Earth, for example, based on networked black holes.

The time scales treated in the book are sufficiently vast, that, the authors find it convenient to use scientific notation.

As this era continues, the authors hypothesize that protons will begin to decay (violating the conservation of baryon number given by the Standard Model).

Black holes themselves slowly "evaporate" away the matter contained in them, by the quantum mechanical process of Hawking radiation.

By this era, with only very diffuse matter remaining, activity in the universe will have tailed off dramatically, with very low energy levels and very large time scales.

As of November 2013[update], Gregory Laughlin makes the following statement on his web site:[3] A large number of interesting developments have occurred in physics and astronomy since the book was written, and many of these advances have a strong impact on our understanding of how the future will unfold.