In Stephen Baxter's Time [1], in the far far future, when all the stars have died out and black holes have finally all evaporated, the descendants of mankind ar

In Stephen Baxter's Time [1], in the far far future, when all the stars have died out and black holes have finally all evaporated, the descendants of mankind are left in a maximally entropic universe, with no free enrgy left at all. They are condemned to live in giant simulations powered by reversible computing (consuming no power), reliving the same events over and over again, as computations are uncomputed and then recomputed. [1] https://en.wikipedia.org/wiki/Time_(novel) https://en.wikipedia.org/wiki/Time_(novel)