Heat death, big rip, or big crunch?—what is the ultimate fate of the universe? Here is a timeline of the far future based on various assumptions about the nature of dark energy and speculative processes in astrophysics and fundamental particle physics.
For a more optimistic view of the distant future, see the 2023-08-26 post, “Frank Tipler on the Ultimate Rocket, Ultimate Energy Source, and Ultimate Future”. Prof. Tipler argues that once life appears in the universe, no account of the universe’s future evolution can neglect the actions of intelligent agents intervening in what would otherwise be mindless physical processes. What if we learn to use and control dark matter and energy, just as clever talking apes have harnessed chemical and nuclear energy to remake their home planet?