Spectrum wrote:It's interesting how little speculative fiction goes into the future. Most of it is confined to the next 1,000 years or so. IIRC, Niven's "The Ethics of Madness" extends several hundred thousand years into the future. The maximum I know of is Olaf Stapledon's "Last and First Men", whose time scale goes to 5 trillion years in the future (!), and that endpoint is labeled "Apart from accidents Earth would still have been habitable".
Scifi rarely extends more than a few hundred to a thousand years in the future because most scifi is an attempt to portray an updated present rather than a completely divergent future. They want to show how our present universe will have changed, and if you go too far then that becomes impossible.
Doctor Who goes 1e14 years into the future but not in a particularly meaningful or realistic way. With the exception of time travel to Earth's (real) history, most of the Doctor's travels are basically fantasy; they could be set anywhere or anytime.