The last stars will burn out in 120 trillion years
We think. We still haven’t solved things like the dark matter/energy problem. The answer to that alone could drastically change what we estimate will happen in the distant future.
Stuff only burns for so long. We might learn more about the geometry of space and that there is more out there at greater distances where maybe even other Big bangs are possible but there is a certain maximum amount of time that a star can exist.
Over the time scales of the life of a proton the maximum variability in the amount of time a star can burn is a rounding error against the scale of numbers needed to express the amount of time it takes for hawking radiation to reduce black holes to ultra long wavelengths of infrared radiation.
Also see Dyson’s Eternal Intelligence:
https://en.wikipedia.org/wiki/Dyson's_eternal_intelligence
Basically, if you assume it’s possible to upload our intelligence to a computer and run it, then you can keep the energy going to run it for a very, very long time. Well past the heat death of the rest of the universe. It depends on running things in an on and off state to conserve energy for trillions of years. Subjectively, the people in there wouldn’t notice that and would simply see their active lifespans go for trillions of years. It’s not clear what the limit would actually be.
It’s something like Zeno’s Paradox. You cut things in half each cycle, but never quite get to zero.
I see someone else is a Kurzgesagt fan https://youtu.be/VMm-U2pHrXE


