I’m not sure that you can get to 10^60 years even if protons don’t decay. If they do, then you might not have very much more time than whatever the decay timescale is. It could be that free protons decay while bound ones don’t, in which case you might just avoid having any hydrogen or other light elements around.
Assuming you have a galactic mass available to do with as you please and can extract essentially all of its mass-energy, then over 10^60 years you would have a few picowatts available to do all the maintenance that might be required for whatever infrastructure you have. That’s a pretty miserly budget for managing structures at a scale that can convert galactic mass to usable energy! It would have to cover all sensors as well as computation and also any work that might need doing from time to time. I would be very surprised if maintenance costs didn’t scale along with mass, just because the number of particles enormously expands the state space.
Over these sorts of timescales even the most rigidly bound materials diffuse like a gas due to various quantum processes, but maybe there is some clever way to avoid that and still have them able to perform the desired functions when required.
Anything over these sorts of timescales are going to be very speculative, so this is probably about the best “answer” I can give. In reality, we don’t know what happens to matter over 10^30 year timescales even if the cosmological predictions were spot-on.
It sounds like part of the thing here is “you can spend energy/time/effort re-arranging matter into configurations that will survive longer, but you’ll pay a bunch of costs trying to optimize for that, and it’s not obvious that those costs are worth it.”
(i.e. maybe you can arrange a galaxy to survive as long as possible to output “goodbye, world” with minimum viable sentience at the longest possible timeslot, but, like, do you really wanna sacrifice a bajillion possible flourishing lives so that you can print “goodbye, world” at seventy bajillion trillion years instead of 1 bajillion trillion years?”)
I’m not sure that you can get to 10^60 years even if protons don’t decay. If they do, then you might not have very much more time than whatever the decay timescale is. It could be that free protons decay while bound ones don’t, in which case you might just avoid having any hydrogen or other light elements around.
Assuming you have a galactic mass available to do with as you please and can extract essentially all of its mass-energy, then over 10^60 years you would have a few picowatts available to do all the maintenance that might be required for whatever infrastructure you have. That’s a pretty miserly budget for managing structures at a scale that can convert galactic mass to usable energy! It would have to cover all sensors as well as computation and also any work that might need doing from time to time. I would be very surprised if maintenance costs didn’t scale along with mass, just because the number of particles enormously expands the state space.
Over these sorts of timescales even the most rigidly bound materials diffuse like a gas due to various quantum processes, but maybe there is some clever way to avoid that and still have them able to perform the desired functions when required.
Anything over these sorts of timescales are going to be very speculative, so this is probably about the best “answer” I can give. In reality, we don’t know what happens to matter over 10^30 year timescales even if the cosmological predictions were spot-on.
It sounds like part of the thing here is “you can spend energy/time/effort re-arranging matter into configurations that will survive longer, but you’ll pay a bunch of costs trying to optimize for that, and it’s not obvious that those costs are worth it.”
(i.e. maybe you can arrange a galaxy to survive as long as possible to output “goodbye, world” with minimum viable sentience at the longest possible timeslot, but, like, do you really wanna sacrifice a bajillion possible flourishing lives so that you can print “goodbye, world” at seventy bajillion trillion years instead of 1 bajillion trillion years?”)
And, well, that’s fair I guess.