The way to actually make the universe colder and preserve all the energy currently going to waste in stars is to dump all the matter in your galaxy in two giant spinning black holes, and then extract energy via the Penrose process. There’s no way that a civilisation would just say “oops, we want to use reversible computing, I guess we now have no use for all those stars and giant gas clouds, let’s just leave them be as they are now...”
No offense, but I don’t think you understand the physics/engineering of far future computation even remotely close enough to have anything remotely justifying the insane confidence you’d need to override the prior (as nobody does). As just one example, advanced civs may be able to subtly alter the laws of physics via accumulated acausal trade over the seed params of new universe creation through a bubble nucleation process, and they would always favor new hidden physics which allows for expansion of local compute to continue exponential or hyper-exponential growth. Expanding into the stars is complete stagnation in comparison as it allows only weak polynomial growth.
In other words, you are assuming expansion rather than transcension, and have no possible reasons to justify an extremely high prior against transcension to overcome the update that we indeed to not see the expected evidence of expansion.
The way to actually make the universe colder and preserve all the energy currently going to waste in stars is to dump all the matter in your galaxy in two giant spinning black holes, and then extract energy via the Penrose process. There’s no way that a civilisation would just say “oops, we want to use reversible computing, I guess we now have no use for all those stars and giant gas clouds, let’s just leave them be as they are now...”
No offense, but I don’t think you understand the physics/engineering of far future computation even remotely close enough to have anything remotely justifying the insane confidence you’d need to override the prior (as nobody does). As just one example, advanced civs may be able to subtly alter the laws of physics via accumulated acausal trade over the seed params of new universe creation through a bubble nucleation process, and they would always favor new hidden physics which allows for expansion of local compute to continue exponential or hyper-exponential growth. Expanding into the stars is complete stagnation in comparison as it allows only weak polynomial growth.
In other words, you are assuming expansion rather than transcension, and have no possible reasons to justify an extremely high prior against transcension to overcome the update that we indeed to not see the expected evidence of expansion.