I know, “if an ancestor simulation is possible than it is much more likely you’re in one than not in one.” That’s fallacious, unfalsifiable and everyone loves to leave out the word “ancestor” which is very important to the thought experiment.
In our universe, no system is entirely isolated from the rest of it. It is impossible to create a system that does not in some way interact with the outside universe. So if it is a simulation in a universe, and the universe it is running in also has this rule we would see information from that universe leak into ours in some way. How that would appear we don’t know, but it would be possible to figure it out. Maybe heat dissipates out, maybe bit flips happen in our universe due to the parent’s equivalent to cosmic rays, maybe the speed of light is a result of the clock speed of the simulator. We don’t know what it would be, but there would be something, and it would be theoretically discernible.
at least some of the laws of our universe are laws of the parent universe. So maybe that rule, no system exists in isolation, is also true above. Or maybe our speed of light is the same for them. Whatever it is, our cumulative constraints are more than that of the simulation.
All that, unless, in the parent universe, 1) systems can exist in isolation, or 2) it is an environment with no constraints. These two are functionally equivalent, so I’ll talk about them like they’re the same thing. In such a universe, there would be no causality, no form, nothing that makes it unified. It’s not a universe at all. It’s something like a universe post heat death. In such a scenario, running a simulation isn’t possible. If it were, to create an environment in which causality can be simulated, that environment wouldn’t be a simulation, it would be a bona fide universe.
So I think, the fact that we see no evidence that we are in a simulation means we are probably not in one. So that means, if we are in one it is falsifiable and we can prove or disprove it empirically. And it also means we can escape, or at the very least destroy it.