The property such universes have in common is that they are computable on a hypothetical classical computer with unlimited capacity. (Potentially very inefficiently, like maybe computing one Planck unit of time in a tiny part of the simulated universe would require greater computing capacity than our universe could provide during its entire existence. These are mathematical abstractions unrelated to the real world.)
That implies a few things, for example that in none of these universe you could solve a halting problem. (That there would be certain potentially infinite calculations, whose output you would not be able to predict in limited time.)
But Wolfram’s theory doesn’t provide any benefit here, other than circular reasoning. “If the universe is Turing-complete, then it can be simulated using Wolfram’s latest favorite system, which would imply that it is Turing-complete.” Why not just skip that part?
The property such universes have in common is that they are computable on a hypothetical classical computer with unlimited capacity. (Potentially very inefficiently, like maybe computing one Planck unit of time in a tiny part of the simulated universe would require greater computing capacity than our universe could provide during its entire existence. These are mathematical abstractions unrelated to the real world.)
That implies a few things, for example that in none of these universe you could solve a halting problem. (That there would be certain potentially infinite calculations, whose output you would not be able to predict in limited time.)
But Wolfram’s theory doesn’t provide any benefit here, other than circular reasoning. “If the universe is Turing-complete, then it can be simulated using Wolfram’s latest favorite system, which would imply that it is Turing-complete.” Why not just skip that part?