Wolfram Physics Q&A

Yes, in principle the rules for the universe could simply no longer apply to any part of the spatial hypergraph. If this situation occurred, it would mean that time would no longer progress, and the universe would reach a final state, or fixed point, in effect giving the final result of the computation that corresponded to its evolution. Given that the universe probably has 10³⁰⁰ or more elements, behaving in a computationally irreducible way, it seems absolutely inconceivable that everything could effectively “line up” to reach a fixed point. If this were to happen, however, then it would imply that the evolution of the universe could be summarized with much less computational effort than actually doing the evolution, or, in other words, that the universe is not ultimately capable of full universal computation.