>If physics ranges over the reals
I thought this was ruled out by https://en.wikipedia.org/wiki/Bekenstein_bound
I thought this was ruled out by https://en.wikipedia.org/wiki/Bekenstein_bound
The formal discussion around this is largely centered on the Church-Turing thesis:
https://en.wikipedia.org/wiki/Church%E2%80%93Turing_thesis
Essentially stating (in a certain interpretation) that any physical process can be simulated by a Turing machine (with no mention of efficiency). This seems to be the case, although I'm not sure we have a convincing proof from quantum field theory yet (note that quantum process can be simulated in classical Turing machines, although with an exponential cost).