`Bruno Marchal wrote a 10-point argument about determining whether or not we are simulated by some massive computer. Here is point 9 from that post:`

9) Now, from computer science and logic, startlingly enough perhaps, we can isolate a measure on the 1-person comp histories, and this give us the laws of physics (this is too technical to be put here, and actually I have derived only the logical structure of the probability one, but I got something non trivial and very close to a quantum logic (which can be seen as the logic of the quantum probability one, as von Neumann has shown).

Bruno, I agree with everything in points 1-7 of the post I'm referring to. I think I understand the main thrust of points 8 and 10, but they both depend on the truth of the quoted point 9. I find this point highly dubious, and I'm interested to hear more about why you believe it (or whether I'm actually interpreting it correctly).

Bruno, I agree with everything in points 1-7 of the post I'm referring to. I think I understand the main thrust of points 8 and 10, but they both depend on the truth of the quoted point 9. I find this point highly dubious, and I'm interested to hear more about why you believe it (or whether I'm actually interpreting it correctly).

`Is it your contention that if we start only with the idea of Platonia (which contains all possible computational structures and "events"), and we analyze the structure of all possible 1st-person histories weaving their way through this Platonia, we would see that a majority of them find themselves in universes like the one we currently inhabit, with stars, galaxies, relativity, quantum physics, etc.? I find that extremely hard to believe; there are an infinite number of multi-dimensional cellular-automata worlds that contain nothing like stars, galaxies, or the familiar physics we know, and I don't see any reason to believe that all the 1st-person histories weaving their way through these computational structures (which surely exist in Platonia) have less measure than those that weave through the structures more resembling our own universe.`

`I find it much easier to believe - in fact, it seems almost necessarily true - that, when we analyze the structure of all the 1st-person histories weaving their way through Platonia, we see that virtually all observers observe indeterminacy. This in itself seems like a non-trivial finding. It would be even more non-trivial if one could analyze the structure of the indeterminacy that virtually all 1st-person observers must observe, and find that it is very much like "quantum logic". This seems to be one of your claims, and it certainly seems possible (though I don't know enough yet to judge the issue for myself). However, it's a much further leap to conclude that we can go on to derive "the laws of physics" from the analysis of 1st-person histories weaving their way through Platonia. In the quote above, you acknowledge that you haven't actually done this - "actually I have derived only the logical structure of the probability one, but I got something non trivial and very close to a quantum logic" - but you seem to believe that it can be done. Why?`

`-- Kory`