The idea that the universe is a simulation proceeds as follows:
(1) Person notices that computer simulations are getting increasingly powerful. Maybe we will be able to simulate something like the universe one day which will have life in it.
(2) If simulating the universe is so easy and inevitable, what are the odds that we are at the top level?
The idea in the article would refute the inductive step.
> The idea in the article would refute the inductive step.
No it doesn't. The article describes a proof that it is impossible for a computer to simulate this physical universe with perfect accuracy; but, that's not actually a problem for Nick Bostrom's simulation argument. For the simulation argument to work, you don't need to simulate the universe with perfect accuracy – just with sufficient accuracy that your simulated people can't distinguish it from a real one. And this proof isn't about "ability to simulate a universe to the point the simulated people can't tell that it is a simulation", it is about "ability to simulate a universe with perfect accuracy". So the proof isn't actually relevant to that argument at all.
Please explain how to simulate a universe which is indistinguishable from a simulation but which is not accurate according to the rules of the article.
Does the article propose anything empirically testable?
I mean, suppose we are actually in a computer simulation-what observations could we perform, which according to the rules of this article, would show that we were in one, and not the “real” world?
Addendum: from what I understand, the article’s proof relies on computational quantum gravity having a Gödel sentence. Now, quantum gravity is in practice, as far as we know, experimentally untestable-the distinctive phenomena it predicts only occur at scales far beyond our present technological ability to explore-and who can say if that will ever change. So, is it possible for a computer to simulate humanity as it currently exists, such that the simulated humans couldn’t detect they were simulated? I don’t know; but what I can confidently say, is this research has nothing useful to say about that question, because this is theoretical quantum gravity research, and I’m not aware of any good reason to believe quantum gravity has any relevance to answering that specific question. This research claims to show computers are incapable of simulating aspects of reality which are empirically unavailable to us; even if the research is right, it makes zero difference to the question of whether the actual empirical experiences we do have are simulated or not.
One simulator would just "run the laws of our universe" (I don't care to make that precise, since presently it's a trivial statement, but hopefully it's clear that I mean to distinguish it from running a computer), but then that sort of trivializes the idea of "simulation".
Maybe it's possible for us to create a sub-universe of ours with a quantum computer such that we view the entities as a part of our universe, but the entities cannot be aware of us. (This is the insects at the surface of a pond idea, unaware of the dimension above or below.)
(1) Person notices that computer simulations are getting increasingly powerful. Maybe we will be able to simulate something like the universe one day which will have life in it.
(2) If simulating the universe is so easy and inevitable, what are the odds that we are at the top level?
The idea in the article would refute the inductive step.