Surely it would depend on what the simulation actually was?
If you imagine simulations we can build ourselves, such as video games, it's not hard to add something at the edge of the map that users are prevented from reaching and have the code send "this thing is massive and powerful" data to the players. Who's to say that the simulation isn't actually focussed on earth, and everything including the sun is actually just a fiction designed to fool us?
The common trait that all hypothetical high-fidelity simulated universes possess is the ability to produce high-fidelity simulated universes. And since our current world does not possess this ability, it would mean that either humans are in the real universe, and therefore simulated universes have not yet been created, or that humans are the last in a very long chain of simulated universes, an observation that makes the simulation hypothesis seem less probable.
If we're a simulation of a parent universe that is exactly like us just of it's past or an alternate past, then we likely should be able to achieve simulating our own universe within ourselves. Otherwise we're not actually a simulation.
There's another line of counter argument that various results in QM and computing theory would suggest that it's mathematically impossible for the universe to be simulated on a computer (i.e. the parent universe would have to look very different from ours vs ours in the future). But I don't recall the arxiv paper.
Of course it is. Scientifically the simulation “hypothesis” is actually the simulation idea and isn’t scientifically valid yet seems to be treated as such for some reason.
For me the interesting thing is, assuming miny worlds AND simulation theory are both true. Many worlds would seem to be a way to essentially run a/b tests on the simulation. So how would you separate out/simplify details of your simulation like far away planet stars and galaxies? The speed of light and light cones, don't seem to be enough to make a difference except for on the largest scales.
If you imagine simulations we can build ourselves, such as video games, it's not hard to add something at the edge of the map that users are prevented from reaching and have the code send "this thing is massive and powerful" data to the players. Who's to say that the simulation isn't actually focussed on earth, and everything including the sun is actually just a fiction designed to fool us?