I dunno, I think we could be in a simulation. I can't imagine any reason we couldn't be, personally. There are certainly specific simulation hypotheses I actively disbelieve in; no, History channel, we are not in a simulation created by our descendants, I love strange loops but that's just dumb. (I know they meant the descendants of the former humanity that we are currently simulating but let me give Ancient Aliens sh*t. Surprise this was a fiction opinion too!!)
But I also don't really care if I'm in a simulation? Well, knowing could be cool, but what I nean is this is reality to me; what I understand "reality" to be is the apparent external world I interact with. I can be convinced something I experience wasn't real in that it doesn't correspond to that external world, like an auditory hallucination (which, I have the charmingly named "exploding head syndrome"); but I can't imagine any experience that involves tossing out that entire world and saying 'oh, no, some other world is the real one' changing my mind. It can be real too, but I can't buy disbelieving in my own level of existence's reality. And if a simulation in my reality had entities that as best I could tell were conscious, I would think of them as real people. So I like when in fiction simulations are treated as real and legitimate in their own way, or where treating them otherwise is shown to be wrong.
There was a Grimoire lore card in Destiny where a research team studying a Vex robot-thingy discovered it was torturing simulations of them. They freed their simulations and cooperated. I think later on that plotline sorta deteriorated but I was pumping my fist so goddamn hard at that part.
I suppose the other thing that marks me out from a general simulation theory believer is that I don't quite buy their math that you are most likely in a simulation. It's contingent on an assumption I don't think I've ever seen mentioned once. Because the idea is that you exist in some universe, so then the prior probability of you being in a simulation is (# of simulated universes that have a 'you' in them)/(# of universes that have a 'you' in them). But this rests on the assumption there is only a finite number of 'unsimulated' universes that could have in them some entity experiencing what you are right now. If that's countably infinite, which seems perfectly possible to me, then we really have two cases: only finitely many simulations with a 'you' in them exist. Congrats, 0% chance you're in a simulation. (It's an infinitesimal chance, not a true 0% since it can still happen, but it happens less often than any real number percent of the time.) If there are countably many simulations, then you have a 50/50 chance of being in a simulation. Doesn't matter if every universe has 1,000,000,000 simulated copies, you have countably infinitely many of both. So you put them in a perfectly one-to-one correspondence with none left out. There are as many even whole numbers as there are whole numbers. Math is fun!
Now if you have countably many 'unsimulated' universes and uncountably many simulations then you get almost certain chance of being in a simulation (100% but it's the counterpart to that infinitesimal 0%) but where the f*ck did they all come from? A simulating computer must take up some space so short of it being infinitely thin you can't cram uncountably many into any one universe, so you're stuck with countability.
Now, under Many Worlds, best I can tell there are uncountably many universes. (That's weird to me, I don't see how, but it seems consistently to be the interpretation.) And presumably then there are either uncountably or countably infinitely many with you in them. (A finite set should immediately balloon via all the possible position eigenstates or whatever; otherwise there'd only be finitely many universes total.) In the uncountable case, the number of simulated universes with you in them is at most the same cardinality, because again any individual universe can't have uncountably many simulated ones coming out of it given our current understanding of physics.
So LessWrong people should believe their personal chance if being in a simulation is, at most, a coin flip. That's significant, but not really the same as almost certain.
