I’m sorry I can’t divulge information on my client’s secret, illegal universe simulation.
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Oh crap. I shouldn’t have said he was my client.
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Oh crap! I shouldn’t have said it was a secret.
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Oh crap! I certainly shouldn’t have said it was illegal.
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Ah, it’s too hot today.
— With apologies to “The Simpsons”
The OP may be considered funny or whatever, but it touches on a serious problem with the simulation hypothesis IMO.
Bear in mind such simulations are not simulating a whole universe down to the quark; they’re approximating various things, only simulating the things they’re interested in etc.
So then you look at my mundane, repetitive life. Is this part of the simulation that is being simulated for real, with an uncertain outcome?
Is so, why? What would a sentient species find so interesting about my life that they’d simulate me taking showers, going to the gym, moping floors etc over and over and over again?
If not, then that means I have fake memories. And unfortunately fake memories takes us down the solipsism rabbit hole: I would be unable to trust anything, including a previous evaluation of the simulation hypothesis.
I realize this was said seven years ago, but it comes up in this sort of discussion often enough to be worth addressing. The point is, simulating a quantum universe is actually way harder than simulating a classical universe—exponentially harder, in fact: whereas the number of parameters you need to keep track off for a classical world is linear in the number of particles within that world, the number of parameters for a quantum world scales exponentially with the number of particles. The reason for this is exactly the presence of non-factorizing, entangled states that are at the root of Bell inequality violations and the like.
Another way to think about this is the following: if quantum mechanics were easy to simulate classically, then there could be no speedup for quantum computers. Why? Well, if there’s an efficient quantum algorithm for a given task, and an efficient way to simulate arbitrary quantum systems, then there’s an efficient classical algorithm consisting of simply simulating that quantum system performing the efficient quantum algorithm. So at some point, we must hit a bottleneck; and that’s the fact that in general, simulating quantum systems is a computationally hard task.
So if anything, the fact that the world is quantum ought to make us question the plausibility of the simulation hypothesis.
And actually, if we take quantum mechanics at face value, then we know at least that our universe isn’t simulated on a classical universal device: quantum measurement generates (apparently) true random numbers, which is something no classical computer can ever do. Of course, there are ways to fake this—one is to simply use pseudorandom numbers, and ensure a large enough seed; the other is to just output every possible bit string, and ‘branching’ the universe at each point. The vast majority of branches will contain random outcomes, ensuring that the vast majority of entities in the simulation will see genuine randomness; but of course, this gets computationally intractable quickly!
One upshot of this is that if our simulator overlords use the first option, it may be possible to detect this: in principle, if quantum measurement outcomes are pseudorandom, we can use this fact in order to send signals at superluminal speeds.
Player and NPC are not the only possibilities. We may be noise, contamination, or some other unintended effect.
We need to distinguish between what’s being simulated. Is it “a universe”? Like, are they simulating the formation of stars and galaxies, and sure, planets, and sure, some of those planets develop life, but the point is the creation of the universe.
Or are they simulating “Planet Earth”, to some level of detail. Like, maybe they started simulating Earth 4.5 billion years ago and are watching all the dinosaurs and trilobites, and everything outside of the Earth is just a big mock-up, and humans are just another crazy species on this simulated ecosystem.
Or are they simulating human history? So start at 50,000 years ago with the sudden appearance of culturally modern humans.
Or maybe they’re interested in Bob. The universe started when Bob was born, and they’re watching him to see what he does.
In none of these examples should there be such a thing as “players”–that is, entities in our universe controlled by entities in the higher universe. What would that even mean?
And also note that it’s hard for me to see the distinction between “creating a simulated universe” and “creating a universe”. What exactly is the difference between them again?
If you are reading this, you are almost surely an NPC.
Leonardo DiCaprio, laying on beaches, and having sex with supermodels is playing the game.
Trump is playing the game. Once you accept that his character is being played by a 14 year old boy, it all makes sense. All the Sports stars, celebrities, heads of state, etc are all playing the game.
Isn’t there some Indian religion that postulates that all of reality is just some god dreaming?
Maybe Vishnu and hinudism but I thought there was one that was more explicit about the whole dreaming thing.
That make sense. Trump’s player has cheat codes.
We don’t really know this yet–there may be a bound on the allowable degree of entanglement.
If it turns out that we can build arbitrarily powerful quantum computers, then I’d say your claim is true, but no one has done that yet. Our best physics says it should be possible, but perhaps there is some natural noise level that makes extremely powerful QCs impossible. If so, this noise could be there to hide limits on the fidelity of the simulation.
Alternatively, perhaps at the “higher level” it is just the natural state of things that computation scales exponentially, and so quantum simulations are relatively easy. But they still only want to simulate the bare minimum, so our version of QM is designed so that the math can be simplified as long as nothing is measuring the results precisely enough to tell the difference.
We’re all NPCs, and no one is being controlled. But some people have a consciousness “plugged in”. They’re just watching a very advanced, high-fidelity movie. We can’t control the characters in movies we watch, and yet sometimes we get so involved that we feel like we’re the character. And you don’t really care that the movie is utterly deterministic, because when you’re watching it you still don’t know how it ends. It’s the same way for them, except that with access to all the senses, thoughts, and memories of a particular person, the illusion is almost perfect.
We are an anomaly… perhaps the galaxys are partitions, designed to isolate and contain individual experiments/simulations and prevent cross-contamination. Guess I’ll never get to meet ET.
Of course, there always may be something unexpected lurking behind the next corner; but this still means that quantum mechanics isn’t an argument for the simulation hypothesis, as we must suppose it to fail at some certain point to ensure efficient simulation.
We already know that QM must fail since it’s inconsistent with GR, but there are degrees of failing. QM will fail in the same way that Newtonian mechanics failed in the face of SR; it’s still almost perfect in the limiting case, but it gets increasingly inaccurate as you reach some bound.
We know that QM looks almost exactly like classical mechanics as the ensemble size increases (with some exceptions, like superfluids). Which is also kinda what you want for efficient simulation. I guess the point is that QM has several features and the ones that appear difficult (exponential complexity) may not actually be true, while other features that appear convenient (like the EPR paradox) may still hold.
At any rate, a machine that can factor a million digit number into two primes would certainly cast some doubt on this possibility. So it’s at least more falsifiable than string theory :).
Are the little tin ducks at the far end of a shooting gallery NPCs?
While both theories indeed appear inconsistent, few people (in fact, I can only think of Roger Penrose right now) take this as a sign that QM will fail/needs to be modified—certainly, all mainstream proposals for quantum gravity (string theory, LQG) are perfectly ordinary quantum theories. Moreover, the proposal that’s been growing the fastest and attracting the most attention recently sees gravity and spacetime itself as emerging from the entanglement structure of the underlying degrees of freedom—if that should bear out (and I have high hopes that it does), then not only are both theories not inconsistent, but QM always already had GR as a built-in feature.
double post
An NPC is, in my mind, a less well-defined entity, and thus we would not be able to ask the question if we were them.
If you mean “are we being controlled from outside the simulation” then the answer is we’re almost certainly all NPCs. What point is there to allow consciousness to develop and have us continue to function in full capacity when a player isn’t present to observe us?
If we’re a simulation, I would expect it to be a hands off one.