[Ieghaehia9]

> If we're in a simulation, you have no basis for drawing conclusions about any of our observations, whether those observations have taken place, whether anything outside of this moment exists, or anything outside your mind, or both.

But then simulation is unfalsifiable. Whatever you observe, the simulation could have paused an arbitrary number of times, or modified you or the environment to an arbitrary degree, hence it's compatible with simulation. Which makes simulation "a difference that makes no difference".

[vidarh]

As macguillicuddy pointed out, the point was that the general concept of simulation is indeed unfalsifiable, and we can only ever hope to falsify very limited subsets. E.g. we can certainly say certain things about what features a simulation must have.

It does however not necessarily make a simulation a difference that makes no difference, because if we're in a simulation it is possible that we are in one where it is possible to falsify the theory that we're not in a simulation.

E.g. we could potentially find bugs that reveal telltale signs we're in a simulation, or outright vulnerabilities. It's even possible we could finds ways of "escaping" the simulation.

The problem of course being that you could well devote a lifetime to it and find nothing and it would tell you nothing about whether we're in a simulation or not, so unless you run into some anomaly that hints at it, it'd seem a rather wasteful pursuit.

In reality, of course, chances are none of us will ever see anything to give us reason to pursue that idea, but it's fun to think about. I write short stories about this subject, and I have a long document with headache-inducing scenarios to write up.

[Ieghaehia9]

>It does however not necessarily make a simulation a difference that makes no difference, because if we're in a simulation it is possible that we are in one where it is possible to falsify the theory that we're not in a simulation.

Since, as you said, there are infinite possible unfalsifiable theories, it's a good idea to avoid them. It's better to deal with them when evidence does appear; otherwise you have an infinite number of them to go through.

> E.g. we could potentially find bugs that reveal telltale signs we're in a simulation, or outright vulnerabilities. It's even possible we could finds ways of "escaping" the simulation.

I'm not sure that's even decidable. Is, say, relativity a glitch in the Matrix or just the way the universe works? Or, to flip the question on its head: do simulations we can construct behave like the real world because the real world is simulated, or just because what we can construct is limited by the world we live in?

I think these outright flaws would have to be very obvious to unambiguously point to simulation. And I can't escape the feeling that the simulation idea is a modern version of Newton's clockwork universe: trying to explain the universe by the metaphors we have available today.

[skissane]

I think Bostrom’s core argument is likely valid - the more ancestor simulations you run, the greater the odds you are actually in one yourself. Now, right now that number is zero, and we don’t know if it will ever rise above zero, and even if one day it does, that day is likely many centuries away. But maybe in 500 or 5000 years time, ancestor simulations will be very numerous, and Bostrom’s argument may convince many people in such a scenario

Unfalsifiable propositions can be true, and it is even possible to have good reason-whether direct or indirect evidence-for believing one

“Somewhere and somewhen in this universe there exists an extremely controversial and very famous politician named Donald Trump” is an example of a proposition which is true, and we have very good reason to believe is true, but which is strictly speaking unfalsifiable, indeed almost inherently so. Even if we suppose our Donald Trump had never been born, we could not rule out the possibility of some very famous and controversial politician having that name (let’s say named by a very similar sequence of sounds) existing on a planet in a distant galaxy. If one accepts a B theory view of time, that proposition has always been true, and was just as true in 5000 BCE as it is today, but nobody back then could have possibly known it was true.

[vidarh]

Exactly.

But it is worth also remembering that Bostroms Simulation Argument is an argument for simulation, not the only one possible.

To me the original point I made was simply that non-determinism can't falsify simulation.

More broadly I believe simulation is unfalsifiable, because the impossibility of proving we have existence in time (our consciousness could exist for only a moment, and we can't tell, because we have access to the past only as memories which could be fake), or that a world outside ourselves exists (our sensory inputs could be fake) means we can say hardly anything about the scale or complexity of a theoretical simulation. Said another way: we don't know even how much of ourselves exists.

That opens the door to a vast set of possible simulation arguments, but also raises the question of whether there is a clear line between simulation and what reality is. E.g. you can imagine a similar set of possible conceptions of a physical reality. If physical reality is that our existence is mere fragmentary moments of parts of a mind, then that would mean any experience we might think we have one day of building simulations would themselves be illusory.

So it's not a given that we can meaningfully tell whether or not a simulation exists even if we one day believe we successfully build one, because the experience of building the simulation might well be the totality of the experience. There's no certainty said simulation ever exists.

Trying to nail down what we can actually infer about this is something we'll struggle with for a very long time.

Even defining in concrete terms what is simulation vs. simply an arrangement of physical reality is unclear (think Hitchhikers Guide to the Galaxy where Earth was a computer)

[skissane]

> because the impossibility of proving we have existence in time (our consciousness could exist for only a moment, and we can't tell, because we have access to the past only as memories which could be fake), or that a world outside ourselves exists (our sensory inputs could be fake) means we can say hardly anything about the scale or complexity of a theoretical simulation. Said another way: we don't know even how much of ourselves exists.

Consider the following argument:

1] If P being true is a necessary precondition for rational thought to exist, we are rationally justified in believing that P is true

2] The general reliability of our memories is a necessary precondition for rational thought to exist

3] Therefore, we are rationally justified in believing that our memories are generally reliable

4] Therefore, our memories are generally reliable

From the general reliability of our memories, the substantial existence of the past trivially follows; does that count as "proving we have existence in time"? And replace the "general reliability of our memories" with "the existence of other minds" to turn the above argument into a proof of the later.

> but also raises the question of whether there is a clear line between simulation and what reality is.

I actually think the simulation hypothesis is a pretty good argument for idealism: if the simulation hypothesis is true, then either materialism is simply false (if one interprets "matter" to mean only the apparent physical matter of this universe), or else its truth is unknowable (if one interprets "matter" to mean the unknowable matter of the substrate universe.) If we cannot know whether the simulation hypothesis is true, how can we know that materialism is true? By contrast, if idealism is true, then minds and their experiences are the most fundamental constituents of reality; whether this universe is a simulation is simply a question about whether there exists another universe containing minds who have the experience of operating a computer simulation which appears to contain minds having particular experiences, where those particular experiences happen to be identical to the set of all experiences had by all minds in this universe. Idealism could be equally true no matter what the answer to that question may be. The ontological status of this universe is completely independent of whether that separate simulating universe happens to exist; in principle, our universe could even be simultaneously simulated by multiple distinct simulating universes.

[GoblinSlayer]

If simulation is unfalsifiable, then it's also unjustifiable.

[vidarh]

Falsifiability does not work that way.

To avoid hypotheses that are unfalsifiable is good practice absent evidence because you can construct an infinite number of such hypotheses. That does not mean that a given unfalsifiable hypothesis can not be true, however, just that pursuing it is generally likely to be a waste of effort.

Asserting that simulation is definitely true absent evidence would be unjustified, but very few people would make that claim, so it's not very relevant.

However the inverse - the hypothesis that we're not in a simulation - is falsifiable by proving that we are in a simulation. And any number of variations over the idea that we might be in a simulation can also be testable and falsifiable in various ways.

The original point of contention was that QM and non-determinism proves we're not in a simulation, however, and that is not a viable way to falsify the hypothesis that we're not in a simulation. The hypothesis that non-determinism proves we're not in a simulation is falsifiable by coming up with a way wherein non-determinism can be accommodated.

If the world the simulator runs in has access to non-determinism this is trivially done by simply forwarding non-determinism into the simulation (many other approaches to attack that hypothesis are possible, e.g. using a additional simulations as oracles to determine if supposedly non-deterministic events would be revealed as such, and use that to pick values that ensures a failure to simulate non-determinism never gets detected, so access to a source of non-determinism is not necessary to falsify that hypothesis either, though it would complicate matters). As such the hypothesis that non-determinism alone proves we're not in a simulation is false.

[GoblinSlayer]

If unfalsifiable simulation is unjustifiable, that's bad, isn't it?

[vidarh]

I have no idea what you're trying to say. Why would it be bad? It makes no sense. All it means is insisting it is true without evidence makes no sense. But nobody here is making that claim.

[GoblinSlayer]

Unjustifiability means unfathomability; unfathomability suggests impossibility. And if simulation theory is impossible, its unfalsifiability is of no help.

[macguillicuddy]

Without wanting to speak on their behalf, I think that's exactly vidarh's point. That simulation is indeed unfalsifiable and therefore mjburgess' conjecture that it's false doesn't hold.

[WJW]

Simulation being unfalsifiable is indeed the main problem with the theory.

[klyrs]

A theory known to be unfalsifiable cannot be conclusively ruled "false." It can only be deemed outside of the realm of science. To make such a strong claim puts one back in the realm of faith in pseudoscience.

I like the word "bullshit." Bullshit isn't necessarily true, isn't necessarily false, it's simply not worth my time to wade into it.

[GoblinSlayer]

The simulation theory rests on a hypothesis that there are certain conditions outside of simulation, but if external conditions are certain, then the simulation has limited flexibility and is thus falsifiable. For it to be unfalsifiable external conditions must be at least unfathomable, which takes away the premise of the simulation theory that it correctly guessed external conditions.

[vidarh]

Is sounds like you're discussing a specific simulation hypothesis. I'm assuming you're referring to Bostrom's Simulation Argument, but that is only one possible variant of simulation. Bostrom's Simulation Argument posits that one of three propositions are likely to be true, of which only one posits that we're likely in a simulation. The "simulation proposition" of the argument could be falsified by e.g. humanity going extinct (proving the first proposition of the argument true, but the 3rd - the simulation one - to be false).

But falsifying that proposition would not falsify the notion of simulation.