Isn't it obvious for most that for an advanced enough simulation, it is impossible to prove that you are in a simulation from inside the simulation? Even if we find proof that our current model of reality is wrong, it would only mean we need to search for another model of reality, we can't just say "but out theory doesn't actually match the reality because the reality is actually a simulation that computes approximations for some cases".
Imagine if Einstein thought something (let's say for the sake of argument that he had access to some real close-to-speed-of-light experiments): "classical mechanics, isn't wrong, but predictions for close-to-the-speed-of-light experiments don't match the reality because we live in a simulation and the resource constraints forced by the computations needed for the simulation computer to do for such cases make it distort things through heuristic approximations ...and because we live in a simulation I can further pursue my other line of work, the genetic theory of Leprechauns and Fairies...".
Now I actually believe the plausability of the simulation theory, unfalsifiable as it may be, and all, but I think such simulations wouldn't be run for "fun" alone: if we're in a simulation, we're either (a) "babies" in nursery that probably involve multiple existences in multiple simulations until we are "prepared" for the "top-level reality" or (b) we and our universes are a very advanced form of... future "bitcoin miners" :| (I sincerely hope for either (a) or the plain ol "reality is real" theory, but one can never now...)
I think the experiment as designed could show you that you are inside a simulation, but would make it hard to show you were real.
Think about time-lapse photography and simulated photons. As we get better at doing time-lapse photography (more FPS), we might see movement along the predicted course become step-wise (rather than a smooth function). Barring some weird physical phenomena, this could show we were inside a simulation.
But it's also possible that the simulation's FPS is far higher than what we can ever measure. That doesn't make it any less a simulation, but we also can't assume it's reality.
And if it has? Well, then the statistical likelihood is that we're located somewhere in that chain of simulations within simulations. The alternative - that we're the first civilisation, in the first universe - is virtually (no pun intended) absurd.
wrong. there are multiple alternatives; we are the nth civilization in a real universe, we are the nth to the nth civilization in the multiverse, etc. Sloppy sensationalism and bad statistical reasoning in this article.
I've always felt there's something deeply fallacious -- or hopelessly wrapped up in human psychology -- about taking a representation of a virtual world that we might create and treating it as on par with the actual universe.
It's almost like saying "we're probably characters in a novel," since for every universe there are many novels. Or like that old proof that God exists because he has every desirable quality, including existence -- as if a hypothetical entity could be forced into being by sheer burden of how it is described.
When we talk and reason, we call something a universe to invoke all the general properties our universe has -- except existence, of course, because it would be silly if we could only talk about things that exist. Various things like books and simulations are physical representations of universes that don't exist. By virtue of our interpretation, they are universes nonetheless. When reading a book, we fill in assumptions and details from real life if the author gives us no reason to think otherwise. Tautologically, the world of the book is different from the real world in some limited and structured way, but not in any way that keeps it from being a world at all.
Physics seeks to explain the world exhaustively and reductionistically in terms of mechanisms, models, and mathematics -- basically, to boil it all down to the consequences that emerge from laws and equations that we can completely conceptualize. If the universe consisted just of electromagnetism, for example, then Maxwell's equations would be a "complete" description of the universe, and any simulation of them could be considered a universe. Everything about the universe, every general description that's true of it without reference to specific places, times, and things, would be reflected in the simulated universe as well, because science allows us to subsume it all into the more fundamental description given by the equations.
The problem is that a model of the universe is stil a model. Humans invented the notion that a thing and a description of a thing are equivalent.
Anyway, your objection here isn't actually relevant as far as I can tell. It's a probabilistic argument about the number of real minds vs. the number of simulated minds, and the bulk of the "proof" is in demonstrating that, under certain assumptions, the number of simulated minds would be so high in comparison to the number of real minds that you'd almost be forced to conclude that you are simulated.
It really doesn't have anything to do with "universes inside universes."
A provoking question: if we found evidence that convinced us, beyond a reasonable doubt, that we were living in a computer simulation, would you change your behavior?
Bostrom's postulates are exceedingly bad. His assumptions rely to much on the isotropy of properties of the one "real" existence and the simulated ones. I would expect, statistically, that there would be far more universes simulated that have properties that are nothing like the "real" one as technology progresses, i.e. there are more instances of "sonic the hedgehogs" and "super mario brothers 1" over the more "realistic" call of duty. It follows that if our universe is one of the more probable universes that our laws of logic and probability estimates are not calculated from probable postulates, thus our assumptions leading to any conclusion are probably in error.
"The theory basically goes that any civilisation which could evolve to a 'post-human' stage would almost certainly learn to run simulations on the scale of a universe. And that given the size of reality - billions of worlds, around billions of suns - it is fairly likely that if this is possible, it has already happened."
That sounds distinctly like Anselm's ontological proof for the existence of God, and thus likely suffers from the same logical fallacies.
If you want to take on a non-strawman version of the argument, check out benhammer's links below.
That said, I do often feel that at the literal edges of our universe (in all the senses of that term), our uncertainties simply dominate everything and all of our guesses about the true nature of reality are dominated by that uncertainty. Something (or, depending, multiple somethings) must be true for some value of true, but I'm skeptical if we can discover it. If it popped up and simply flat-out told us what the truth was somehow (the Great Simulator writing the message in the stars [1]), we probably couldn't confirm it.
Well the most interesting part of the Matrix trilogy was when Neo used his powers in the 'real' world; specifically stopping the drones and being able to see despite losing his eyesight.
Anselm defined God as "that than which nothing greater can be conceived", and then argued that this being could exist in the mind. He suggested that, if the greatest possible being exists in the mind, it must also exist in reality. If it only exists in the mind, a greater being is possible—one which exists in the mind and in reality.
What are the specific parallels you see, beyond them both sounding specious?
The simulation argument says: if simulating minds is possible, and technologies eventually advance to the point that they can do it, a civilization would make lots of them. Thus, most minds are virtual, so your mind has a high base rate of being one.
Anselm's argument is: the best thing in the world would have to exist, since existence is better than non-existence. I define God as the best thing, so God must exist.
I don't quite see the parallel, but if you see something specific, I'd like to hear it.
I think it's a bit silly to try to infer things about the computer that could be simulating our universe based on things internal to the simulation. Many of our fictions don't have the same laws of physics as we do.
It's a hypothesis - namely, that the entities running the simulation are trying to simulate their own universe to make deductions and discoveries about it.
Therefore, our universe would be a reasonable facsimile of there's in most respects.
Which has the implication that their may be limitations on their computational substrates which required workarounds or optimizations, or as the lattice QCD case points out - which require representing phenomenoma as discrete computational steps, rather then continuous analytical functions. It's a well known problem in all the computational disciplines, that changing the time-step of your simulation frequently leads to wildly different results then you expect.
Think about the speed of light and tell me how it makes _any_ sense that time slows down due to velocity. Yet that's exactly what EVE Online does to stop nodes crashing during heavy gameplay.
“There is a theory which states that if ever anyone discovers exactly what the Universe is for and why it is here, it will instantly disappear and be replaced by something even more bizarre and inexplicable.
There is another theory which states that this has already happened.”
― Douglas Adams, The Restaurant at the End of the Universe
"Abstract. I think there's a small but non-negligible probability that humans or their descendants will create infinitely many new universes in a laboratory. Under weak assumptions, this would entail the creation of infinitely many sentient organisms. Many of those organisms would be small and short-lived, and their lives in the wild would often involve far more pain than happiness. Given the seriousness of suffering, I conclude that creating infinitely many universes would be infinitely bad."
I've always thought that quantum theory provided some decent evidence for this. Instead of always computing every value for every result, the universe does so only when things are "observed", saving on computation.
No, it doesn't really work that way. A wavefunction is based upon a configuration space and you can't just neglect part of it or you'll get inaccurate results.
Reminded me of an excerpt of "La Révolution des fourmis" ("The Revolution of the Ants", 1996) by the french writer Bernard Werber, in which students run such a simulation (named InfraWorld), until "simulated scientists" uncover the truth of their condition, leading to mass hysteria and eventually the collapse of their civilization...
I've always been interested by this sort of stuff (as I'm sure several people are -- especially the HN audience). It always brings up a bunch of interesting questions:
- If we're self aware of the simulation, would we be able (or ever want to) reverse engineer the fabric of which makes up our sim?
- Would there be infinite simulations? How far _up_ does the rabbit hole go?
- Another idea, and this is reaching, would be to consider the motivation behind running simulations like these. Are the "controllers" running simulations to try and find solutions to problems they are facing? Of course, this is the stuff right out of Scifi movies.
The problem with this theory (the universe is a simulation) is that it's a tautology. You cannot prove or disprove it, and for practical reasons it changes nothing if you assert it's true.
What is really being researched is whether the universe is computable, because that's something you can prove.
If we were created like this, wouldn't it be feasible to say that the creators could just patch this up so the experiment will appear to work but is indeed, rigged.
If someone is running our universe as a simulation they still don't necessarily know of our existence. I have a hard time figuring out how you'd detect intelligent life or its byproducts in your simulation. Even if you do detect something alive, how do you interact with it in a non-destructive way? Also not trivial at all :) That "long-distance phone call" might be far less likely than us ever figuring out if we're indeed a simulation.
Am I right in my (very limited) understanding that they derive their 'observables' (i.e. indicators that would prove we are inside a simulation) from the assumption that the space-time continuum is discretized in a certain way?
By the time we are actually able to perform a simulation on such a scale would the numerical method not have evolved as well and possibly produce totally different kinds of 'observables'?
What I would like to discuss is what purpose would simulating a universe have for the advanced civilisation?
As the civilisation becomes closer to being capable of creating a perfectly simulated universe, they get less benefit from having one. If we assume the universe we are in is at least similar to 'the first', then the existence of entropy / thermodynamic laws would surely create a significant cost to universe simulation. So I can't see it being done without good reason (eg as a toy), and as the master would have to understand all the factors involved in the universe already to create the simulation, so what would they gain?
Is it right to say that it would be impossible to simulate the universe at full speed? (ie. the computer would need to be powerful enough to simulate itself and more (ie. the rest of the universe)). If so, this would not only make it less useful, but put significant (increasing) limits on the local age of the descendent universes; assuming (fairly, i think) that the master universe does not have an infinite existence with infinite time between shocks. Also, how would it be possible to store all the information for a universe within itself?
Or perhaps we are talking about imperfect simulations, which would make it much more feasible? but then the infinite exponential chain would not be possible as each child would become more crude. Or perhaps only a (diminishing) proportion of space(-time) is simulated.. or maybe the speed of light decreases as simulation levels get deeper?
In writing this I think I have come to the conclusion that it is impossible (in so far as anything is given our imperfect knowledge), at least a complete universe simulation or an endless chain, but I would love for someone to show otherwise.
"What I would like to discuss is what purpose would simulating a universe have for the advanced civilisation?"
The Douglas Adams-style answer would be that we're some kid's physics homework. Perhaps, in a sufficiently advanced civilization, building a working computer model of an advanced universe is child's play.
An alternative is that the simulators inhabit a very different universe from our own, and that our simulation is something entirely new. It's not a replica of their universe; it's a completely different creation. They could be studying various scenarios, of which ours is just one.
We need to bear in mind that we're approaching this problem from our own, subjective understanding of our universe. It's not a given that the simulators' universe is anything like ours.
You started this post asking one question, and ended it asking a different (IMO much more interesting) question.
To the first one though, so long as politics and war exist, there would always be reason to attempt to run simulations, regardless of the degree of advancement of a civilization.
By the By, Iain Banks plays around / has a recurring thread of simulations and high powered computers in his culture series, if you enjoy sci fi.
[+] [-] nnq|13 years ago|reply
Imagine if Einstein thought something (let's say for the sake of argument that he had access to some real close-to-speed-of-light experiments): "classical mechanics, isn't wrong, but predictions for close-to-the-speed-of-light experiments don't match the reality because we live in a simulation and the resource constraints forced by the computations needed for the simulation computer to do for such cases make it distort things through heuristic approximations ...and because we live in a simulation I can further pursue my other line of work, the genetic theory of Leprechauns and Fairies...".
Now I actually believe the plausability of the simulation theory, unfalsifiable as it may be, and all, but I think such simulations wouldn't be run for "fun" alone: if we're in a simulation, we're either (a) "babies" in nursery that probably involve multiple existences in multiple simulations until we are "prepared" for the "top-level reality" or (b) we and our universes are a very advanced form of... future "bitcoin miners" :| (I sincerely hope for either (a) or the plain ol "reality is real" theory, but one can never now...)
[+] [-] ritchiea|13 years ago|reply
Even advanced societies will have crappy programmers.
[+] [-] polymatter|13 years ago|reply
[+] [-] pagejim|13 years ago|reply
Found this : http://stackoverflow.com/questions/154163/detect-virtualized...
Whether something like this exists for our virtualized environment, we have to find out.
[+] [-] smoyer|13 years ago|reply
Think about time-lapse photography and simulated photons. As we get better at doing time-lapse photography (more FPS), we might see movement along the predicted course become step-wise (rather than a smooth function). Barring some weird physical phenomena, this could show we were inside a simulation.
But it's also possible that the simulation's FPS is far higher than what we can ever measure. That doesn't make it any less a simulation, but we also can't assume it's reality.
[+] [-] aswanson|13 years ago|reply
wrong. there are multiple alternatives; we are the nth civilization in a real universe, we are the nth to the nth civilization in the multiverse, etc. Sloppy sensationalism and bad statistical reasoning in this article.
[+] [-] dgreensp|13 years ago|reply
It's almost like saying "we're probably characters in a novel," since for every universe there are many novels. Or like that old proof that God exists because he has every desirable quality, including existence -- as if a hypothetical entity could be forced into being by sheer burden of how it is described.
When we talk and reason, we call something a universe to invoke all the general properties our universe has -- except existence, of course, because it would be silly if we could only talk about things that exist. Various things like books and simulations are physical representations of universes that don't exist. By virtue of our interpretation, they are universes nonetheless. When reading a book, we fill in assumptions and details from real life if the author gives us no reason to think otherwise. Tautologically, the world of the book is different from the real world in some limited and structured way, but not in any way that keeps it from being a world at all.
Physics seeks to explain the world exhaustively and reductionistically in terms of mechanisms, models, and mathematics -- basically, to boil it all down to the consequences that emerge from laws and equations that we can completely conceptualize. If the universe consisted just of electromagnetism, for example, then Maxwell's equations would be a "complete" description of the universe, and any simulation of them could be considered a universe. Everything about the universe, every general description that's true of it without reference to specific places, times, and things, would be reflected in the simulated universe as well, because science allows us to subsume it all into the more fundamental description given by the equations.
The problem is that a model of the universe is stil a model. Humans invented the notion that a thing and a description of a thing are equivalent.
[+] [-] nilkn|13 years ago|reply
http://www.simulation-argument.com/simulation.pdf
Anyway, your objection here isn't actually relevant as far as I can tell. It's a probabilistic argument about the number of real minds vs. the number of simulated minds, and the bulk of the "proof" is in demonstrating that, under certain assumptions, the number of simulated minds would be so high in comparison to the number of real minds that you'd almost be forced to conclude that you are simulated.
It really doesn't have anything to do with "universes inside universes."
[+] [-] benhamner|13 years ago|reply
A provoking question: if we found evidence that convinced us, beyond a reasonable doubt, that we were living in a computer simulation, would you change your behavior?
[+] [-] aswanson|13 years ago|reply
[+] [-] brodney|13 years ago|reply
[+] [-] marblar|13 years ago|reply
[+] [-] pizza_|13 years ago|reply
[deleted]
[+] [-] JackFr|13 years ago|reply
That sounds distinctly like Anselm's ontological proof for the existence of God, and thus likely suffers from the same logical fallacies.
[+] [-] jerf|13 years ago|reply
That said, I do often feel that at the literal edges of our universe (in all the senses of that term), our uncertainties simply dominate everything and all of our guesses about the true nature of reality are dominated by that uncertainty. Something (or, depending, multiple somethings) must be true for some value of true, but I'm skeptical if we can discover it. If it popped up and simply flat-out told us what the truth was somehow (the Great Simulator writing the message in the stars [1]), we probably couldn't confirm it.
[1]: http://lesswrong.com/lw/qk/that_alien_message/
[+] [-] batgaijin|13 years ago|reply
[+] [-] klipt|13 years ago|reply
Pretty sure under our current understanding of physics, it's impossible to simulate a universe like our own within our own.
[+] [-] tantalor|13 years ago|reply
http://en.wikipedia.org/wiki/Ontological_argument
(no comment, just providing context)
[+] [-] SilasX|13 years ago|reply
The simulation argument says: if simulating minds is possible, and technologies eventually advance to the point that they can do it, a civilization would make lots of them. Thus, most minds are virtual, so your mind has a high base rate of being one.
Anselm's argument is: the best thing in the world would have to exist, since existence is better than non-existence. I define God as the best thing, so God must exist.
I don't quite see the parallel, but if you see something specific, I'd like to hear it.
[+] [-] endtime|13 years ago|reply
[+] [-] XorNot|13 years ago|reply
Therefore, our universe would be a reasonable facsimile of there's in most respects.
Which has the implication that their may be limitations on their computational substrates which required workarounds or optimizations, or as the lattice QCD case points out - which require representing phenomenoma as discrete computational steps, rather then continuous analytical functions. It's a well known problem in all the computational disciplines, that changing the time-step of your simulation frequently leads to wildly different results then you expect.
Think about the speed of light and tell me how it makes _any_ sense that time slows down due to velocity. Yet that's exactly what EVE Online does to stop nodes crashing during heavy gameplay.
[+] [-] aswanson|13 years ago|reply
[+] [-] joezydeco|13 years ago|reply
[+] [-] GhotiFish|13 years ago|reply
[+] [-] ctdonath|13 years ago|reply
[+] [-] kstenerud|13 years ago|reply
As opposed to us simply being some other civilization on one of the other billions of habitable planets in that same "first" universe?
[+] [-] adventured|13 years ago|reply
[+] [-] lifthrasiir|13 years ago|reply
[+] [-] lucb1e|13 years ago|reply
[+] [-] hcarvalhoalves|13 years ago|reply
"Physicists to Test if Universe is Computable"
[+] [-] tantalor|13 years ago|reply
I think the question is whether the compution is discrete (i.e., cheats) or is everywhere continuous.
[+] [-] devb|13 years ago|reply
http://www.utilitarian-essays.com/lab-universes.html
"Abstract. I think there's a small but non-negligible probability that humans or their descendants will create infinitely many new universes in a laboratory. Under weak assumptions, this would entail the creation of infinitely many sentient organisms. Many of those organisms would be small and short-lived, and their lives in the wild would often involve far more pain than happiness. Given the seriousness of suffering, I conclude that creating infinitely many universes would be infinitely bad."
[+] [-] qu4z-2|13 years ago|reply
[+] [-] Houshalter|13 years ago|reply
[+] [-] sramsay|13 years ago|reply
Time Cube! These stupid idiots still don't understand it.
[+] [-] nate_martin|13 years ago|reply
[+] [-] Xcelerate|13 years ago|reply
[+] [-] marcosdumay|13 years ago|reply
The problem is that this is human bias. You can describe any theory by information manipulation, and it is as good a description as any other.
[+] [-] aswanson|13 years ago|reply
[+] [-] Aldream|13 years ago|reply
[+] [-] darxius|13 years ago|reply
- If we're self aware of the simulation, would we be able (or ever want to) reverse engineer the fabric of which makes up our sim?
- Would there be infinite simulations? How far _up_ does the rabbit hole go?
- Another idea, and this is reaching, would be to consider the motivation behind running simulations like these. Are the "controllers" running simulations to try and find solutions to problems they are facing? Of course, this is the stuff right out of Scifi movies.
[+] [-] hcarvalhoalves|13 years ago|reply
What is really being researched is whether the universe is computable, because that's something you can prove.
[+] [-] mflindell|13 years ago|reply
[+] [-] dllthomas|13 years ago|reply
Would? If they could, they might, or they might be pleased we figured it out :-P
[+] [-] upquark|13 years ago|reply
[+] [-] martijn_himself|13 years ago|reply
By the time we are actually able to perform a simulation on such a scale would the numerical method not have evolved as well and possibly produce totally different kinds of 'observables'?
I realise I am totally out of my depth here :).
[+] [-] polshaw|13 years ago|reply
As the civilisation becomes closer to being capable of creating a perfectly simulated universe, they get less benefit from having one. If we assume the universe we are in is at least similar to 'the first', then the existence of entropy / thermodynamic laws would surely create a significant cost to universe simulation. So I can't see it being done without good reason (eg as a toy), and as the master would have to understand all the factors involved in the universe already to create the simulation, so what would they gain?
Is it right to say that it would be impossible to simulate the universe at full speed? (ie. the computer would need to be powerful enough to simulate itself and more (ie. the rest of the universe)). If so, this would not only make it less useful, but put significant (increasing) limits on the local age of the descendent universes; assuming (fairly, i think) that the master universe does not have an infinite existence with infinite time between shocks. Also, how would it be possible to store all the information for a universe within itself?
Or perhaps we are talking about imperfect simulations, which would make it much more feasible? but then the infinite exponential chain would not be possible as each child would become more crude. Or perhaps only a (diminishing) proportion of space(-time) is simulated.. or maybe the speed of light decreases as simulation levels get deeper?
In writing this I think I have come to the conclusion that it is impossible (in so far as anything is given our imperfect knowledge), at least a complete universe simulation or an endless chain, but I would love for someone to show otherwise.
[+] [-] jonnathanson|13 years ago|reply
The Douglas Adams-style answer would be that we're some kid's physics homework. Perhaps, in a sufficiently advanced civilization, building a working computer model of an advanced universe is child's play.
An alternative is that the simulators inhabit a very different universe from our own, and that our simulation is something entirely new. It's not a replica of their universe; it's a completely different creation. They could be studying various scenarios, of which ours is just one.
We need to bear in mind that we're approaching this problem from our own, subjective understanding of our universe. It's not a given that the simulators' universe is anything like ours.
[+] [-] ep103|13 years ago|reply
To the first one though, so long as politics and war exist, there would always be reason to attempt to run simulations, regardless of the degree of advancement of a civilization.
By the By, Iain Banks plays around / has a recurring thread of simulations and high powered computers in his culture series, if you enjoy sci fi.
[+] [-] CosmicJohn|13 years ago|reply