For a game that simulates an entire universe on the macro scale, the Space Engine forum seems to be strangely lacking in a topic discussing the simulation hypothesis. For the sake of completeness, I will create it here. I am aware that there is some contention surrounding the subject, and that it is unfalsifiable scientifically. Thus it is in the Off-topic Discussions forum.

For those of you unfamiliar with the hypothesis proposed by Swedish philosopher Nick Bostrom, there is a ton of hyped-up content online that you can research. Here are the actual papers published by Bostrom on his website that are a good start for investigation:

https://www.simulation-argument.com/

There are a few videos done on the subject by Isaac Arthur, among others, on YouTube that are also quite good. If you follow him and his group of futurists, you should be in good company to discuss this topic. 

This is meta-physics, but: Why aliens? You could just as well be in a simulation created by humans (or mice or whatever), and the simulation was created just for you.  Your brain is the centre of the simulation. Everything you see, everybody you meet, was created for you to experience in the simulation.

There must be many ways to dismiss simulation arguments by reductio ad absurdum.

This is meta-physics, but: Why aliens? You could just as well be in a simulation created by humans (or mice or whatever), and the simulation was created just for you.  Your brain is the centre of the simulation. Everything you see, everybody you meet, was created for you to experience in the simulation.

There must be many ways to dismiss simulation arguments by reductio ad absurdum.

The simulation needs a 'prime mover' that made the simulation. Basically 'god' from those inside the simulations point of view since its objectively impossible to prove from within the system, because that would be equivalent to us proving that something exists beyond our actual universe (assuming of course the simulation even simulates all of it, which it probably wouldn't). I know we have multiverse and string theory pertaining to some of that stuff, be you get the idea.

But yeah, its pretty metaphysical. Fun to talk about, but it borders on sensitive personal beliefs. I try to avoid that if at all possible. Are there any original ideas you came across to debunk/prove the simulation?

If we were living in a computational or computer simulation I could easily crash it, obliterating everything & killing all of us, with a few predictive algorithms that would require exponential powers of mathematical computation, "memory" or time.

I'm not so sure about that.  No simulation you could ever do on a computer would be even remotely comparable to the computational power needed to model the interactions of every particle with every other particle in the universe.  And even if you could, the simulation that you are running is built off of particles interacting, which the "universe simulation" would already be doing anyway.  So I think the higher level simulation simulates your simulation crashing and cares not one whit.

There might be arguments for why living in a simulation is more or less likely, inevitable or absurd... but I don't think it's practically falsifiable.  Even if it is true, it's still the same universe, with the same behaviors we've always known and discovered by doing science.  Being a simulation doesn't change anything.  And to me that's why it's uninteresting.

If living in a simulated universe, we know nothing of the physics of the real world, and simulating our reality in that real universe could be quite plausible.  But without hints of the "real" world leaking into our world, all simulated world arguments are pointless.

That is the crux of the matter - finding those hints. Could some of the phenomena we see in quantum mechanics be those hints?

Yeah that sounds pretty rhetorical...

Perhaps the purpose of the simulation we live in is to explore whether an intelligent race manages to conquer the (simulated) space, though we can not be faster than the speed of light!
In the higher-level universe, this limit may not exist!
(Maybe that's why we do not find any traces of aliens. There are none in our simulation, they were not considered necessary. (Fermi paradox.))

Perhaps the purpose of the simulation we live in is to explore whether an intelligent race manages to conquer the (simulated) space, though we can not be faster than the speed of light!
In the higher-level universe, this limit may not exist!
(Maybe that's why we do not find any traces of aliens. There are none in our simulation, they were not considered necessary. (Fermi paradox.))

Probably the oldest given example as to why a simulation is needed JackDole, as a derivative of the so-called 'ancestor simulation' wherein the programmers are merely experimenting with an intelligent code (us) and getting them to interact with whatever they throw at us (some sort of physics hurdle). Its solution for the Fermi Paradox is almost too convenient.

Watsisname wrote:
There might be arguments for why living in a simulation is more or less likely, inevitable or absurd... but I don't think it's practically falsifiable.  Even if it is true, it's still the same universe, with the same behaviors we've always known and discovered by doing science.  Being a simulation doesn't change anything.  And to me that's why it's uninteresting.

True. But then again, by the same logic, studying the properties of distant stars doesn't really change anything here on Earth in the 'here and now' from a subjective standpoint, all an astronomer is doing is applying Periodic chemistry and physics to a object that for all intents and purposes, may not exist anymore (considering light lag). For somebody who is not interested in astronomy, they would refuse to hear or believe the astronomers reasons for studying that star, no matter how hard the astronomer tried to tell them that it is important. They would say that the astronomers methods are 'unfalsifiable'  from their viewpoint, simply because they do not understand them (having never studied physics, chemistry or astronomy in general).

That would be the problem here. We assume we do not understand the methods of, say, 'The Programmers' (Man, that sounds so theological  ), and to say that its 'uninteresting', is to play a modified version of "God moves in mysterious ways" wherein you should not question motives, because they do not directly effect you or change your subjective world since they are so 'lofty'.

Even if the star in the aforementioned example did explode and go supernova and killed everybody on Earth, including the uninterested fellow, would that make the studies of the astronomer valid? No-one is around to tell him of course, so does it objectively exist?

We may have the unique position here to vindicate that - and actually know what the simulation is (if it even exists) because at some point in the perhaps not-so-distant future, we could make an actual universe simulation of our own (we already sort of make them now, just not on the epic scale assumed to make them The Simulation). We know what would be needed processor-wise (roughly) and the power-requirements for that. Would that change the argument? Maybe not. Our science is based on observing the physics (or 'code' if you want to believe in simulation theory) of the universe we live in via the scientific method. Hence our science is not valid outside of it, in the so-called 'true universe' of The Programmers. The only way around this is too assume that our universe is based on the same laws of the original universe. We could learn this by looking for the 'leaks' of the true universe mentioned by midtskogen. Unfortunately, assumptions do not make for good science, but are great for metaphysics.

I realize this is philosophical, and what I wrote is just philosophical debate-bait, but that is why this I created this thread .   

It's becomes a game you play inside your own mind. Where reality can be anything that you can imagine. And that's actually where we stand today in the academic world of physics and cosmology. In what's been called a "Swampland" of competing ideas, far from solid truth. The only problem is no one knows the difference between what is swamp and what is dry land.

You now have theoretical physicist debating and conjecturing non-solutions to String Theory (the reasoning is probably closely tied to funding). By formulating all possible wrong theories, one might stumble across the "Correct Theory". Of course we are just conjecturing there is a theory, within certain limits, that will fit the model that we've created in our own minds, but which is truly separate from reality.

String theory, the multi-verse, runaway inflation and the Copenhagen Interpretation have made a mockery of Physics. They are great ideas, but just like all great ideas on acid, they really don't make sense when held next to each other.

I don't see the Holographic Principle or Simulation Hypothesis as any different than the swampland of non-solutions to string theory.


Theorist in a Swampland

But to play Devil's Advocate...
Proton entanglement, that spooky action-at-a-distance, which bothered Schrodinger and Einstein so much might be weirder than anyone first thought.

It's been shown there is the existence of quantum correlations between temporally non-local photons. That is, entanglement can occur across two quantum systems that never coexisted at the same time.

That's like saying that the polarity of starlight in the far-distant past, say, greater than twice Earth's lifetime nevertheless influenced the polarity of starlight falling through your amateur telescope this winter. Even more bizarrely: maybe it implies that the measurements carried out by your eye upon starlight falling through your telescope this winter somehow dictated the polarity of photons more than 9 billion years old.


Aeon Magazine article on Temporal Entanglement

That's how weird our own universe is without the need for something else outside of it.

 

They would say that the astronomers methods are 'unfalsifiable'  from their viewpoint, simply because they do not understand them (having never studied physics, chemistry or astronomy in general).

I have to agree with Watsisname here. I think the fact that something is important or not is not the issue here (to evaluate if it is uninteresting). Nor the fact that something is just unknown (that looks a lot interesting to me) or if it's to far away from us to reach and experiment with right now (as I think you were implying in the astronomy example). Is the fact that something is unknown plus the fact that there is no possible experiment to grasp any detail of it because the nature of the hypothesis constrains any debate to the "outside of physics" realm, where everything is possible. If your hypothesis requires the imposibility of you making a single observation that could make that claim either more robust or less probable then it is unknowable by law (unfalsifiable and metaphysical indeed).

I think unfalsifiability has for experimental science the same role as the principle of explosion has for mathematics. I like to recall the Bertrand Russell's ilustration of the idea that "a false proposition implies any proposition". Let's say that 2=1. This is a false and contradictory idea since that means any number is any other number; for example adding both sides by -1 leave us with 1=0 and multiplying that by 39 (for example) gives you 39=0, adding +1 leaves you with 1=40. But maybe this breach in logic just breaks numbers as separate identities but leaves the rest untouched. Wrong. When you come up with a contradiction you can state anything! For example, let's prove that Bertrand Russell is the pope; "If we have 2=1. The set containing just Bertrand Russell and the Pope has 2 members. But 2=1, so it has only 1 member; but who of them is that member of the set? since that would make a second contradiction with the definition of our set, the only conclusion is that Bertrand Russell is the Pope".

The axioms of logic can be changed to yield "other mathematics" but it turns out that there are few sets of alternative axioms that are self-consistent and yield a specific set of mathematical statements. In general any change would produce "all is valid mathematics". If you for example break the identity axiom (that states that for any-thing that "thing" has to be the same as itself) you could say that a triangle has 3 vertices but at the same time it has 5 vertices, or none. So there is not a specific mathematical statement. Anything is valid now. That is boring and uninteresting. Why? because of another thing called information entropy. When everything is equally possible and valid (even contradicting ideas) we have reached maximum information entropy; a soup of indistinguishable ideas from where any reasonable meaning is impossible to extract (as in maximum thermodynamic entropy any usefull mechanical work can't be extracted). The "everything is possible" realm lacks any interest because there is no physical reason any neuron should spark inside your brain any conceivable idea when any usefull infromation can't be extracted from outside your skull. You only can do that because 1) you are not an objective machine and 2) because you are lowering information entropy in some way, assuming there are things that are less likely than others. For example, the idea that your grandmother is the creature runing the simulation might seem less likely than an "alien multiverse being", or the idea of the simulation been self created and that it popped up spontaneusly and without design also seems less probable than others. But that is wrong; all statements are equally probable when you can't build any experiment (by definition) that could discern between one and other proposition. You might think there is space for meaningfull reasoning but there is not, because we are drowning in the information soup, and the only reason you might think like that is because the folklore of your culture, your personal beliefs or any other idealistic cause have inspired you to think that your grandmother been the programmer of the universe looks silly (when it is not) and therefore you feel that maybe there is some way to assing different plausability to different statements inside your hypothesis from where to decrease information entropy and extract meaning, but the truth is the way the simulation hypothesis is framed there is no way to generate that plausibility differential (because there is not a single experiment that can be performed to falsify one or the other).

You could prove that the "real universe", where the simulating machine is placed should be larger than ours if they had the same physical laws as the implemented in the simulation itself (it is impossible to perform a simulation where all the quantum interactions of the universe are taking place using as many computational resurces as our universe has). But who said that "their universe" has similar physical laws? Is there any conceivable experiment to show that? What if their universe has different laws? What if they have the same laws but their universe is larger? What if their universe is still small but they are running the simulation with a different timescale and each of our second is been calculated each trillion years of the "real" universe. You can always come with an idea that impedes you to falsify any proposition about your hypothesis. All is valid.

I've heard that the similarities between our physical laws and a computer simulation are suggestive; the fact that some magnitudes are quantized (even space-time could turn out to be discrete) sparks associations with the digital world, with concepts like pixels (quantized screen space) or time-steps or iterations (quantized time) etc... The fact that the simulation is not infinite and there are regions that are unaccesible like the end of the map in a videogames, is similar to the fact that we can't explore certain regions of space or extract any information from them. There are walls and event horizons all across the universe (are black holes physical limitations of the simulation itself? are they bugs in the code?). All of that speculation is "fun" in some way but meaningless if there is no experiment that can talk to us about it. It is just an expansion of our cultural suggestives ideas, tthe association between unconnected concepts and reminders of our ability to search for similar patterns to what we experience in our daily lives. Looks to me too antropocentric.

There is another reason why this is "boring". Astronomy has great unknowns but none of those explicitly tells us that we are under the rule of observations and experiments that are impossible to construct because of the way it is framed. We can't touch stars but only for now! it definetely is not impossible. We can still see them with electromagnetic radiation and we have physical laws that have been experimentaly shown to be valid in many other contexts outside of astronomy that allow us to infer more in the unknowns of astronomy. With the simulation hypothesis this is just not true. If you can't see, if you can't feel with any organ or any instrument (sensory organs might bee artificial in a broad sense), if there is no way to interact with the "outside world" then Is it important if it actually exist or not? There is no way to discern between this "ouside world" and nothingness since both have the same consequences for us, they are exactly equal from an epistemic standpoint, and you know if there is something that characterizes a debate about nothingness is that it is very very uninteresting.

The thing I find interesting is what "real" means for any of you (interesting because that really has meaning and tells something about what inspires modern humans to construct such abstract ideas). For me, "real" is what can be experienced or documented by observations. Real world is where all the interactions occur. I don't really care if that world is a simulation because that doesn't diminish its physical/materialistic reality and the fact that interactions are occurring between the elements of the simulation. If this is a simulation, for me this wouldn't mean in any way that all I experienced was unreal or fake. It would be as real as before, but now I would know that there is also another "real" to which expand and generalize my experience of the cosmos. I think we all have the tendency to fall into a solipsism when we talk about this.

One final note; the fact that, in this thread, we all agree that the simulation hypothesis is part of metaphysics is awesome. You are truly concious and wise people (at least out of the common I would say)

Our science is based on observing the physics (or 'code' if you want to believe in simulation theory) of the universe we live in via the scientific method. Hence our science is not valid outside of it, in the so-called 'true universe' of The Programmers. The only way around this is too assume that our universe is based on the same laws of the original universe. We could learn this by looking for the 'leaks' of the true universe mentioned by midtskogen. Unfortunately, assumptions do not make for good science, but are great for metaphysics.

Yes, exactly.  And as FFT explained (fantastic post by the way, FastFourierTransform).

I say it is uninteresting to me not because here is a whole bunch of phenomena I could try to understand but choose not to, but rather because I have no tools to try to understand it.  Everything within the universe I can, in principle, observe, quantify, build models for, and test those models.  Everything "outside" the universe, I cannot.  I cannot make measurements that will tell me whether quantum mechanics is how the simulation handles particles, or whether quantum mechanics is simply "nature being strange."  What I can do is figure out how quantum mechanics works and use it to predict the behavior of particles.

Making assumptions about how the "true universe" leaks into our simulated one is not in itself a problem.  The problem is if we cannot test those assumptions.  In what way would those leaks into our universe be distinguishable from the universe simply being... the universe?

Making assumptions about how the "true universe" leaks into our simulated one is not in itself a problem.

This seems to me as a general problem even in current science.  We can't know whether what we perceive as reality is just an emergent feature from a reality which is fundamentally hidden to us.   We're stuck with what we can observe, whether it's a simulation or an illusion.

All of that speculation is "fun" in some way but meaningless if there is no experiment that can talk to us about it. It is just an expansion of our cultural suggestives ideas, tthe association between unconnected concepts and reminders of our ability to search for similar patterns to what we experience in our daily lives. Looks to me too antropocentric.

There is another reason why this is "boring". Astronomy has great unknowns but none of those explicitly tells us that we are under the rule of observations and experiments that are impossible to construct because of the way it is framed. We can't touch stars but only for now! it definetely is not impossible. We can still see them with electromagnetic radiation and we have physical laws that have been experimentaly shown to be valid in many other contexts outside of astronomy that allow us to infer more in the unknowns of astronomy. With the simulation hypothesis this is just not true. If you can't see, if you can't feel with any organ or any instrument (sensory organs might bee artificial in a broad sense), if there is no way to interact with the "outside world" then Is it important if it actually exist or not? There is no way to discern between this "ouside world" and nothingness since both have the same consequences for us, they are exactly equal from an epistemic standpoint, and you know if there is something that characterizes a debate about nothingness is that it is very very uninteresting.

Nailed it. Anthropocentric is the word I think we are all looking for. This brings to mind that thing Donald Rumsfeld, then US Secretary of State for Defence, said at a Defence Department briefing: ‘There are known knowns. There are things we know that we know. There are known unknowns. That is to say, there are things that we now know we don't know. But there are also unknown unknowns. There are things we do not know we don't know.’

It goes without saying that most of science falls under the first two. It is the nature of unfalsifible info-entropy ideas, along with completely abstract ones such as those we find in the more wilds corners of quantum theory to characterize as best we can the unknown unknowns. They are outside our subjective realm and thus outside the universe for us.

I find the simulation hypothesis entirely too seductive, though I will entertain it endlessly because it is quite fascinating. A bit too fascinating, and therefore dangerous because to encourages lazy thinking and as we have explored here, bad science. It could very well be an explanation for almost anything we see in the universe (or at least partially responsible for it), but then we fall into the very slippery slope that is `God of the Gaps`. I think we on this forum know well that this way of thinking is very persuasive in our modern world. The best known example is of course embodied in the worlds religions, but it is very prevalent in UFOlogy and Erik Von Daniken`s `ancient aliens` (ignoring for the moment some of the other well-known issues with those `fields`). Add that with a healthy dose of hype from the news and internet and we have this mess of ideas and non-factual paradoxical speculations. The public (and even some scientists) seem to have lost sight of the original intent of Nick Bostrom`s hypothesis: it was a thought experiment for the FUTURE. The title was a non-sequitur and rhetorical. Its sort of what philosophers do; thought-experiments. It is basically a sound theory because there will be very little stopping our descendants from making simulations of things in our universe that from the inside at least would be unmistakable from reality, that is if our world is going the way most futurists think they will. Futurists can be a fickle lot anyway.

Also, for those of you who may have read the papers by Bostrom, remember he stated that three things are possible in regards to this: 1) either we are in a simulation because it is a too inevitable technological advancement to avoid and statistically you are more likely to exist as a thinking being in a simulation then the true universe, 2) that we are not because future humanities think it is unethical (or whoever is making this simulation, could be aliens) or 3) we are not because it is impossible to make. I would add another: if they do exist, simulations could be for only limited, but HIGHLY detailed environments that observers from the outside or those uploaded and or generated from the inside can exist in. The latter is the one I lean towards but am in no way enamored of.

DoctorofSpace directed my attention to this video by PBS SpaceTime on our Science & Astronomy videos thread. I thought it might be appropriate for here as well:


[youtube]0GLgZvTCbaA[/youtube]