Are we living in a simulation? The evidence

Question

I am not questioning whether the simulation topic is outside science. I am asking what evidence there is or could be to resolve whether we are or not.

Living in a simulation has been a topic for philosophy since at least Descartes, with his 'evil demon not less powerful than deceitful'. Zuangzhi's 'Now I do not know whether I was then a man dreaming I was a butterfly, or whether I am now a butterfly, dreaming I am a man' could be argued to be a statement of the same idea. What I am interested in is, is can we get beyond speculation and make headway on this? How does the evidence stand, what tools do we have, and what implications might the different answers have?

Here I quickly summarize some of the main positions:

1. "Are you Living in a Computer Simulation?" [PDF] (2003), Nick Bostrom, makes the case we are in a simulation, on the balance of probabilities

2. "Quantized gravitational responses, the sign problem, and quantum complexity" (2017), Ringel & Kovrizhin, makes the case such a simulation is impossible using classical computers. But that leaves quantum computers.

3. "The Case for Libertarian Compatibilism: A Brief Overview" (2014) gives a more detailed idea of what being in a simulation might mean, as a kind of peer-to-peer reality

4. "Fermi Paradox: a simulation solution" [PDF] demonstrates a serious argument that the simulation hypothesis is the best answer to the Fermi Paradox. Although as recently discussed on here, the existence of this paradox is open to dispute, and relies on a range of assumptions.

Anyone got anything else evidence based? Any models, or discussions of implications?

Answer 1

I would like to argue that the topic (especially the search for proof for it) is rather useless. With a search for evidence, this topic is very similar to the topic of the search for evidence that God exists - which is, naturally, an assumption that brings the term "God" into a field it simply cannot exist in. You can't search for an ontological evidence for something that by definition isn't in the ontological field (or, at least not in the human sense of ontology).

If you want to talk in the logical field, then sure, you can present many arguments for and against the simulation argument, but from your description I see that you know at least some that's enough.

So, my point is, the question is pretty much "worthless" (not really, or else I wouldn't want to answer it, so it is worth replying to at the very least), as a search for evidence in simply not realizing the difference between the fields in which evidence lies and the simulation argument exists.

And for a final note, I think Kurzgesagt (a Youtube channel) presented some excellent points on the hard time it'll be for "aliens" to create a simulation in which we exists (although it does assume these "aliens" live in the same world we live in, with the same physical laws limitations we have, but it's still a nice video to watch - they have amazing animations skills ;).

Answer 2

I propose that we cannot know whether we are living in a simulation.

• One of the ways to detect a simulation supposedly is to detect errors from the inside. But there is no reason whatsoever to believe that our version of the universe has anything to do with the real reality. Every last single piece of our physics etc. could be artificial, hand-picked by our creators (or just by a deep learning machine of theirs, maybe?). We cannot reason about their reality, having only our simulated reality as base. We have no way to see if they made an error in our simulator by perceiving a seeming contradiction in our own universe. There will always be the possibility that our theories are simply wrong or incomplete.
• The complexity of creating such a simulator: We feel that we know a lot about quantum mechanics, black holes and other complicated topics. But compare what we know today (and what kind of technology we have today, both for doing physics, as well as our computing power) with what we knew/had 50 or 100 years ago. Think about what we could have in 50 or 100 years. Absolutely impossible to tell. Now place our simulators, say, 1000 years into the future. There is no hope that we would even recognize what they are doing. We cannot argue in any form or fashion whether building such a simulator would be physically or logistically possible or not (plus, we do not even know the limitations of the "real" universe).

(As an aside, Nick Bostrom does not make the case that we are living in a simulation; instead he - using pure logic, no philosophy, gives 3 possible scenarios; he does not give a probability of which one would be the most likely in our specific case. He says we should look at his three solutions with equal probability, which, to me sounds like he correctly states that we just don't know.)

(Second: that other paper about Fermis Paradoxon contains no hint about us living in a simulation, at all. The authors wrote a simple simulator which makes it possible for them to simulate the long-term life of civilizations - in the scale of 1 million years being one step of the simulation. Hence totally unrelated.)

Answer 3

To focus on the title of the question, there is rather little active research being done around this question, but I'll share what I know.

First is a paper from 2012, Constraints on the Universe as a Numerical Simulation (Beane, Davoudi, Savage). This paper talks about running low level physics simulations that scientists currently perform, and draws comparisons to a theoretical computer simulation of our universe. They theorize about measuring how certain high energy particles are distributed, and provide an upper bound to the size of a grid-like simulation of the universe. However, our most accurate measurements are still orders of magnitude away from being able to determine anything. They close with the following:

Nevertheless, assuming that the universe is finite and therefore the resources of potential simulators are finite, then a volume containing a simulation will be finite and a lattice spacing must be non-zero, and therefore in principle there always remains the possibility for the simulated to discover the simulators.

Next is a recent paper from 2017, On testing the simulation theory (Campbell, Owhadi, Sauvageau, Watkinson). This paper is a bit more philosophical than the previous. There's a bit of discussion on the nature of reality, i.e., "the collapse of the wave function" and to paraphrase "what does it mean to be seen?" The focus is on quantum mechanic effects and present experiment(s) to probe how observers interact with and affect (and effect even) particle interactions. They draw a comparison to video games: often, compute resources are saved by not rendering something that can't be seen. Does something like that happen in the real world (going back to the wave function collapse discussion mentioned earlier)? The paper assumes that observing such an instance of reality suddenly being rendered (or suddenly being rendered in higher detail) would imply that we are in a simulation, but I think the conclusion is not so strongly implied by the premise.

I can't speak to how feasible any of the experiements in the second paper are.

I'm sure there are other relevant scientific papers, but these were all I came across when I was researching the topic (briefly) not too long ago.

Answer 4

Of course it is possible that you are "living" in a simulation right now!

I'd say it is about 50% chance. we call it dreaming and it happens every night.

Well, you might say, that is pure nonsense, for I know I'm not dreaming right now. But do you really?

I dreamed last night that I was in Germany, in a house which looked out on a ruined church; in my dream I supposed at first that the church had been bombed during the recent war, but was subsequently informed that its destruction dated from the wars of religion in the sixteenth century. All this, so long as I remained asleep, had all the convincingness of waking life. I did really have the dream, and did really have an experience intrinsically indistinguishable from that of seeing a ruined church when awake. It follows that the experience which I call “seeing a church” is not conclusive evidence that there is a church, since it may occur when there is no such external object as I suppose in my dream. It may be said that, though when dreaming I may think that I am awake, when I wake up I know that I am awake. But I do not see how we are to have any such certainty; I have frequently dreamt that I woke up; in fact once, after ether, I dreamt it about a hundred times in the course of one dream. We condemn dreams, in fact, because they do not fit into a proper context, but this argument can be made inconclusive, as in Calderon’s play, La Vida es Sueno. I do not believe that I am now dreaming, but I cannot prove that I am not. I am, however, quite certain that I am having certain experiences, whether they be those of a dream or those of waking life. — Bertrand Russell, Human Knowledge: Its Scope and Value

As for the possibility that we are living in a simulation run by some other "people" one world up, I'd say that idea, in my opinion, is just as sensible as last night's dream, and attempting to seriously analyze it, just as silly.

Reality is incomprehensible and mysterious as it is, and the idea of an imaginary one world up, doesn't make an iota of a difference.

Unless of course, it is one of the ideas you are currently playing with, on your way to personally waking up.

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And now that I have claimed above that a serious analysis of the simulation hypothesis is silly, I will add my personal silly analysis of it. It is written from a Buddhist / Advaita / Sufi / Hasidic standpoint:

1. Reality is mysterious, in the sense that it transcends reason and logic and human capacity to comprehend it. It is unspeakable. Unthinkable. The simulation hypothesis on the other hand is a simple thinkable and intelligible idea, just like life after death, or any other silly metaphysical idea about our reality. As such, it does not add or change, or explain anything really. In particular, it does not make anything less real than it already is.

2. Most proponents of the simulation hypothesis conceive of it as a computer simulation or a computational simulation. However, the day you find that which Tibetan Buddhist call self-knowing awareness, or Advaita people call Atman, or Sufis and Hasidic people call Godliness, you will know with certainty that reality cannot possibly be explained as a computation. In fact, the belief that reality may possibly be a computation, is an indication that one is, like almost everybody, still asleep.

Answer 5

No, we're not living in a simulation. See my question https://physics.stackexchange.com/questions/377516/ and especially see John Rennie's answer to it, citing the relevant research.

In addition to that, see Mermin's article http://physicstoday.scitation.org/doi/10.1063/1.880968   A (legal) pdf is downloadable from http://www.physics.smu.edu/scalise/EPR/References/mermin_moon.pdf     In particular, the "gedanken experiment" section, discussed on pages 4-9, involves an EPR apparatus, and demonstrates that the observed results preclude the possibility of instruction sets. That is, the behavior of the separated components of the entangled system cannot be reproduced by (computer-like) instructions.

So, to repeat, no. This entire universe-is-a-simulation stuff is utter nonsense. Utter nonsense. Utter nonsense. Utter nonsense. (I seem to be stuck in a loop)

Answer 6

Statistics

As soon as you establish that creating a simulated universe is possible it becomes more likely that you are within a simulated one.

Imagine someone creates a simulation of a town, an exact replica. If you're a member of this town it is now a 50/50 chance that you're in a simulation vs the 'real' world. Now imagine, to compare, the person loads up a second simulation and runs the two side by side, you only have a 1 in 3 chance of being in the 'real' world.

Run this a few times and you'll find suitably complex simulations will have their own simulations. The number of simulations will vastly outnumber the number of 'real' worlds (if multiple) so your chances of being inside a simulation will always either equal or outweigh those of being in a real world.

Answer 7

We know a lot about simulations, and how they work. Lets look for some of those artifacts in the real world.

Simulations use code, which includes various types of numbers - integers, floats etc. These all have a level of precision that they operate to, and thus a minimum positive value. If the 'real world' was in fact a simulation, we would expect to see physical parameters such as length/distance being quantised, with some minimum value.

Simulations run by advancing one 'frame' at a time, using a loop that updates all objects once, and then paints them to the screen simultaneously. If we were living in a simulation, we would expect time also to be quantised.

As well as minimum values for many parameters, there are usually maximum values in simulations. This is again related to the type of numbers used - after a certain point they will overflow. Sensible programmers put in limits on, say the size of the simulation and maximum velocity.

So, we're currently sitting on 3-4 out of 4 on the 'are we in a simulation' scale. Not looking good.

Answer 8

It is impossible for us to find evidence that we are living in a simulation. All computers that can perform more than a very minimal set of operations are universal computers. A universal computer can simulate any physical system and in particular can simulate any other computer, see:

https://pdfs.semanticscholar.org/e61b/fbc6a38778e1b83088b124a97f2e5009b464.pdf

As a result, there is no way for a person in a simulation to know anything about the hardware he is running on, or even whether he is in a simulation. The laws of physics are incompatible with you knowing that you are in a simulation.

Bostrom's probability arguments are pure handwaving. A probability can only be calculated with an explanation specifying how the probabilities are relevant to the laws of physics

https://www.youtube.com/watch?v=wfzSE4Hoxbc

Bostrom provides no such explanation, so the simulation argument doesn't work.

Answer 9

Nick Bostrum writes in “ARE YOU LIVING IN A COMPUTER SIMULATION?”

Suppose that these simulated people are conscious (as they would be if the simulations were sufficiently fine‐grained and if a certain quite widely accepted position in the philosophy of mind is correct).

John Searle’s Chinese Room Argument (CRA) (“Minds, Brains and Programs”) provided evidence that computers running programs are not adequate to generate human understanding of language. Since we can understand language, we can conclude that we are not living in a computer simulation based on the CRA.

One can pick with confidence between the three alternatives Bostrum offered in the paper’s abstract:

This paper argues that at least one of the following propositions is true: (1) the human species is very likely to go extinct before reaching a “posthuman” stage; (2) any posthuman civilization is extremely unlikely to run a significant number of simulations of their evolutionary history (or variations thereof); (3) we are almost certainly living in a computer simulation.

The posthuman stage is when we have enough knowledge and technology to simulate humans with computers. Given CRA, there is no posthuman stage since the proposed technology is impossible. So the first alternative is true.

Answer 10

I'd argue there are, at least, 3 good identifiers that we're in a digital simulation:

1. That there are globally applicable physical laws i.e. the simulation is algorithmic
2. That there's a limit to the granularity of the simulation and, if you probe below that granularity, the simulation would start to get a bit fuzzy
3. There is an enormous, flaming message half way between here and Jupiter that says "Level 4"

As Meatloaf once said. Two out of three ain't bad.

Answer 11

Suppose that what we call this reality is a simulation. Then by analogy, it is plausible that within this reality we can build machines that contain simulations. Also by analogy one can infer that it is plausible that the reality that simulates our current reality can itself be simulated. This implies that for any particular one of these 'realities', it may be simulated by one, and also simulate one (or more).

Then the question is ... where does it stop? One can infer that you can keep making simulations inside of simulations, and likewise infer a simulator for every one. In either direction it can keep going. So whether it stops above or below or keeps going forever in either direction, we are just one along that chain.

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It's fun to imagine these situations, as in popular culture: The Matrix movies and derivatives, dreams within dreams, counterfactual time travel, a Minecraft world that simulates a Turing Machine that simulates a Game of Life that simulates a 3D-printer that prints off a VR-headset.

Thought can reflect on itself. That is all this is.

Answer 12

I am a bit surprised by the hostility to the concept of this question, given that it is a classic problem restated by nearly every serious philosopher. If your stance is, 'I don't want to think about it', fair enough. No one is making you. This thread is clearly stated as being about evidence for or against. You might have saved everyone time if you didnt want to address that.

I found this great article, that I'd say answers my question as thoroughly as it's going to be. Please consider what it has to say if you have been argueing this is a meaningless question.

"David Chalmers has argued that we should consider the 'simulation hypothesis' not as a skeptical hypothesis that threatens our having knowledge of the external world but as a metaphysical hypothesis regarding what our world is actually made of. " http://philosophycommons.typepad.com/flickers_of_freedom/2014/08/the-case-for-libertarian-compatibilism-a-brief-overview.html

The Peer-To-Peer Reality model framed here seems to me directly comparable to the Yogacara Mind-Only school's stance. The objection around nested or recursive realities can be seen as being directly addressed by Nagarjuna, as described here: https://absoluteirony.wordpress.com/2014/09/17/nagarjuna-nietzsche-rorty-and-their-strange-looping-trick/ Buddhist thought acknowledges reality is confusing, it does not throw hands up and refuse to engage. This avenue of thought looks to be a route towards recognising the sophistication of some Buddhist thinkers.

Answer 13

Science requires proofs. Sometimes scientific theories are built on a number of Axioms or Assumptions.

We cannot prove or disprove that we live in simulation. Though there are many so called "hints" proving that we live in simulation. There are very few "hints" that we don't live in simulation. I welcome everyone to collect more hints proving or disproving the simulation theory. When we get enough hints we can judge the probabilities of one or the other side being more likely.

Some of the hints proving that we live in simulation:

1. Duality of light. It is both particle and wave. Scientific community didn't find any good explanations of that. This duality is very nicely fitting into simulation theory because waves are less computationaly expensive to simulate at the large scale, than simulating each individual particle. Read more on Double slit and Delayed choice experiments.

2. Limitation of the speed of light and connection of speed and time at relativistic speeds. This makes no sense unless looked from the point of view of simulation. "Swapping","Refresh rate" and "Lagging" are well known terms in computer games. When games try to go faster than the computer hardware you get lagging, refresh rate and swapping issues. So limiting speed to certain constant makes perfect sense.

3. Quantum Entanglement makes absolutely no sense unless looked from the prism of simulation hypothesis. Quantum entanglement is instantly connecting two quantums regardless of distance. This can be easily done in computer memory but not in the physical space.

There are many more hints listed in the book I just finished called "Answers In Simulation" by Iurii Vovchenko.

Answer 14

If we say "yes" to this question, its implications would confuse most people and they might say that it is nonsense. But we cannot blame them. Those who follow logical thought cannot admit that idea...there would be a discontinuity in the logical line of thought. Also, there is a possibility of misinterpretation of the words of great men who transcended the dual-state.

You might have heard that Advaita Vedanta gives very great importance to logic/reasoning.

If you say that we are living in a simulation, it implies that the original/real 'we' are living/existing somewhere else.

Also, (if the answer is "yes"), since 'we' are living in a simulation each 'I' would also be living in a simulation. [Each 'I' must be a part of 'we'.] This means, since all 'I's are always living in a simulation, nobody can come out of it (simulation) and realise the Truth or speak it out. I mean, they can't say about that permanent state without realising it. Also, then Truth realisation/liberation would always be a mirage in all aspects. But the truth is not so.

If one's duality is not ended completely he/she can say this to his followers: "'we' are not awaken".

But when his duality is ended completely he would say this to himself: "Actually not we, I didn't know that I was 'sleeping' (means: what I believed as, I was in ignorance)". Or some great men may keep mum about it. This is because they are in a so higher level that ordinary people can't understand.

A person who is not awaken can wake up. Then he has another state. But a person who is living in a simulation has no other choice--just live in simulation and die there. If all of us were living in a simulation we would have no other choice.

So, instead of confusing by 'splitting' the term jagat into 'we', 'living' etc they (those who could transcend duality ... when they speak about the Absolute Truth) denied all the plurality and said, "Brahma satyam jagan-mithya". [Brahman is real, the universe is mithya (it cannot be categorized as real or unreal)].

Since everybody's abilities are not alike, their (those great men's) advice is for self-realisation, for serving fellow beings etc. They didn't say that we are living in a simulation. By such statements (approval) people may become inactive/disappointed/gloomy because if it is true there would be no scope for realising the Truth). If such a society is created by this confusing statement, I would say that this is the ugliest face of philosophy. But we can say, we (those who didn't realise the Truth) are not awaken in the true sense. Since there is a higher level of awaken state, there is no mistake in it.

You should compare the meanings of mithya and simulation. You can see the variance if you could replace the phrase--'in a simulation' by 'mithya'.

Please google for explanations of jagan-mithya:

https://www.speakingtree.in/blog/brahman-satyam-jagat-mithya

Answer 15

Maybe I am very naive, but I know I am not living in a simulation. My evidence is my free will!
I interact with other people and see that they also have free will. Therefore, I conclude that we are not living in a simulation.
I am aware of the controversy relating to free will, but from my point of view, there is no controversy.

Answer 16

The idea of the illusory nature of reality has been around since the beginning of humanity. Perhaps the Vedas 1100-1700 BC were the first ones who deeply pondered about it. The simulation hypothesis is just a new technological possibility to create fake realities or distort them which is no different than holding people captive in a dark cave (Plato) or blinding them(Bible).

Ordinary dreams and astral projections produced by sleep, deep meditations or psychedelics remind us of the illusory nature or reality and how persistence and consistency are its defining characteristics.

"Reality is merely an illusion, albeit a very persistent one" Albert Einstein

What evidence is there? It's all about probability. If something may happen then it will happen or it has already happened.

"There’s a ‘One in Billions’ Chance Reality Is Not a Simulation" Elon Musk.

What if we awoke from this reality into another reality? Would this new reality be "real" or just another illusion? How can we know? What if it was a simulation within a simulation? Could we have endless simulations embedded into one another?

I guess the problem with the whole simulation hypothesis thing is within the human psychology and mind. Why do we want reality to be "real"? Perhaps we are afraid of digging any deeper because we are emotionally dependent on our past, ego, physical bodies, skills, culture, social status etc. and many other impermanent things and that illusory/impermanent nature of reality confuses us and makes our ego feel threatened but it's only reminding us of what we are not as said in Buddhism.

"I knew that most people never see this reality because they attach to the material aspect of the world. Illusions of self and other fill their vision. I also realized there are those with little dust limiting their vision." Buddha

I guess the problem with the simulation hypothesis is the same problem with religion and a creator god. Sometimes when there is no proof in favour or against it's hard just to be agnostic.

Answer 17

Categorically this question only has one correct answer:
(a) If we are living in a perfect simulation such that there is no discernible difference between the simulation and reality then by definition there is nothing telling the difference.

(b) If there is a discernible difference then discerning this difference tells this difference. Instead of hypothesizing every possible way that this difference could be discerned let's cut to the chase. The difference that proves that we are living in a simulation is that physically manifest reality can be changed by thoughts kept silently in the mind.