that claimed something along the lines of: that every sufficiently advanced civilisation will eventually construct a universe simulation. — Kaarlo Tuomi

I should think that an advanced civilization would have long since recognized there is at least one thing that cannot be simulated, the universe. I, myself, happen to be a member of that civilization. If you're not, can you describe just how you might go about simulating the universe?

1. what does having made a simulated universe say about the civilisation that made it? — Kaarlo Tuomi

Depends on how sophisticated the civilization becomes I guess and what they're actually using simulations for.

'O God, I could be bound in a nutshell, and count myself a king of infinite space – were it that I had sufficient control over the simulation.'

Simulations bridge physical distances. You can do pretty much anything without going anywhere, so the energy savings would be substantial.

The actual cosmic distance between planets likely makes traveling to other solar systems untenable, so naturally one would expand a sense of inner space with simulations.

2. given that the simulation is, or should be, undetectable by those inside it, how, precisely, does its existence communicate anything to anyone else? — Kaarlo Tuomi

The ones inside it are presumably the ones who made it.

, I think you might be referring to Nick Bostrom's argument.

Simulation hypothesis (Wikipedia)
The Simulation Argument (Bostrom)

There are various details of these arguments, including how likely it might be for sufficiently advanced beings to put together simulations.

Nils Loc said: The ones inside it are presumably the ones who made it.

that isn't an assumption I would have made.

the assumption has always been that a civilisation, A, constructs a simulated universe containing simulated civilisation B, so that to B, A bears all the hallmarks of being god.

I can't personally imagine how A would construct a simulation of their own universe that includes themselves, but that's probably a limitation of my imagination rather than of your description.

Kaarlo Tuomi.

Simulations bridge physical distances. You can do pretty much anything without going anywhere, so the energy savings would be substantial.

The actual cosmic distance between planets likely makes traveling to other solar systems untenable, so naturally one would expand a sense of inner space with simulations. — Nils Loc

That's the use that I can see for universe simulations generally. I predict that the far future isn't going to be human beings bodily traveling the stars, but of an increasingly sophisticated and defensible civilization here at Sol (Dyson sphere with star-lifted fuel supply and a stellar engine), with Earth, its biosphere, and human civilization preserved amidst it, while a swarm of AI-directed robots explore (and similarly transform) the universe, reporting detailed information about it back to Sol, where we can then "follow" after them virtually.

But the usual hypothesis that leads to this train of thought is that an advanced civilization would build a simulation for scientific purposes. They'd want to know what a universe like such-and-such, including people like so-and-so, would be like, so they make a model of one and see what happens in it. In a sufficiently advanced model, the modeled people in it might actually be fully conscious beings perceiving the model as their universe.

There's little reason I can see why one would want their simulations to start to contain simulation ad nauseum. You can't just go on nesting forever: every bit of memory and processing power used to simulate a simulation in a simulation is more memory and processing power the top simulation needs, so on a fixed computational budget the deeper universes have to get smaller and simpler, and the computational budget of one where they don't do they balloons exponentially. so the usual "we're probably in a simulation because most universes are simulations" argument fails to persuade me.

Pfhorrest said: ...an advanced civilization would build a simulation for scientific purposes. They'd want to know what a universe like such-and-such, including people like so-and-so, would be like, so they make a model of one and see what happens in it. In a sufficiently advanced model, the modeled people in it might actually be fully conscious beings perceiving the model as their universe.

thank you. this answers my question. and it also answers what was going to be a follow-up question.

I could never understand why it would matter to the sumulators that the sims don't learn that they are sims. by analogy, why would it matter to me that my pet goldfish has learned she is a fish in a tank?

in your scenario, the motivation is the fidelity of the experiment.

thank you.

Kaarlo Tuomi

Glad I could help. :-)

I can't personally imagine how A would construct a simulation of their own universe that includes themselves, but that's probably a limitation of my imagination rather than of your description. — Kaarlo Tuomi

You can't imagine aliens in VR but you can imagine alien physicists doing high-fidelity ancestor simulations which produce self-conscious beings? Hmmmm. Fishy.

Am I being tested by the simulation?

You can't imagine aliens in VR — Nils Loc

I can't imagine aliens inside the VR they had created. by analogy, I don't expect to meet Bill Gates inside the Microsoft Flight Simulator. there might be a virtual Bill Gates, or a hologram of Bill Gates, but not the actual Bill Gates.

Kaarlo Tuomi

I can't imagine aliens inside the VR they had created. by analogy, I don't expect to meet Bill Gates inside the Microsoft Flight Simulator. there might be a virtual Bill Gates, or a hologram of Bill Gates, but not the actual Bill Gates. — Kaarlo Tuomi

Eh, just speak directly. It isn't that you can't imagine it as much as you don't wish to consider such a scenario in this discussion.

If you are meeting Bill Gates via Skype, are you really meeting Bill Gates?

It isn't that you can't imagine it as much as you don't wish to consider such a scenario in this discussion. — Nils Loc

no, that isn't it at all. I genuinely cannot imagine how anyone can physically construct the universe in which they live.

this is largely because I think of a person as inhabiting a universe. then anything that person constructs must be inside the universe they inhabit. I cannot envisage how they would then get inside the universe they just constructed.

but, like I said, that is probably more to do with the limits of my imagination than anything else.

If you are meeting Bill Gates via Skype, are you really meeting Bill Gates? — Nils Loc

this just seems to be making my point for me. the real Bill Gates cannot get inside Skype, all I can see there is an image of him, a projection of him, but not the actual Bill Gates.


Kaarlo Tuomi

I think of a person as inhabiting a universe. then anything that person constructs must be inside the universe they inhabit. I cannot envisage how they would then get inside the universe they just constructed. — Kaarlo Tuomi

Any constructed universe (just a name for a necessarily simpler simulation) is nested in your universe. There is no way a simulation could duplicate the complexity of the actual universe.

If it did, you'd end up converting the universe itself in a total reconstruction toward a new past or a future.

1. what does having made a simulated universe say about the civilisation that made it? — Kaarlo Tuomi

It reflects progress and expectation. To simulate a universe in which the civilization is reflected implies uncertainty on the part of the creators. Man is looking for ways to survive, so then the simulation will reflect overlooked damaging properties. If these are identified (due to the revealing nature of complexity), updates become eventually applied, ending in absolute resolution.

What you have then is "stripped" progress during intermediate stages, and because inhabitants of the created world lag and lack details in construction policies, so do we in our knowledge. This conjures not only restriction, but also the ability to rewind. So then, when a quantum leap breaks the symmetry of progress, it would be like discovering prime numbers in nature. Usually this implodes the symmetrical decimation into natural standards which is of course impossible as we do not understand the nature of time fully.

Its easy to model singularity, but nobody in the simulation has ever actually seen it, let alone construct it in the beginning with a beginning.

It reflects progress and expectation. To simulate a universe in which the civilization is reflected implies uncertainty on the part of the creators. Man is looking for ways to survive, so then the simulation will reflect overlooked damaging properties. — Francesco

thank you for engaging on this.

I like your idea that the simulation has a dual nature, reflecting both progress and expectation, which are hopeful properties, but also the uncertainty about their own future. I think the philosophical question whether humans are inherently good or bad is unanswerable because we are both, and the duality in your reply reflects this. I agree with you that the creators of the simulation can be both proud of their achievement and yet fearful of the consequences of previous mistakes.

however, these things, these properties and qualities, are being communicated. we use expressions like "the simulation says," but it is not clear who is supposed to be the recipient of this message. who are they saying these things to? if all they are doing is communicating it to themselves then why do they need to go to the huge cost and trouble of constructing something as massively complicated as a simulated universe. surely, a front page ad in the New York Times would do the same thing.

okay, the ad in the New York Times would not permit them to explore alternatives, to literally see the consequences of their choices and to experiment with the starting conditions of universes to see which initial conditions lead to life and which do not. they could experiment with different initial processes by which life is formed to see which ones lead most efficiently to intelligent life, they could practice tweaking evolution to get a more perfect them, they could achieve so much. which suggests that whatever they tell their fellow citizens, the real purpose of the simulation is to conduct these experiments. it is not a vastly expensive tweet on social media, it is a laboratory.

what can they then do with the knowledge they have acquired?

they cannot wind back the clock on their own civilisation to start again from the beginning, they cannot recreate themselves anew in their own universe so that they can experience first hand this new and hopeful future. they cannot, as far as I can see, use this knowledge in any way that benefits them at all. this knowledge can only be used to benefit some other civilisation that exists in a simulation created by them.

it is therefore the acquisition of knowledge for its own sake. and therefore, what the creation of a simulated universe says about the civilisation that created it is, that they are curious.


Kaarlo Tuomi

There is no way a simulation could duplicate the complexity of the actual universe. — Nils Loc

I don't play computer games but I have been reading about advances in the way these games are programmed so that the world within the game has become richer and more textured and nuanced with much greater detail than was previously thought possible.

one of the techniques they use is that the world is created only in the immediate vicinity of the character. if the same idea were applied to a simulated universe then it would only be necessary to simulate those parts of it in the immediate vicinity of, or accessible to, the subject. when I am in my living room there is no need to simulate the entire vast expanse of the Mongolian steppe and the waves rolling across the Pacific ocean and the dust clouds circling the Orion nebula, because these things are outside of my experience and from the context of my consciousness they do not "exist". if I go to my window and look through my telescope it would be necessary to simulate not the vast immensity of the cosmos but only that tiny portion of it visible through my telescope. in this way I think it entirely possible that a simulated universe could recreate the illusion of being as vast and complex as an existent universe, without actually being so.

a simulation need not be an exact copy, but merely smoke and mirrors.

Kaarlo Tuomi

I should think that an advanced civilization would have long since recognized there is at least one thing that cannot be simulated, the universe. I, myself, happen to be a member of that civilization. If you're not, can you describe just how you might go about simulating the universe? — tim wood

If we can simulate two particles bumping together, a nuclear reaction, and objects dancing through space, what abstraction separates the simulation of a universe? Size?

Supposing we have a universe-sized chunk of universe to work with, can that not be used to house the computer that simulates the (a?) universe?

If a 100 story building collapse can be simulated by a computer that occupies 1 floor, why can't a computer 1/100th the size of the universe simulate the universe?

Even so, how much universe would need to be simulated before the universe could be considered a universe? How much experience of this universe led you to consider this universe to be a universe?

no, that isn't it at all. I genuinely cannot imagine how anyone can physically construct the universe in which they live.

this is largely because I think of a person as inhabiting a universe. then anything that person constructs must be inside the universe they inhabit. I cannot envisage how they would then get inside the universe they just constructed.

but, like I said, that is probably more to do with the limits of my imagination than anything else.

Perhaps if you learn how to unleash your imagination (free it from the Western mindset) you might be able to. Before I describe the way I see it, I will point out that Hindu mythology has seen it this way for millennia and this is why the various deities you will find in Hinduism and Bhuddism have fantastical properties. Because this way of viewing reality is foundational to their religion and mysticism.

If you allow for the possibility of beings being able to traverse dimensions then you have a means to solve the conundrum of how the creator of a universe can inhabit that universe. A being creates a three dimensional universe while inhabiting a fourth, or fifth dimensional universe. Then steps down to become present in the three dimensional universe via some appropriate vehicle (a human body).
(The reality in the mythology is more complex than this, but that is essentially what is envisaged)

Also it helps to free your imagination from the conditioning about physical material and rigid time and space. So for example I imagine my self, my being, as a constellation of beings from many different dimensions and scales, all cooperating as one, from entities the size of an atom to entities the size of a galaxy for example, each playing a role which is their nature, within me, outside the rigid three dimensional universe I experience. So physical material, time, scale as I experience them are a construct/simulation produced and maintained by the activity of that constellation of beings.

So for example, every utterance from my mouth reverberates across the universe for all eternity and is imbued with the vibrations of all the other utterances uttered by all the other beings. Not just physically, but also subjectively.

A being creates a three dimensional universe while inhabiting a fourth, or fifth dimensional universe. Then steps down to become present in the three dimensional universe via some appropriate vehicle (a human body).

thank you very much for engaging.

I have to admit that I found your description quite compelling, and surprisingly understandable, for which I thank you. but I could not at first understand why a being who inhabits a four or 5-dimensional universe would want to limit themselves to the boring old 3-dimensional space we inhabit. but then I thought of hermits and folk who live off-grid for various reasons. these people consciously restrict their interaction with the world in various ways to arrive at their particular version of peace and harmony. I'm not suggesting that anyone who lives alone in the woods is from a 5-dimensional universe, but the most compelling myths and legends often contain some element of the truth. there is a reason, for example, why the Amazonian indians thought god had red hair.


Kaarlo Tuomi

A fifth dimensional being might have numerous reasons to create, or go to a 3 dimensional universe. Like a fertile ground for seeding fledgling beings for example, which might occasionally require assistance, weeding.

why the Amazonian indians thought god had red hair.

Yes, I have come across this mythology.

A fifth dimensional being might have numerous reasons to create, or go to a 3 dimensional universe. Like a fertile ground for seeding fledgling beings for example, which might occasionally require assistance, weeding. — Punshhh

In fact I am one of them 5th dimensional creatures. Unshackle your eastern imagination... Behold!

what can they then do with the knowledge they have acquired?

they cannot wind back the clock on their own civilisation to start again from the beginning, they cannot recreate themselves anew in their own universe so that they can experience first hand this new and hopeful future. they cannot, as far as I can see, use this knowledge in any way that benefits them at all. this knowledge can only be used to benefit some other civilisation that exists in a simulation created by them. — Kaarlo Tuomi

Your assumptions are so arbitrary but this partly due to the speculative nature of the premise. Just extend the uses we have of simulations now to understand how such a civilization might use them.

Perhaps they want to avoid existential threats and so run through billions of scenarios to try to understand how to avoid otherwise unforeseeable problems.

Perhaps they want to see how likely it is for intelligent life to emerge with a different set of elements.

Maybe they want to visit another simulated time in VR and meet their dead relatives.

The list of speculative uses seems like it would be very difficult to exhaust.

I'm all ears, teach me.

What if it is a necessary simulation? Simulation might be a part of nature. Perhaps folk who think on it should look to ways it might be happening in nature, rather than via computation.

1. what does having made a simulated universe say about the civilisation that made it?
2. given that the simulation is, or should be, undetectable by those inside it, how, precisely, does its existence communicate anything to anyone else? — Kaarlo Tuomi

That it knows how to turn minerals into circuitry, at least. Most civilizations are diverse, just because someone from somewhere did a thing doesn't necessarily represent the society.

What do you mean by "those"? Is my World of Warcraft character it's own person now for some reason? Getting into AI/trans-humanism otherwise. Very controversial. Is it like a memory transfer thing where I exist outside of it and a character with (assuming it could be possible- my exact memories and persona per se) is in this simulation and so can develop itself further and become someone else? How would it be tied to me, here?

the thing I've really enjoyed about the comments in this thread is how many folk have considered the idea of a simulated universe in ways I would not have thought of. this has caused me to step back a bit and reconsider the whole project because I have had to allow for new ideas being incorporated later.

my question arose from a story I'm writing in which a character, Alan, sees something that he knows is impossible. this presents an internal conflict, his sensory perception organ saw something his consciousness says is impossible, and the story is about how he resolves this conflict. humans as a species don't like these conflicts and so we tell ourselves stories to resolve them which is where conspiracy stories, flat earth society, UFO's and ghost stories come from, these are attempts to reconcile events we cannot properly account for. at least some of them are, some of these folk are just attention seeking liars and some of them need medical help, but a lot of them are just confused by and unable to reconcile different things they think they know.

one of the options I want the reader to consider is that Alan is living in a simulated universe. so naturally I was thinking about who created the simulation, and why, and why it would matter to them that Alan didn't know he was in a simulated universe, and what they hoped to get out of simulating a universe and what the fact that they had simulated a universe could tell us about them.

but you guys took that simple question and ran with it in lots of very interesting directions so I want to say thank you for that. some examples that stand out are...

Simulation might be a part of nature. Perhaps folk who think on it should look to ways it might be happening in nature, rather than via computation. — Punshhh

many years ago when I was a small boy who had first heard about molecules I had this idea that our universe could be a molecule in the toenail of a giant. I don't know why it had to be his toenail, but there you go, and it fascinated me for a while. I'm not sure that a naturally occurring phenomenon can strictly speaking be called a simulation, unless you want to think of a polar bear as a particularly inept simulation of a pussy cat, but this is a stunningly original idea that I will have to spend a lot of time thinking about and will probably return to again and again. thank you very much.

The ones inside it are presumably the ones who made it. — Nils Loc

this suggested to me that Nils was thinking of something completely different, but I was not able to figure out what he was imagining, and that, on its own blew my mind. what was he thinking about, how could a civilisation construct their own universe? this was a very difficult problem for me and I spent a long time thinking he meant that they had copied their own universe so that the people inside the simulation were simulations of themselves rather than their actual selves.

within my story this would not seem to work because the simulated people would know whatever the real people knew, so they would know that they were simulations and hence Alan would not be conflicted. "oh, that weird thing I saw, that's okay, it was just the simulation raster being out of step." end of story.

but that helped me focus on what was important and necessary for my story. thank you.

It reflects progress and expectation. To simulate a universe in which the civilization is reflected implies uncertainty on the part of the creators. Man is looking for ways to survive, so then the simulation will reflect overlooked damaging properties. If these are identified (due to the revealing nature of complexity), updates become eventually applied, ending in absolute resolution. — Francesco

this really helped me to focus on the civilisation doing the simulating, who they were and why they were doing this and why there needs to be urgency to their work and what motivates them and drives them. before this post they were just cookie-cutter characters that were in my story because I needed a villain, but after this post they became people with hopes and dreams the reader can sympathise with so that you might in some sense want them to succeed. the reader is now conflicted because she can no longer be certain, is Alan a victim, or is his suffering necessary for the survival of a whole civilisation?

when a quantum leap breaks the symmetry of progress, it would be like discovering prime numbers in nature. Usually this implodes the symmetrical decimation into natural standards which is of course impossible as we do not understand the nature of time fully. — Francesco

this interesting insight created a new strand to my story where the simulators no longer agree on why they are doing the simulation in the first place. some of them think of it as a survival strategy, while others see it as pure science. this is like Elon Musk's Mars mission, he thinks he is building a rocket for going to Mars but I doubt there is a single human prepared to get in it and actually go there but the science aspects of it with reusable rockets and landing stage one boosters vertically on a floating barge 200 miles out to sea are utterly fascinating.

Its easy to model singularity, but nobody in the simulation has ever actually seen it, let alone construct it in the beginning with a beginning. — Francesco

this is a very interesting point because as far as I am aware, singularity has three or four different definitions, and Francesco could be referring to more than one of them. singularity is the point at the centre of a black hole to which everything inside the event horizon is attracted. and singularity is also the (fictional) point at which a human consciousness merges with a computer. and singularity is also a hypothetical point in time at which technological growth becomes uncontrollable and irreversible. and there was this one time at band camp... maybe later.

How much experience of this universe led you to consider this universe to be a universe? — Key

this is an extremely interesting question and is at the heart of Alan's problem. how much information is required to make something true. I've never been to New Zealand but I am reasonably sure it is there, to the extent that I would be prepared to say that Wellington is the capital of New Zealand, and I would even say that it is a fact. but I can't prove it beyond the intellectually challenged process of "appeal to authority." so if my knowledge of the universe is merely stuff I read in books why don't Never Never Land, Santa Claus and the Tooth Fairy also exist? the characters in my story will have to wrestle with these questions once Alan reveals to them his suspicions.

If you allow for the possibility of beings being able to traverse dimensions then you have a means to solve the conundrum of how the creator of a universe can inhabit that universe. A being creates a three dimensional universe while inhabiting a fourth, or fifth dimensional universe. Then steps down to become present in the three dimensional universe via some appropriate vehicle (a human body).

I cannot begin to express how grateful I am for this. it isn't relevant to my story because the creators are not fifth-dimensional beings, but it helped me see how other posters were approaching the question and what other possibilities there are I had not previously considered. really helpful, thank you.

What do you mean by "those"? Is my World of Warcraft character it's own person now for some reason? — Outlander

in my naivete I thought that "those" were quite obviously the inhabitants of the simulation. without getting bogged down in a philosophical quagmire they think they are real but are not. I don't play World of Warcraft but I would hazard a guess the characters in it don't think of themselves as being real. but the question is not silly or trivial because once again it revealed to me that there are other ways of looking at this, and that diversity of view points has been, far and away, the most valuable contribution so far. thank you, all of you.


Kaarlo Tuomi