Do We Live in a Simulation? Chances Are about 50–50

October 13, 2020 7:18 PM

It is not often that a comedian gives an astrophysicist goose bumps when discussing the laws of physics. But comic Chuck Nice managed to do just that in a recent episode of the podcast StarTalk. The show’s host Neil deGrasse Tyson had just explained the simulation argument—the idea that we could be virtual beings living in a computer simulation... “

Do We Live in a Simulation? Chances Are about 50–50

...If so, the simulation would most likely create perceptions of reality on demand rather than simulate all of reality all the time—much like a video game optimized to render only the parts of a scene visible to a player. “Maybe that’s why we can’t travel faster than the speed of light, because if we could, we’d be able to get to another galaxy,” said Nice, the show’s co-host, prompting Tyson to gleefully interrupt. “Before they can program it,” the astrophysicist said, delighting at the thought. “So the programmer put in that limit.”

posted by y2karl (165 comments total)

It's society. They work for each other, Morty. They pay each other. They buy houses. They get married and make children that replace them when they get too old to make power.
posted by Your Childhood Pet Rock at 7:31 PM on October 13, 2020 [22 favorites]

David Kipping (the astronomer mentioned in the article) has a youtube channel, where he discusses why You're Probably Not a Simulation, among other things, all aimed at a non-scientist audience. Also, here's his paper on the subject, if that's more your jam.
posted by surlyben at 7:32 PM on October 13, 2020 [2 favorites]

Do I live in a simulation?

Depends entirely on what I think the referent of "I" is.
posted by flabdablet at 7:39 PM on October 13, 2020 [8 favorites]

I always think these arguments in favor of the universe being a simulation run into the anthropic principle i.e. if reality is a simulation then we must be the prime subject of the simulation. It seems just as likely (that is, not very) that the universe is just a side effect of some unimaginably complex algorithm.

Like, imagine humanity advances to the point where we can simulate climate for centuries in advance over the entire planet, and through some quirk in the programming a scale replica of downtown Manhattan occasionally shows up on one of the beaches, made out of sand, with tiny crabs running up and down the miniature streets. We’re like those crabs thinking that we are the subject of the whole exercise.
posted by um at 7:45 PM on October 13, 2020 [22 favorites]

I think that the simulation hypothesis must have a corollary crappy simulation hypothesis. Given how much more common it is for a program to be a buggy piece of bloatware garbage held together with wishful thinking and duct tape than it is for a program to be a shining jewel of engineered perfection, the logic of the simulation hypothesis seems to imply that we are almost certainly living in one of the crappy simulations.

I would expect people to be constantly clipping into a wall and then launching into orbit.
posted by surlyben at 7:46 PM on October 13, 2020 [52 favorites]

As a computer scientist I reject universe simulations as impossible, unless the base reality has radically different rules than our universe. Physicists are too casual about extrapolating to computers with unbounded capabilities.

Physical computation is constrained by the speed of light, the laws of thermodynamics, the halting problem, and P != NP (...probably). Quantum computers do not appear likely to break any of these walls.
posted by allegedly at 7:48 PM on October 13, 2020 [21 favorites]

I would expect people to be constantly clipping into a wall and then launching into orbit.

that would be the Bethesda universe in which light contact with a stationary car would mean instant death
posted by um at 7:50 PM on October 13, 2020 [6 favorites]

If this is a simulation, the best explanation for 2020 is that this guy is playing it.
posted by flabdablet at 7:50 PM on October 13, 2020 [5 favorites]

SELINA: In reality, I have no reality Ben, you’re the one who suggested we all live in the Matrix.
KENT: M’am, nobody chose to live in the Matrix.
SELINA: What?!
KENT: The machines rose up and placed humans in the Matrix so they could use them as a biological power source.
BEN: Well, whose side were you on?
posted by They sucked his brains out! at 7:56 PM on October 13, 2020 [4 favorites]

“So the programmer put in that limit.”

BUG: gravity is very weak compared to other basic forces.
Functions as designed. [Closed]
BUG: Higgs field gives mass to particles when should have zero mass potential
Too much inertial debt. No plans to change. [Closed]
BUG: universal constant appears to be significantly off.
Perhaps will address in a future release [Open]
posted by jabah at 8:12 PM on October 13, 2020 [35 favorites]

I would say chances are about 0. It's an anthropocentric origin myth, Pascal's Wager updated for the VR age.
posted by Saxon Kane at 8:15 PM on October 13, 2020 [75 favorites]

It could be that the universe is a simulation, but the chances almost smell like lazy thinking "the options are yes or no, so it's 50-50!"

It could be that the universe is strongly deterministic modulo whatever randomness comes from quantum effects, and it could be that free will is an illusion born of the latency between a foregone subconscious decision and our conscious awareness of the closure of the option space, but if this whole universe is a simulation, I will have strong words for the unethical bastards who run it. Words, I tell you. Strong ones.
posted by tclark at 8:16 PM on October 13, 2020 [8 favorites]

Geeze, what if the universe is a simulation running as optimized code somewhere inside the universe, such that it is nested inside itself. I guess that would make it reentrant *and* Turing complete. haha
posted by jabah at 8:23 PM on October 13, 2020 [2 favorites]

In other words, it assumes that the universe exists and functions in a way not only comprehensible to humans, but in fact in a way analogous to human existence, and for a human purpose. Instead of an invisible Patriarch who punishes and rewards based on whether you please him, a god-like computer run by Scientists who punish and reward based on who know what criteria.

Also, anything that excites Elon Musk so much can't be all that worthwhile...
posted by Saxon Kane at 8:23 PM on October 13, 2020 [18 favorites]

I thought geometry was supposed to let me beat that evil demon. I guess uncertainty and modern linguistics killed that dream. Damn. Then again, Plato tried to lead us out of the cave, and he always seemed to distrust print. It's just that the dialectic that gets preserved tends to come from the people with the biggest armies and guns. Shit sucks man.
posted by eagles123 at 8:25 PM on October 13, 2020 [1 favorite]

the chances almost smell like lazy thinking "the options are yes or no, so it's 50-50!

Oh most def. This headline is straight out of How to Lie with Statistics.
posted by Saxon Kane at 8:26 PM on October 13, 2020 [8 favorites]

I could have sworn that the Raëlians believed something like this, but Googling for it doesn't bring anything up. There was some story that I read about a guy who encountered some humanoids who visited him in a UFO and told him how they were actually the architects of reality and he was living in a programmed simulation. There was some kind of infinite regression of simulations within simulations and it was humanity's task to create the simulation for the beings in the next level down.

One interesting thing to me about simulation theory as a thought experiment is whether it would be a bottom-up "emergent" simulation where the programmers just run a simulation of bazillions of particles and iPhones and pizza pies fall out of it or whether it's a top-down one with "level-of-detail" where objects like people and trees etc exist as explicit constructs in the program, and what that would mean for reductionism/nominalism etc if it was real. Maybe some kind of universals-agnostic LoD algorithm is possible?
posted by L.P. Hatecraft at 8:29 PM on October 13, 2020 [3 favorites]

Do We Live in a Simulation? Chances Are about 50–50

I'm not going to read the article because I really really am enjoying assuming that they arrived at this figure from a Monte Carlo analysis, and I'm pretty sure digging any deeper will disabuse me of that notion.
posted by aubilenon at 8:29 PM on October 13, 2020

In the sim the chances are 52-48. Now which is which.
posted by sammyo at 8:40 PM on October 13, 2020

If this universe is a simulation, then I am the only real person in it (for certain values of "I"). And there are a lot of things in it I would NOT be proud of.
posted by oneswellfoop at 8:41 PM on October 13, 2020 [1 favorite]

I've always felt the universe is more of an aquarium on something else's shelf.
posted by Fupped Duck at 8:54 PM on October 13, 2020 [5 favorites]

This is no simulation. This dirt is real. (on my office shelf)
posted by valkane at 8:55 PM on October 13, 2020

I mean seriously, I should vacuum, but, it's like a kitchen without an exhaust fan; everything sticks.
posted by valkane at 9:01 PM on October 13, 2020

If we accept the universe is a simulation, and that the humans (and aliens) modeled in the simulation are real sentient beings who are capable of suffering pain, then whoever is running the simulation is the greatest monster in the entire universe.

Of course the simulated universe research proposal would never get past an institutional review board!
posted by monotreme at 9:05 PM on October 13, 2020 [7 favorites]

As much fun as realitease films can be (death to the demonness Allegra Geller and so forth), this topic always frustrates me because "simulation" is such a crude metaphor for the concept it's attempting to describe that it instantly derails the whole train of thought.
posted by Lonnrot at 9:06 PM on October 13, 2020 [6 favorites]

I do like that 'rendering distance' concept, since it makes a kind of bridge for some old deity arguments.
If your simulation runs at a level where each -galaxy- is a discrete Virtual Machine, then all you need to do to partition them - or keep each set of ants in their own ant farm - is set c as a constant, turned down really low. Light speed schmight speed, they'll never get far. No worries about crossing the datasets.

It also puts things in perspective for people who are narcisistically thinking of simulation as some sort of Interventionist God. If you're simulating at Spiral_Cluster_2_final_master_rev2, then your individual existence isn't some malicious kid's copy of the Sims 3 where you're being attentively tormented. You're a procedurally generated pixel of 8-bit coral in the Dreamcast MAME cabinet port of Ecco the Dolphin, in a folder in a folder somewhere in an old Dropbox account that somebody set up three career changes ago and couldn't begin to guess the password to. The Heat Death of the Universe is just bitrot, or the final powering off of the Zune Music Marketplace servers.
An accounting for the universe, the Ultimate Answers you seek, don't even exist at that granularity. Don't get so worked up about it.
posted by bartleby at 9:10 PM on October 13, 2020 [13 favorites]

Imagining the 2020 content patch getting review bombed on higher dimensional Steam.
posted by Reyturner at 9:26 PM on October 13, 2020 [4 favorites]

Perhaps the way the "programmers" approach this problem is to build a GAN. On the one hand there is a neural network generating fake universes (think Descartes' "evil demon") and on the other is another network (us) trying to spot the fakes from the inside, training the demon to produce better and better quality simulations. Each simulation ends when the fake is spotted.
posted by L.P. Hatecraft at 9:27 PM on October 13, 2020 [3 favorites]

Each simulation ends when the fake is spotted.

THIS IS THE BAD PLACE
posted by curious nu at 9:33 PM on October 13, 2020 [27 favorites]

the reason there is an upper speed limit on matter--the speed of light--isnt so cosmic alien programmers have time to render the next galaxy over. it's because of the anthropic principle: in a universe that formed without a cosmic speed limit, things could travel at infinite speed and affect each other instantaneously, so there would be no cause and effect, and therefore no such thing as time, and therefore no such thing as us.
posted by wibari at 9:34 PM on October 13, 2020 [9 favorites]

I'm not going to read the article because I really really am enjoying assuming that they arrived at this figure from a Monte Carlo analysis, and I'm pretty sure digging any deeper will disabuse me of that notion.

So a researcher gave each option (A: there are no world simulations, and B: there are world simulations) a prior probability of 50% each; and then updated this probability based on the fact of simulations not being able to create other simulations infinitely (at some point you run out of computing power) which tipped things slightly in favor of our not being simulated.

So there is an idea that given a certain level of confidence in the existence of world simulations, it's actually slightly more likely than this that we're in base reality. I think that's interesting, and probably the real result in the analysis in question. But assuming the two options are equally likely is dubious. Most A/B pairs of events/non-events (rolling a 6 vs not rolling a 6, for example) are not going to be 50/50.
posted by solarion at 9:38 PM on October 13, 2020 [1 favorite]

"The Universe is a simulation" is not an explanation, it's a de-explanation because it replaces something we can explore and try to understand with a mystery in a wrapping we can never pierce.

People who believe it are trying to sneak God in by a back door.
posted by jamjam at 9:49 PM on October 13, 2020 [31 favorites]

If we're living in a simulation, it's being played by one of those sadists that would wall their Sim into a tiny oubliette with no doors or windows, just so they could watch the Sim pee themselves and then starve to death.
posted by His thoughts were red thoughts at 9:49 PM on October 13, 2020 [2 favorites]

Already covered.
posted by flabdablet at 9:54 PM on October 13, 2020

Pascal's Wager updated for the VR age.

No, that's Roko's Basilisk.
posted by justsomebodythatyouusedtoknow at 9:59 PM on October 13, 2020 [6 favorites]

So a researcher gave each option (A: there are no world simulations, and B: there are world simulations) a prior probability of 50% each

That's an awful lot of prior to hand out, for something about which we have no evidence or information.
posted by They sucked his brains out! at 10:01 PM on October 13, 2020 [1 favorite]

a creation myth, like any other
posted by StarkRoads at 10:05 PM on October 13, 2020 [3 favorites]

Ultimately, we're all just brains trapped in bone jars driving meat robots.
posted by hippybear at 10:10 PM on October 13, 2020 [16 favorites]

Hey! I'll have you know that "I" am really slow lightning, trapped in a meatball, inside a bone jar, riding on top of a monkeypigmeat mecha.
posted by bartleby at 10:20 PM on October 13, 2020 [11 favorites]

Ugh, simulationism. I hate this idea, I think it's extremely boring and uninformative but it seems really good at attracting attention from otherwise-clear-minded people. There's a sort of reductio ad absurdum response to statistical (or really, frequentist, since Bayesianism doesn't necessarily lend itself to this type of thinking) arguments for the idea that we're living in a simulated reality, which goes like this:

Beginning as with the normal simulation argument, suppose it is in fact possible for an advanced civilization to simulate a universe. It should then also be possible to simulate, to whatever degree of accuracy required, a smaller fraction of that universe while retaining the detail required to be consistent with what we experience. E.g., simulate only a single solar system in detail, and the radiation to it from the rest of the universe only to the level of detail necessary to produce correct results for observers in the solar system. These simulations would have commensurately lower computational (and thus energetic) expense, and thus should outnumber the complete ones, not requiring as sophisticated a civilization to produce. Thus it's more likely that we'd be in one of these partial simulations, rather than a complete simulation: this is basically the same reasoning as the normal simulation argument.

But if that's true, it should also be possible to simulate just the conscious creatures within the simulation, including their experience of a simulated environment and their interactions with each other, again for much lower computational and energetic expense. So by the same reasoning, "consciousness-only" simulations should outnumber simulations of large chunks of the universe, while still being consistent with our experiences, and it should be more likely that we'd be in one of these simulations. But if that's true, then it should be even easier to simulate just one single consciousness and its experiences, which would still be consistent with my experience.

So following the (frequentist) statistical argument for our being in a simulation, it should be more likely that I'm in a simulation that consists of only me, rather than in a simulation consisting of me plus other consciousnesses plus maybe other physical stuff, or being in the original, unsimulated reality. But now I've basically arrived at solipsism, in that I'm the only thing that exists as far as the level of reality that I exist at is concerned, and if I'm prepared to accept solipsism, isn't it more parsimonious to assume that I really am just the only thing that exists, and dispense with the strange edifice of being the sole thing within a simulated reality? Why bother positing the existence of a physical reality that simulates my existence when I don't even accept the real existence of the physical reality that seems apparent to me?

Philosophical solipsism isn't a position I can disprove, but it is one I find boring and unproductive. The statistical argument for our existence being a simulation seems to me to naturally lead to a less-parsimonious version of solipsism, which is enough to make me reject it. I also reject it on other grounds (e.g., it invokes a Bayesian-like "belief" interpretation of probability for its first step, asking how likely it is that it is possible to simulate a universe like ours, then proceeds in a rigidly frequentist fashion from there, and presumes that the answer to the first step is a non-zero probability), but the solipsism is enough to make me stop considering it further.
posted by biogeo at 12:04 AM on October 14, 2020 [43 favorites]

Something about the simulation argument rubs me the wrong way. Or, more accurately, the people who get really excited about it (Musk, Musk worshipping friends, etc) piss me off. It seems like most of the people advocating it (or pushing it, or bringing it up ad nauseam) are at once desperately looking for a post-religious “meaning” to a world now that they’ve gotten to a point where a traditional faith in a deity doesn’t fit them anymore. They can’t stand the idea of meaninglessness, and need something to replace their creator myth so they have a reason to keep going, keep getting up every day. Fine. Whatever floats your boat.

The problem with the simulation argument to me seems to be that the people who are pushing it the most are also the ones most likely to behave in a repulsive and shitty manner because “it’s all just a simulation” and so they don’t have to worry about consequences, as at some point some being will hit the reset button and it will all happen again. It’s like someone watched Groundhog’s Day too many times and fell in love with the scenes where Bill Murray’s character, already an asshole at the beginning of the film, begins lashing out and behaving terribly, and thought that was the best part of the film, the meaning to take away. It’s gamifying reincarnation, but without consequences for our actions.

Essentially, the people that I’ve seen who are most into the idea of a simulation are the ones who are most likely to accept all of the benefits of society, yet chafe at any concept of responsibility or need to act as a part of it. Libertarians, taxes are theft assholes, Fountainhead fanboys. People just looking for an excuse to stop “behaving” or “following rules.”

The most recent interaction I had with one of these folks, I said, well, what’s the point? If it is a sim, or it isn’t, what changes? It just turned into a lot of dog whistling and hinting at not having to play along. For most people who are into this, to me, it seems the green light to behave horribly is the end goal of the argument, and it’s just beyond tiring to see the same bullshit brought up in different guises.

If people are so desperate to believe in a prime mover, there’s a ton of religions out there. Feel free to pick one. It doesn’t make you any more sheeplike or weak to believe in an ineffable sky god than it does to believe in a programmer running a simulation, though it is telling that programmers seem to be really in tune with the idea that reality is run by... programmers.
posted by Ghidorah at 12:17 AM on October 14, 2020 [36 favorites]

Something something man makes god in his image.
posted by biogeo at 12:29 AM on October 14, 2020 [1 favorite]

There's a reddit joke in /r/nfl, and I can't find it, but a Patriots fan (the Elon Musks of the sport world) spent several paragraphs arguing in complete earnest about something along the line of a team wasn't that great if you took out this game or that game, and then further discounted the wins against easy teams because those don't count and finally you come up with a statistic that says they aren't a good team. It all makes sense and the original comment wasn't a joke, up until the end and you realize where they're arguing something completely absurd like Mahomes isn't a good quarterback he just gets lucky with really good throws time and time again, where you're like okay then he's the luckiest guy ever so what is the difference between good and lucky? This feels like this.

This is like proving there's a God using mathematics. It just isn't what it is there for. Stop abusing math. If there was something simulating us it wouldn't be a galaxy sized cluster running alien version of AWS, it'd be something so incomprehensible we probably wouldn't even use the word simulation to describe it. If people want to sit around and think about that please sign up for sophomore year theology, I have a bunch of books and a bong that made me think of those things.

Besides everyone knows if we were a simulation we just need to keep adding penrose tiling until we overflow the memory.
posted by geoff. at 12:33 AM on October 14, 2020 [8 favorites]

I'm all for discussing the simulation hypothesis as a question of metaphysics, but never as a question of ethics. Or what Ghidorah said.
posted by destrius at 12:39 AM on October 14, 2020 [1 favorite]

You have to watch out very carefully for the people who use Simulation to say
"None of this [cultural programming] is real. WE can do whatever WE want!"
vs
"None of it is real. _I_ can do whatever _I_ want!"
or even worse
"None of YOU are real. I can do whatever _I_ want."
posted by bartleby at 12:41 AM on October 14, 2020 [5 favorites]

So following the (frequentist) statistical argument for our being in a simulation, it should be more likely that I'm in a simulation that consists of only me

This reads to me as a completely fair description for any conscious understanding of reality. Which is, of course, exactly why I made that glib remark earlier about the importance of being clear about the referent of "I".
posted by flabdablet at 12:52 AM on October 14, 2020

Something about the simulation argument rubs me the wrong way.

Speaking as a fellow Boltzmann brain, I concur.
posted by flabdablet at 12:54 AM on October 14, 2020 [1 favorite]

if we were a simulation we just need to keep adding penrose tiling until we overflow the memory

They already thought of that. That's why they made boredom a thing.
posted by flabdablet at 12:55 AM on October 14, 2020 [3 favorites]

But there's plenty of human culture that is already simulatory of reality itself, the concept goes back to the Platonists! 'Is this real or is it a fake' being a question that misunderstands exactly what is going on, is not new and has been comprehensively answered by the practices and culture of wrestling, where the key concept is 'kayfabe'— maintenance of the real-unreal is key to enjoyment and credibility of the spectacle. It's not suspension of disbelief (in the sense that the match is a simulation of a sport, or fiction), because they're real throws, it's quite literally that the categories of 'simulacrum' and 'real' aren't relevant to what is going on

[Suddenly I am hit with a folding a chair by Jean Baudrillard, who has been tag teamed in by Guy Debord. The umpire counts me out while the crowd chants 'the Iraq War never happened']
posted by Fiasco da Gama at 1:38 AM on October 14, 2020 [9 favorites]

If people are so desperate to believe in a prime mover, there’s a ton of religions out there. Feel free to pick one. It doesn’t make you any more sheeplike or weak to believe in an ineffable sky god than it does to believe in a programmer running a simulation, though it is telling that programmers seem to be really in tune with the idea that reality is run by... programmers.

It's not really the same. People who are interested in the idea of reality being a simulation don't pretend that someone is more morally virtuous for believing in it, they don't threaten people who don't believe in it with eternal torture to bully them into accepting it and they don't claim with false certainty that it's true. Most people who discuss it don't even "believe" in it, they just think it's an interesting possibility to think about it. It's true that it's a clichéd idea by now, which is like OMG totally lame right? but you know, I've never heard that put forward as an idea against believing in God.
posted by L.P. Hatecraft at 1:59 AM on October 14, 2020 [6 favorites]

I've always felt the universe is more of an aquarium *on the backs of* something else's shelf turtles all the way down.

ftfy!
posted by y2karl at 2:08 AM on October 14, 2020 [1 favorite]

Since he was a strong believer in and exponent of hypostasis, which "is the underlying state or underlying substance and is the fundamental reality that supports all else", it's actually Tertullians all the way down.
posted by jamjam at 2:27 AM on October 14, 2020

this seems like just another way of coping with or rationalizing that the climate is on the verge of becoming unlivable... a responsibility dodge to say "oh well just a sim... no harm done really"
posted by kokaku at 3:32 AM on October 14, 2020 [1 favorite]

I'd like to see an actual philosopher analyse these simulation arguments.

It seems to me very reminiscent of St Anselm's Ontological Argument for the existence of God. It also seems to me that it's also vulnerable to Kant's objection to that argument that "Existence is not a predicate". You can't just take the existence of something (God, Future Superbeing) assumed in the argument, and then conclude its existence based on that argument.

But I'm not an expert on philosophy so I'm not quite certain.

Most of the other people engaged with this argument don't seem to be experts on philosophy either though, and I'm not convinced they're able to deal with this kind of slippery logic correctly.
posted by TheophileEscargot at 3:42 AM on October 14, 2020 [4 favorites]

L.P. Hatecraft, you might be surprised. What we're calling "simulationism" here is still very new, theologically speaking. There *is* a group of more hardcore believers who *do* threaten eternal torture for unbelievers. It's the already mentioned Roko's Basilisk.

I think you'd find that most Christians don't really believe in eternal damnation either, at least not in any literal sense.
posted by dbx at 4:15 AM on October 14, 2020 [2 favorites]

Simulation Argument was originated by professional philosophers and has been discussed by them.

From what I’ve seen, the strongest objection is this: The problem with the argument, and the similar Doomsday Argument, is that you should not actually put a uniform distribution over all possible humans. This sneakily hides the very unreasonable assumption that the future can alter the past. In fact the number of future humans/sims depends on what happens now.
posted by vogon_poet at 4:21 AM on October 14, 2020 [2 favorites]

In Jonathan Lethem's 2009 novel "Chronic City", one of the main figures - Perkins Tooth - makes a point that at the moment a simulation would gain the ability to run a simulation - which itself could develop to run a simulation-, the exponential effect on power usage in base reality would quickly lead to the simulation being shut down.

Kipping even explores the question of why we aren't using simulations ourselves if we are simulated by a simulation-capable base reality. He makes the analogy that we make movies mainly about contemporary subjects (I'd say this is already questionable) and therefore base-reality would make simulations about their contemporary capabilities (how is a simulation like a movie?). His shallow thinking on the subject makes him miss Perkins Tooth's simple point.

(I have no real opinion on yes or no...I just don't like Kipping's lazy logic.)
posted by patrick54 at 4:22 AM on October 14, 2020

the exponential effect on power usage in base reality would quickly lead to the simulation being shut down

A simulation's conception of power usage is simulated and is therefore insignificant on "base reality", whatever that is. That's a problem with basing a theory on something untestable, it's easy to come up with anything.

As Pauli probably would have said, this sort of thing is worse than wrong: it's not even wrong.
posted by They sucked his brains out! at 4:45 AM on October 14, 2020 [2 favorites]

A parable that illustrates the flaw in the "uniform at random from all possible human minds" assumption (proposed by Nick Bostrom, who is generally a proponent of this stuff but is quite intellectually honest):

Eve and Adam, the first two humans, knew that if they gratified their flesh, Eve might bear a child, and if she did, they would be expelled from Eden and would go on to spawn billions of progeny that would cover the Earth with misery.[12] One day a serpent approached the couple and spoke thus: “Pssst! If you embrace each other, then either Eve will have a child or she won’t. If she has a child then you will have been among the first two out of billions of people. Your conditional probability of having such early positions in the human species given this hypothesis is extremely small. If, one the other hand, Eve doesn’t become pregnant then the conditional probability, given this, of you being among the first two humans is equal to one. By Bayes’s theorem, the risk that she will have a child is less than one in a billion. Go forth, indulge, and worry not about the consequences!”
posted by vogon_poet at 4:52 AM on October 14, 2020 [6 favorites]

I actually find the theory somewhat compelling, but end up in agreement with some of what biogeo and Ghidorah are saying upthread (and forgive me if I'm misconstruing your words): it's pretty boring. Our being in a 'real' universe vs. being in a simulated one doesn't answer any of the philosophical or scientific questions about that universe. If I have a physical copy of a book and an ebook of the same edition, the story I read from them is the same, regardless of how the words are delivered to my eyeballs.
posted by papayaninja at 5:37 AM on October 14, 2020 [1 favorite]

On the one hand these kinds of Big Ideas reflect a precious, deeply human curiosity and longing for understanding, on the other it stimulates the vanities, mandibles, & salivary glands of uncultured STEM-cheerleaders who love to hear themselves talk

Anyways, as I was saying, and I refer you to diagram 14 of last week's hand-out, ...

< increasingly incoherent, spittle-flecked speculation >
< fade to black >
< fade in logo — "mothers against metaphysics" >

posted by dmh at 5:39 AM on October 14, 2020 [4 favorites]

Simulation Argument was originated by professional philosophers and has been discussed by them.

I had a look on /r/AskPhilosophy and it does seem to have been discussed a lot. They mostly just seem to take the Positivist line that it makes no observable difference if we're in a simulation so it's not worth discussing. That's valid if you're a positivist but feels a bit disappointing somehow. Where's Captain Metaphysics when you need him...
posted by TheophileEscargot at 5:55 AM on October 14, 2020 [1 favorite]

I'm far less scholarly and eloquent than most in this thread, but as a technologist (like many Mefites) find this notion absurd, ridiculous, far-fetched, and frankly impossible.

It's not that I can't use my imagination to pretend we presently live in a futuristic sci-fi world where technology and human/alien intelligence are advanced beyond what our simple brains can currently fathom. And that the tech in our simulation lags far behind that of the parent reality. Sure, it sounds like a great premise for a novel or movie.

But I can never accept that there's even a .001% chance of this being literally true, or somehow possible/feasible. Working with the details of technology every day keeps me grounded. And the level of detail, nuance, subtlety and complexity in our experienced reality is far beyond anything technology can ever simulate, regardless of what advancements may occur in the next thousands or even millions of years. Maybe I'm just dense, but I say it's impossible.
posted by TreeHugger at 5:56 AM on October 14, 2020 [7 favorites]

I've never understood the prominence of these OCD-ish moments in western philosophy.
Whether it's shadows in a cave paranoia, or deception by a demon paranoia, or ultra super simulation paranoia (or flat earth paranoia for that matter).
It always just makes me wonder why these 'thinkers' don't question their uncomfortableness with doubt, or their obsession with certainty even when spinning what-if yarns of the scifi variety.
posted by Harry Caul at 6:06 AM on October 14, 2020 [8 favorites]

On the one hand these kinds of Big Ideas reflect a precious, deeply human curiosity and longing for understanding,

There's somewhere in Kant where he waxes about the tragic predicament of humanity as thinkers, in that we are compelled to pursue metaphysical questions about the ultimate nature of the world that our intellects are not capable of answering. But Kant does not think it is possible to escape from this, and, although we cannot resolve metaphysical disputes that go beyond all possible experience , we can't entirely turn our backs on them either, I think they become Regulative Principles of Pure Reason or something, as the first Critique concludes in a flurry of hand-waving.

They mostly just seem to take the Positivist line that it makes no observable difference if we're in a simulation so it's not worth discussing.

Wasn't there an actual physics paper, a few years ago, that tested if there was some kind of like fundamental pixelation level, that would be a consequence of simulation? You can pound the table and say there is no empirical distinction between a simulated and non-simulated Universe by definition, but I don't find that entirely convincing. Maybe there is - how should I know?
posted by thelonius at 6:11 AM on October 14, 2020

In any given simulation, the probability of the maintainer getting bored and entering cheat codes to unleash tornadoes, hurricanes and Godzilla on the populace invariably approaches 1 over time.

So, yeah, this checks out.
posted by delfin at 6:20 AM on October 14, 2020 [4 favorites]

“The only value of this world lay in its power - at certain times - to suggest another world.” ― Thomas Ligotti, Songs of a Dead Dreamer.
posted by SPrintF at 6:24 AM on October 14, 2020 [3 favorites]

"Do we live in a simulation?" is the "How many angels can dance on the head of a pin?" of the 21st century. And just as useful and meaningful.
posted by fimbulvetr at 6:50 AM on October 14, 2020 [5 favorites]

What is God created the universe, but didn't notice, like a piece of sawdust in my wood shop.
posted by hypnogogue at 6:59 AM on October 14, 2020

I would say chances are about 0. It's an anthropocentric origin myth, Pascal's Wager updated for the VR age.

Pascal's Gamer
posted by showbiz_liz at 7:01 AM on October 14, 2020 [1 favorite]

If there was something simulating us it wouldn't be a galaxy sized cluster running alien version of AWS, it'd be something so incomprehensible we probably wouldn't even use the word simulation to describe it.

This, exactly. The whole "we're inside a simulation but the programmers can't program the next galaxy and also we can make them run out of computing power" business just seems like such a weird thing to believe - like "the simulation" would be run by Very Large Humans using Unimaginably Huge Desktops or something. If anything, it seems a bit like evangelical christianity -the idea that you can understand exactly what god is like because god is just a giant, slightly improved You.
posted by Frowner at 7:09 AM on October 14, 2020 [17 favorites]

Neuroscience had known for a long time that of course we live in a simulation. Reality is created by our brains as an approximation, and things like schizophrenia (or more benignly, optical illusions) show How the simulation breaks down.

So the answer is really 100%, just not in the way most people talk about it.
posted by CheeseDigestsAll at 7:19 AM on October 14, 2020 [16 favorites]

This, exactly. The whole "we're inside a simulation but the programmers can't program the next galaxy and also we can make them run out of computing power" business just seems like such a weird thing to believe - like "the simulation" would be run by Very Large Humans using Unimaginably Huge Desktops or something. If anything, it seems a bit like evangelical christianity -the idea that you can understand exactly what god is like because god is just a giant, slightly improved You.

I think there's an additional implication of "if we can hack our own reality then we can KILL GOD and BECOME GOD," which is of course the literal goal of the Musks of the world.
posted by showbiz_liz at 7:22 AM on October 14, 2020 [3 favorites]

What the hell difference does it make if we're in a simulation?

"Oh, if we figure out that we're in one, we can break out!"

Okay, so you don't think the simulation designers expected that? When was the last time one of our simulations broke out? That's not how computers work.

Honestly, all this talk about simulation theory just feels like circle-jerk intellectual wankery. It's coming up with proofs of the existence of god except for atheists. Speaking as an atheist, I am exhausted by both proofs of the existence of god that don't change anyone's mind, and the counter-proofs that also don't change anyone's mind. It's just jerking off and dickwaving with no utility to the world. Who gives a fuck? "Do we live in a simulation?" is the shit you talk about when you're stoned with friends, not a valid field of science or philosophy worth giving any serious consideration.
posted by SansPoint at 7:28 AM on October 14, 2020 [7 favorites]

I was under the impression that we definitely lived in a simulation because our meat suits are such poor interpreters of the underlying realities. - We perceive things that are not there and fail to perceive things that are. We believe we have free will but operate mainly on instinct. We have a whole section of our brain devoted to coming up with theories for what is going on but which is designed to return to default algorithms and patterns e.g. jealousy, competition, altruism etc. All that and we have a built in self destruct so that no one individual can ever progress beyond a blink of time. In geologic terms we are a thin scattering of organic compounds on the surface of the world. We will probably leave less evidence of our existence than the layers of limestone deposited in the Carboniferous Era that were once marine animals.

I don't understand why we would need a conspiracy theory or a watchmaker lurking in the background to make this a simulation. My first high school physics class that taught me that there are more empty spaces than particles and that solids are really my perception of force fields created by electrons taught me that this is a simulation. Everything I think, believe and do is an illusion. It's nothing but mathematics which is itself nothing but poetry.
posted by Jane the Brown at 7:30 AM on October 14, 2020 [4 favorites]

How have none of these people ever read "The Unpleasant Profession of Jonathan Hoag?"
posted by aspersioncast at 7:37 AM on October 14, 2020 [3 favorites]

Echoing Jane the Brown, of course we're in a simulation - our puny brains are simulating something coherent and approachable from the messy incoming blather and faulty organic pathways we call our senses and thoughts.
posted by aspersioncast at 7:41 AM on October 14, 2020 [1 favorite]

"Existence is not a predicate". You can't just take the existence of something (God, Future Superbeing) assumed in the argument, and then conclude its existence based on that argument.

So Kant was just telling them to not beg the question, then. That's why I end up with:

Honestly, all this talk about simulation theory just feels like circle-jerk intellectual wankery.

Even the good-faith conversations I've been in, or pieces I've read, haven't indicated what would be at all informative about knowing we're in an elaborate simulation: will it help me live a more content, fulfilled life? Will it teach me how to better handle unexpected tragedy (or success)? At some point in my life, most philosophical/existential/spiritual questions started needing some practical reason to continue occupying space in my mind and thoughts, for me to continue engaging with them, and if an esoteric, abstract idea about reality or existence doesn't actually yield anything actionable or helpful, then I just don't have patience for it.

And then there's this, which is objectively, materially true:

Reality is created by our brains as an approximation

To quote the gone-too-soon poet-lyricist Eyedea, "...we don't know the meal, we only know the menu that our brain tells us is real."*

* - that whole track is great, he uses swallowing powdered water to represent the mind's ability to hold paradox, and to prep the listener for the existential perspective he's about to drop. Existential truth with a beat, way more enjoyable than reading Kant.
posted by LooseFilter at 8:09 AM on October 14, 2020 [1 favorite]

I see alot of comments about how this is stupid and we shouldn't even be talking about it. How about all of you then go read and talk about something else while the rest of us (some possibly stoned) have fun talking through this thought exercise?
posted by LizBoBiz at 8:12 AM on October 14, 2020 [1 favorite]

LizBoBiz: I have no problem with it as (potentially stoned) goofing around. It's when people start taking it seriously, throwing money that could be better spent on solving real problems, at trying to "break out of the simulation" that I start to get twitchy. Though, to be honest, I don't even think there's much to it as a goof. There isn't much meat on the idea for me to sink my teeth into for fun, no matter how altered my state.
posted by SansPoint at 8:23 AM on October 14, 2020 [2 favorites]

what would be at all informative about knowing we're in an elaborate simulation: will it help me live a more content, fulfilled life?

No, but it will give you total mastery over simulated cutlery.

I have no spoons.
posted by flabdablet at 8:38 AM on October 14, 2020

I saw this on SG-1. They all had helmets.
posted by clavdivs at 8:48 AM on October 14, 2020

I saw this on TNG. We're waiting for holodeck Moriarity and his girlfriend to fly their shuttle here.
posted by cmfletcher at 8:56 AM on October 14, 2020 [3 favorites]

I saw this on Adventure Time. Bmo had a disco.
posted by Insert Clever Name Here at 9:12 AM on October 14, 2020 [1 favorite]

I think it's unfair to call the simulation hypothesis nothing but wankery; some fairly serious philosophically-inclined people have weighed in on it at various times, and it does provide an interesting explanation of what seems to be odd—or at least very convenient—values of some fundamental constants and other observed behaviors of the Universe. The alternative, I suppose, is the Anthropic Principle (both strong and weak variants), which is similarly untestable. So you have, on one hand, the idea that we might be living in a simulation which has been consciously designed (by somebody, or something) to support life, explaining the convenient choices of constants etc., but then punting on the intelligent-life question to the "base layer" containing the simulation: why do they, whoever they are running the simulation, exist in their non-simulated Universe? That's the issue I have with it: it doesn't seem to answer a question, but inserts an additional level of complexity into the explanation without relieving any of the complexity. But that's far from saying that it's totally stupid.

My first high school physics class that taught me that there are more empty spaces than particles and that solids are really my perception of force fields created by electrons taught me that this is a simulation. Everything I think, believe and do is an illusion. It's nothing but mathematics which is itself nothing but poetry.

Except the Universe doesn't run on math, as far as we can tell. Keep in mind that math is merely a way of describing observed phenomena and predicting outcomes within certain bounds. If you throw a ball up in the air, highschool classical physics will let you predict its trajectory pretty darn accurately, but it's not like the ball is crunching the numbers. The math is just a convenient way we have found to describe and predict reality; it is not reality itself. The reality of why the ball moves in a certain way is a lot more complex and comes down to the interaction of fundamental forces, and if you keep tugging at the strings gets you to "well, we don't know exactly" and hand-waving about the Large Hadron Collider pretty darn quick.

One of the problems I have with some branches of physics is that they seem to have lost the forest of reality for the trees of mathematics; forgetting that the math is not really fundamentally explanatory. It's just a language for describing observed behavior and predicting future behavior, within certain bounds (e.g. classical physics falls apart when the objects are too small).
posted by Kadin2048 at 9:30 AM on October 14, 2020 [11 favorites]

Except the Universe doesn't run on math, as far as we can tell.

I don't know if I agree with this...

Either the laws of physics are in theory computable by a Turing machine, or they aren't. (You don't need a quantum computer -- classical computer can simulate with 2^N blowup.)

If they aren't -- that's really weird! That would be saying it's physically possible to decide undecidable problems -- it just feels intuitively wrong. Super-Turing computation is, by my intuition, something that makes absolutely no sense.

If they are -- then you might as well say the universe is a big Turing machine computing a physical simulation. Modulo all the thorny philosophical problems of what it means for a computation to be "about" something.

This is the kind of stuff that makes the simulation argument seem more plausible to me, although I don't actually really give it any credence. The probabilistic arguments, at least in every form I've seen, are fatally flawed, and I wish the refutations would spread as fast as the arguments themselves.
posted by vogon_poet at 9:54 AM on October 14, 2020 [1 favorite]

I saw this on Gunsmoke when Matt Dillon morphed into the Thing and unable to draw a gun, lurched around getting shot up ad infinitum.
posted by y2karl at 10:14 AM on October 14, 2020 [2 favorites]

Either the laws of physics are in theory computable by a Turing machine, or they aren't. And the circular reasoning has returned.
posted by Harry Caul at 10:24 AM on October 14, 2020 [2 favorites]

some fairly serious philosophically-inclined people

ANALYTIC philosophers, though -- who seem to me to be trying to make a metaphysical argument based on "logic" while jettisoning metaphysics more generally.
posted by Saxon Kane at 10:30 AM on October 14, 2020

The simulation idea is too skeptical for me (if I can't trust my sense of reality all bets are off), but I like the idea of a lazy universe. That's a simulated universe in which the simulator only simulates that which is absolutely necessary for observations in the simulated universe to make causal sense. So when nobody looks at the moon, it's still there, just a little bit less, in the sense that the simulator doesn't have to run the code where we look up at the moon, and see faces in it, and shoot rockets at it, etc. etc. The moon is still there in that it causes tides and everything else, but if you could look at it while nobody was looking at it (which you can't), then you would see a bit of nothing where the moon used to be.

Perhaps on a more abstract level, let's say the simulator has different levels of detail for different regions in spacetime, and it only keeps as much detail per region as necessary to ensure that all observations within and between the regions are consistent, with the speed of light functioning as a kind of causality cop. Something like that would explain how the position of a particle is indeterminate before you measure it, as up until that point there had been no need for the simulator to simulate all the steps that result in you getting a number on a piece of paper representing the particle's position. Contrariwise, when you get the simulator going on the process of simulating the invention of all of science and the setting up of measurement equipment, then sure, the simulator will produce a number on a piece of paper that is the measurement of the position of the particle. However from the point of view of the simulator neither the particle nor the measurement really "exist", except as emergent expressions of simulation rules.

I don't think things actually work that way, and in any case it's unclear how you could tell the difference, so pragmatically it's moot. But the underlying conceit of the universe being not people or objects or fields, but somehow constituted of pure data or relationship-stuff and informational complexity, is fascinating.
posted by dmh at 10:33 AM on October 14, 2020 [1 favorite]

dmh: That's just solipsism with extra steps.
posted by SansPoint at 10:42 AM on October 14, 2020 [1 favorite]

Look, we aren't in a simulation because there aren't any glitches. There are "bugs", yes, but no malfunctions. Ever. Every single thing we have ever observed across the universe, no matter how weird (i.e. seemingly bug-like) always obeys the basic laws of nature (math and physics). Nobody, ever, in all of recorded history, has found 8 bananas in their bag when they only put in 6. Never have we observed a single star among all the hundreds of thousands we have documented for which the red shift isn't quite as red or quite shifty enough as predicted by math. It all always, always, always adds up. We've never seen a dead pixel.

That's ridiculous, ok? Any reality in which intelligent beings are capable of producing and maintaining perfectly glitch-less hardware is a reality so alien that it cannot be understood. Just. NOPE.
posted by MiraK at 10:42 AM on October 14, 2020 [10 favorites]

MiraK just what I remembered from the last... oh gosh deja vu, now there's a glitch for you.
posted by sammyo at 10:59 AM on October 14, 2020

That's a simulated universe in which the simulator only simulates that which is absolutely necessary for observations in the simulated universe to make causal sense.

George Berkeley? George Berkeley to the white courtesy phone.
posted by justsomebodythatyouusedtoknow at 11:06 AM on October 14, 2020 [1 favorite]

From what I’ve seen, the strongest objection is this: The problem with the argument, and the similar Doomsday Argument, is that you should not actually put a uniform distribution over all possible humans.

This is the problem I've always had with it. If I understand it correctly, the theory is that if it's possible to simulate the universe, and humans have reached a point that they're capable of simulating the universe, then they will likely simulate millions of universes and so if there's only one "real" universe and millions of simulated universes, then we're mostly likely in one of the simulated ones.

But that implies that when a consciousness is created they roll some dice to determine whether they end up in the real universe or a simulated universe, which doesn't really make sense.
posted by ultraviolet catastrophe at 11:11 AM on October 14, 2020 [2 favorites]

That is because as simulations spawn more simulations, the computing resources available to each subsequent generation dwindles to the point where the vast majority of realities will be those that do not have the computing power necessary to simulate offspring realities that are capable of hosting conscious beings.

This part is not true. In simulation theory, it is totally possible to fit larger/more complex universes inside of smaller ones...you just run the simulation slower. (And there are many reasons to create a slow-motion simulation...humans do it all the time.) If you are inside the simulation, there is no way to compare the flow of time with the 'outside' universe, and time seems totally normal. Hell, we could simulate our universe now with the computing we have available. Each frame might take millions of years to generate, but to those inside that would pass in a split-second. It's also unnecessary to do 'corner-cutting' by only simulating the observed part, just throw more processing time at it.

Also, can we just drop the whole 'Elon Musk and his buddies are really into this so it must be bullshit' strawman argument? It's tiresome. Stop it. Yes, people who want to believe in something are usually a hot mess, but some of us want to discuss this subject without being denigrated, so just cool it, ok? Our universe has just been proven to be infinite, by a seven sigma confidence, spatially, by the smoothness of the cosmic background radiation, and theoretically infinite probabilistically (quantuum many-worlds theory) (although, honestly I wouldn't be surprised if those two things weren't linked in some way related to 'exact copy distance' theory). There is no reason to believe that it cannot be infinite in other ways, some of which we may never even dream of. Again, this is not something I'm wishing for, it's simply a possibility that can't be ruled out, even if those possibilities can't necessarily be proven. And sure, without proveability, this might all be irrelevant, but it's still interesting.
Nature does not just abhor a vacuum, it utterly loathes it. (while at the same time creating so much more vacuum, in the voids between galaxies, constantly. Lol.) And if you need proof: look around.
posted by sexyrobot at 11:11 AM on October 14, 2020 [8 favorites]

Now the moon argument is a good one. Just 'turn on' the moon when you're looking at it. But unless this is a full on solipsistic argument (and you may be a NPC but I'm a primary:) what's the cost of turning on the moon node for every player, every camera, every reflection and every video of a reflection of a reflection of the moon all over everywhere vs the ultra-meta-programmers just leaving a chunk of rock in orbit.

Certainly gets conceptually trickier below the subatomic level where the strings seem to be more like data than anything at a physical perception that we can hold in our hand. Think about the deep underlying nature of all this stuff, which can barely be thought about using math that seems almost impossible to translate into regular language must really alter some folks perceptions.
posted by sammyo at 11:12 AM on October 14, 2020

oh gosh deja vu, now there's a glitch for you.

Pshaw, that's like saying the dead pixel on my monitor is evidence that we're in a simulation. Your blitzed neurons didn't break the laws of nature! The universe never glitches.
posted by MiraK at 11:16 AM on October 14, 2020

(Sorry if the 'infinite universe' seemed a non sequitur...I was referring to universes nested inside each other, possibly infinitely, possibly without a 'base layer', and possibly with multiple/infinite branches (ie multiple simulations inside one universe))
posted by sexyrobot at 11:28 AM on October 14, 2020

So when nobody looks at the moon, it's still there, just a little bit less, in the sense that the simulator doesn't have to run the code where we look up at the moon,

I guess this does explain where the Loch Ness Monster goes. He stops being rendered. Fish too at the bottom of the ocean, and Morlocks and earthworms in my garden. They are rendered just in time for me to cut them in half when I am digging.
posted by The_Vegetables at 11:34 AM on October 14, 2020 [1 favorite]

I usually enjoy bullshit thought experiments like this one, but this concept is irritating to me. We have always created new theories about existence and the world around us based on our current technological advances and scientific discoveries. That we have computers and are building AI is cool and all, but how limited do we need to be to assume that whatever entity we are building as "god" is only capable of creating us with the limits of what we can imagine right now? In 20 years, who knows what our technology will be able to do? Maybe one or two iterations beyond what is possible now, perhaps. The whole, "We're just living in a computer game," nonsense is entertaining, but I'm not buying it.

Everyone knows that humans are a virus.
posted by Chuffy at 11:40 AM on October 14, 2020 [1 favorite]

> I've always felt the universe is more of an aquarium on something else's shelf.

Well, this seems as good of a place as any to promulgate my theory that the universe is a Tupperware in someone's fridge; it's not so much "expanding" as it is bloating; and one day the owner is going to open it up, notice that one planet has gotten all green & fuzzy and maybe a little crusty in spots, and will post a can-I-still-eat-it to AskMe.

Maybe just keep this in mind the next time you're tempted to say "cut off the bad bits and enjoy the rest", ok?
posted by Westringia F. at 11:44 AM on October 14, 2020 [4 favorites]

The surest proof against solipsism is that solipsists feel compelled to describe their beliefs to other people.

In this discussion we have several arguments that simulationism and solipsism are fundamentally the same thing. Those arguments are very valuable to me, because it means that I can waste my time on more interesting problems than simulationism without any guilt.
posted by fantabulous timewaster at 12:22 PM on October 14, 2020 [5 favorites]

Name me any major philosopher who has argued for solipsism. Berkeley believed in God and other minds; you can just assume that philosophical idealism is the same thing as solipsism.
posted by thelonius at 1:01 PM on October 14, 2020

If there is more than one mind in the simulation, you do not have solipsism.
posted by thelonius at 1:07 PM on October 14, 2020 [1 favorite]

The universe is simulation running inside our own heads.
posted by storybored at 1:16 PM on October 14, 2020

Yes, but applying the logic of the statistical argument for simulation, simulations with only one mind should be more common than simulations with more than one mind, because they'd be easier to run, and so a mind reflecting on its own existence is more likely to be part of a simulation in which it is the only thing being simulated than to be part of a simulation with multiple minds. That's the reductio argument.
posted by biogeo at 1:20 PM on October 14, 2020

I have no spoons.

That's because there is no spoon.
posted by nickmark at 1:29 PM on October 14, 2020 [1 favorite]

That's because there is no spoon.

What kid would waste his time bending imaginary spoons instead of imagining a giant flying dog and going Never-Ending Story on an unsuspecting public? The matrix is a lie, held down by production budgets and a story that only involves kicking shooting and punching digital bits.
posted by The_Vegetables at 2:03 PM on October 14, 2020 [2 favorites]

So if I were to, say, jump off of this very tall building, what are the possible outcomes?

1) I could crash into the street below and die instantly on impact.
2) I could turn out to have the power of flight and fly safely around without hitting the street at all.
3) I could turn out to have the power of phasing, and could phase safely through the ground.
4) I could turn out to have the power of elasticity and just bounce off the street.
5) I could turn out to have the power of immortality and actually survive hitting the street.
6) I could turn out to have the power of instant regeneration and just heal from hitting the street.
7) I could turn out to have the power of teleportation and blink to safety before I hit the street.
8) I could have the power to create objects with my mind and create a huge soft cushion to land on.
9) I could have the power of incredible luck and just happen to land in the back of a passing mattress truck.
10) I could turn out to have the power of matter transmutation and turn the street into soft down feathers.
11) I could turn out to have the power to turn into a bird or maybe a flying dinosaur and fly away.
12) I could turn out to have the power to summon a rocket suit to encase me and land safely.
13) I could turn out to have the power to call upon angels who would save me.

...

Guys, I'm pretty sure I have superpowers! I mean the odds are approaching 100 percent!
posted by Naberius at 2:13 PM on October 14, 2020 [6 favorites]

Hmm I don't follow the one mind argument. If I were the advanced civilization trying to answer an important question, I would need to simulate the society and the interrelations between minds. This is nature nurture epistemics: your simulation needs to do the actual work computing the thing you're trying to observe or extract, but minds are not developed independent of their environment.

I do think simulations in which conscious minds suffer are unethical. I wouldn't be surprised that humans eventually are able to create primitive but sentient computers, I would need a good reason why that is not computationally possible.
posted by polymodus at 2:17 PM on October 14, 2020 [1 favorite]

Yes, but applying the logic of the statistical argument for simulation, simulations with only one mind should be more common than simulations with more than one mind, because they'd be easier to run, and so a mind reflecting on its own existence is more likely to be part of a simulation in which it is the only thing being simulated than to be part of a simulation with multiple minds. That's the reductio argument.

Only if you assume the purpose of the simulation is to simulate minds. Consciousness could just be the byproduct of a physics simulation.
posted by pugg at 2:19 PM on October 14, 2020

Maybe a good example is neural nets. Neural nets are successful by virtue of their interconnections. Each individual node is not that interesting or computationally complex. Hence the need for hardware to process large graphs. Simulating society itself as a graph will yield more information than a single person in a faked environment, like a Device Under Test conditions with faked input vectors.
posted by polymodus at 2:23 PM on October 14, 2020

it's simply a possibility that can't be ruled out

I guess? It's also a "possibility" that is so unlikely and meaningless that there's no reason to accept the (very, very weak) starting assumptions.
posted by Saxon Kane at 2:25 PM on October 14, 2020 [3 favorites]

it'd be something so incomprehensible we probably wouldn't even use the word simulation to describe it.

I like this!

Clearly we are in a simulation, the parts aren’t even hidden! It’s built out of gluons and quarks and so forth.
posted by bjrubble at 3:04 PM on October 14, 2020 [1 favorite]

it's simply a possibility that can't be ruled out

I guess? It's also a "possibility" that is so unlikely and meaningless that there's no reason to accept the (very, very weak) starting assumptions.

What's the point of this comment other than to be dismissive? If you don't want to discuss the theory, then why are you here?
posted by sexyrobot at 3:32 PM on October 14, 2020

This is discussing the theory. The theory is bunk, and Saxon Kane has pointed out a huge reason why.
posted by SansPoint at 3:39 PM on October 14, 2020 [1 favorite]

man I can't wait til the next religion/fan-fiction/whatever thread where I get to sneer openly at people who just want to have a fucking harmless conversation
posted by um at 3:48 PM on October 14, 2020 [2 favorites]

In no way have they done that. Instead they made some bs conflation of this theory with solipsism as if simulation theory had anything whatsoever to do with humans and human intelligence, and then posted an (admittedly classic) article about statistics to 'disprove' the yes, totally click-baity, '50-50' claim.
The idea that humans have any special place in this universe is ridiculous. Earth takes up exactly zero percent of the universe. We are as much a side effect in any theoretical simulation as we are if this was the 'base' universe. Nobody is claiming that this simulation is in any way designed to model us. As near as I can tell, it's modeling an entire universe, using the smallest amount of 'rules' it can to generate as much detail as it can. The fact that we have intelligence is the merest side effect of that. To suppose otherwise would be arrogant.
To put it in simpler terms, simulation theory is much more about 'No Man's Sky' than it is 'the Matrix'

I didn't see this posted earlier, but the quote that always struck me was "as the number of simulations IN our universe (maps, models, etc) goes up, the likelihood we live in the 'real' one goes down." ...I'll see if I can dig up one of the latest models we've made.. ah here.
posted by sexyrobot at 4:22 PM on October 14, 2020 [2 favorites]

Calling out problems with a philosophical idea is what you do if you take it seriously. I think simulationism is a bad idea predicated on poorly-considered premises, for reasons I gave above, but it's a solid, clearly-articulated idea, which merits engagement, even if, in my case, that engagement is to say that I think it's a bad idea and give some reasons why. I don't see this type of engagement as "sneering" at people who don't agree with my take, but rather an invitation for others who disagree with me to provide counter-arguments. I'm surprised at the comparison to, say, fan-fiction, which is an activity that invites an entirely different sort of engagement than a philosophical proposal does. I'm not personally interested in fan-fiction discussions so I probably wouldn't even enter those threads as I would have nothing of value to contribute. Is it not acceptable to critique fan fiction according to the standards and expectations of the genre in a discussion here? In a thread on a philosophical topic, saying "this is why I think this idea is bad" seems to me to be an entirely legitimate form of engagement, even an expected one. I'm surprised to learn that some people see this as inappropriate and sneering.
posted by biogeo at 4:22 PM on October 14, 2020 [4 favorites]

The simulation hypothesis is somewhat interesting, though I think the statistical arguments some use to "prove" we are living in a simulation is bunk. I don't find insubstantial dismissiveness to be very interesting, but long form dismissiveness founded on reasoning beyond "I don't like that one guy who very publicly promotes the simulation hypothesis" is much more interesting and even appropriate for the discussion.
posted by wierdo at 4:28 PM on October 14, 2020 [1 favorite]

I don't think that was directed at you, biogeo,...outside of your 'otherwise clear-minded people' dig, you were not dismissive, nor a total dick about it...it's absolutely fine to disagree, like I disagree with:
These simulations would have commensurately lower computational (and thus energetic) expense, and thus should outnumber the complete ones
I think it's actually easier to create a complete universe that unfolds from simple rules than one built around exactly modelling, say, Earth. And, given enough 'mass' to work with, you may end up with those specific models anyway. I would strongly suggest looking into 'exact copy distance' theory for insight on this. Plus, as near as I can tell anyway, it may have been recently proven with the latest planck satellite data on the background radiation...in which case 'head blown', as the kids say.
posted by sexyrobot at 4:36 PM on October 14, 2020

well, I don't like the Plato's Cave thought experiment neither.
posted by ovvl at 4:40 PM on October 14, 2020

I guess the point I'm making is that many here are not even trying to engage with actual simulation theory, they are attempting to debunk some 'matrix'-like VR theory where there's like a conscious person building a house around you to try to trick you or something, which is something else entirely.
posted by sexyrobot at 4:49 PM on October 14, 2020

Like if Schrödinger used prussic acid and looked to quick.
posted by clavdivs at 4:58 PM on October 14, 2020

Well, the problem with simulating a complete universe is that computation is physical, as I noted in a previous thread on this topic (and here is the paper I cited there). All information processing entails an increase in entropy, and the amount of information processing a system is capable of performing is limited by thermodynamics. The information content of a simulated universe cannot be greater than the information content of the computational system performing the simulation. So to create a simulation, either the "resolution" of the simulation needs to be reduced in some way so as to require less information, or the scope of the simulation needs to be reduced, so that the computational system can actually handle the information required within the constraint of its thermodynamic limits. As far as our current understanding of physics permits, this is a hard requirement, so any simulation must be constrained in at least one of these two ways. The more strongly restricted the simulation, the smaller the computational system and the lower its entropy footprint, which is the basis of my argument that more strongly restricted simulations should be more common than more weakly restricted ones, which leads to the reductio argument.

Nobody is claiming that this simulation is in any way designed to model us.

I'm not sure this is true. As I understand it, when Nick Bostrom formulated the simulation argument, it was specifically with the idea in mind that these were "ancestor simulations," something a hyper-advanced civilization would use to study its own history. A non-anthropocentric version of this argument seems reasonable enough, but I think the original formulation was much more limited in scope.
posted by biogeo at 5:06 PM on October 14, 2020 [6 favorites]

if I can't trust my sense of reality all bets are off

I recommend experimenting with ketamine.
posted by flabdablet at 5:21 PM on October 14, 2020 [1 favorite]

The universe never glitches.

Treating every apparent glitch as a research opportunity helps with that.
posted by flabdablet at 5:35 PM on October 14, 2020 [1 favorite]

I talked about that in an earlier comment...you can just run the simulation slower to increase your detail level and even model larger universes than the one you are in. To those inside time seems perfectly normal because there is nothing to compare it to...unless you cut some sort of window to the outside, I guess. (And now I'll probably be thinking about the implications of 'universe windows' for the next several months lol)

Yeah it's come a long way since Nick Bostrom. And (and I am not an expert on this) I don't know if the 'thermodynamics of computing' can be used to rule out future computational advances. I'm not sure if it's been disproven since, but David Deutch apparently proved that as long as a computation is 'reversible ' it requires zero energy. (I'm not sure if every kind of computation is reversible fwiw) Like if you make an abacus out of frictionless surfaces, then the moving of the beads requires energy, but you get it back when the beads fall back down. (This is from 'Minds, machines, and the multiverse, the search for the quantuum computer, which I thought I had here, but apparently not, grar). Apparently this is one of the yet-to-be-realized promises of quantuum computing, energy-free calculations! But yeah, there will probably still be energy losses until such a time as we get our hands on frictionless surfaces, or the electronic equivalent.
posted by sexyrobot at 5:45 PM on October 14, 2020

No, you can't get around the complexity of the simulation by running it slower. Our intuitions about how computers work can lead us astray when we're talking about computing near its physical limit. The entropy requirements are actually completely insensitive to how fast or slow the computational system performs its calculations: for a certain amount of information processed, there is a certain increase in entropy required, period. You need a certain amount of free energy to run a simulation, and that is finite for any computational system. (It's necessary to consider, e.g., the power source as part of the computational system for this purpose.) We might posit this to be incredibly vast for an advanced civilization, but it's still finite, and minute in comparison to the amount of information in the entire universe. Running the simulation slower just means it takes longer before the computational system runs out of free energy to perform the calculations.

And it may be true that there are computations that can be performed in an energy-neutral manner, in fact I think that would seem to be necessary. But the key here isn't energy, it's entropy, and there's no beating the Second Law of Thermodynamics. This isn't about the "thermodynamics of computing," it's about just plain thermodynamics, and many physicists now consider the statistical mechanics of information and entropy to be more certain than any other known physics. Hypothesizing that there could be some future advances to computing that circumvent known physics takes us firmly into the realm of unconstrained speculation.
posted by biogeo at 6:15 PM on October 14, 2020 [3 favorites]

Perception does not encompass reality: check.
Life is like a dream: check.
Some guy running a puppet show that is our perception: not-check.
posted by ovvl at 6:21 PM on October 14, 2020 [1 favorite]

There is a very strong case that this universe is not a simulation that can be made within the simulation hypothesis.

Because there's no argument you can make to the effect that our universe is a simulation that would not also apply to the universe in which we are a simulation, and so forth on up. Therefore, to say we are a simulation immediately invokes the existence of an infinite nested hierarchy of simulated universes.

The only escape from this is for the simulationist to say 'hey wait a minute, of course there must be a universe which is not a simulation where it all started.'

To which I would reply 'OK, you admit there must be at least one universe which is not a simulation, so at this point since we don't know whether it's even possible to produce a simulation universe, but we do know there is a universe which is not a simulation, the only reasonable conclusion is that this universe which we know exists is not a simulation until and unless you can produce a simulated universe, or otherwise prove such a thing is possible.'
posted by jamjam at 6:33 PM on October 14, 2020 [6 favorites]

Running the simulation slower just means it takes longer before the computational system runs out of free energy to perform the calculations.

Oh yeah, absolutely. It could run out of juice at any time (and yeah the whole universe runs out of energy eventually, anyway, right? Nothing is forever.) AND we don't know when it started...not necessarily at the 'beginning'. Also, keep in mind that the universe as a whole violates basically all the conservation laws, right? You can't create or destroy energy or matter, right? Ok, then how did we end up with an infinite amount of both? (Infinite. The universe is infinite.) All scenarios somehow involve a self-creating infinite fountain of energy, whether or not that fountain takes the form of a 'big bang' or a 'base universe'. Normally I would say let's apply occam's razor and not create extra entities, and only have the one universe, but I'm not sure that applies when you have infinity fountains feeding a thing that has historically only become more infinite and complex.
TBH, the most staggering thing about this whole dumb place is how crazy conservative it is when it comes to the number of rules, and how utterly maximalist it is in like, every other way.
posted by sexyrobot at 7:03 PM on October 14, 2020 [1 favorite]

the only reasonable conclusion is that this universe which we know exists is not a simulation until and unless you can produce a simulated universe, or otherwise prove such a thing is possible.'

Here you go! Right here.
posted by sexyrobot at 7:08 PM on October 14, 2020

Nobody, ever, in all of recorded history, has found 8 bananas in their bag when they only put in 6. Never have we observed a single star among all the hundreds of thousands we have documented for which the red shift isn't quite as red or quite shifty enough as predicted by math. It all always, always, always adds up.

I don't believe we're in a simulation (Who would simulate THIS universe? Seems incredibly boring to me) but I also believe you absolutely cannot make this argument. Inexplicable things happen all the time. People do pull out more bananas than they remember putting in. People have spontaneously burst into flame. Indisputable evidence of UFOs exists. Many these things have rational explanations that folks eventually settle on, but saying that everything that has ever happened in the universe always adds up is stated on a level of faith that the Pope hopes to someday achieve.
posted by Mr.Encyclopedia at 7:13 PM on October 14, 2020 [2 favorites]

The only escape from this is for the simulationist to say 'hey wait a minute, of course there must be a universe which is not a simulation where it all started.'

Or the simulation simulated the "starting universe". Again, nothing's testable, so anything can be made up.
posted by They sucked his brains out! at 8:04 PM on October 14, 2020

So many thoughts on this and I'm nervous for the dimension it has in philosophy-land, where I feel always backfooted and unable to know even what's sensible. But it also has a foot in the lands of math and science, especially computer science where my professional skills lie. And there it upsets me amazingly!

It actually reminds me of Plantinga's argument that it's rational to believe in God -- a suspiciously supply-side Jesus type of God at that -- also hitched in part on a counting argument of the "universe of possible universes" organized by Baysean thinking to get at a suspiciously persuasive number that seems rational.

A lot of my arguments can be short because they've been covered already: I can assert a frequentist interpretation of probability, be on sound philosophical footing, and undercut the whole argument. And I often do: IMHO Bayeseanism goes too far as an interpretation of probability but doesn't go too far enough as a formalization of "belief", where's it critically hamstrung by the limitations of its origin in probability.

Some forms of simulationism reduce to sophistry, which has enough said about it. Others reduce to whatever that philosophical name is where God is the official Observer whose nature gives the reality observed its realness. And I'm sure enough has been said on that too.

Here we've had an interesting side discussion on whether reducing to sophistry is likely based on the computational efficiency of what parts of a subuniverse you model, and a discussion on computational efficiency and maybe slowing down the simulated time ticker to compensate for any power differential. They all set up a more technical objection I've formed: I can dick around with the numbers and posit that half a universe's computing resources are needed to simulate a subuniverse at the scale of a million years to compute one microsecond. At best time is scaled 634 pentillion to one -- and the series is so strongly convergent that's basically the number: one second of time experienced by a sentient being, or a rock, or an atom, will almost likely be in the "real" universe and not in any of the infinite simulated ones. My point is not to argue that view directly, but to highlight that anyone can game those numbers to give the result they want with no more justification than I gave. And what is the value in summing over "experienced time" rather than "universe count"? Absolutely none because neither of them is scientifically justified. Naberius's joke about counting the outcomes of jumping off a tall building and using imagination to broaden the odds of good fate is trenchant. Summing over an underconstrained domain is a job for imagination, not statistics.

One last technical objection, stemming from my conversations with a physicist friend in grad school about Stephen Wolfram's book ANKOS. Now this is where the science is beyond me and I'm not confident of doing it justice, but it seems there some well-established results in the physics we know that depend heavily on space being a continuum: there is a value between any two values, a direction between any two directions, space between any two points. That nature of space comes into play in relativity, and I guess in some parts of quantum physics. And it prohibits space being discretized in something like a cellular automaton or similar mathematical structure. It has to include "irrational numbers" if even by indirect reference.

Which then means it must also include "uncomputable numbers", at least in the potential energy values of wavefunctions in certain states, or in the tensors describing the curvature of spacetime. This is a deeper problem than I think people understand since theoretical CSci isn't on the standard curricula. But if measured physics as we know it requires uncomputability our universe can't be simulated by any method we'd consider worthy of the name. It's a testable prediction that is so far tested unequivocally false.

Believe it or not there's even more, but I think it's time to get back to the human & psychological point. I have opinions on why Plantinga makes a living off crummy arguments rationalizing culturally popular religious philosophy. And I have related opinions on why "the simulation hypothesis" is so popular among certain types, especially the types who write articles like this for magazines like this.
posted by traveler_ at 9:10 PM on October 14, 2020 [2 favorites]

Okay, I swear I read all the posts, but it is late and I may have missed it.

How is the "we are agents in a simulation" theory fundamentally different than "we are characters in a book?"

Not trying to be snarky, I don't see the difference, other than simulations require processing power. But it feels like I'm missing something here.
posted by ®@ at 9:50 PM on October 14, 2020 [3 favorites]

it seems there some well-established results in the physics we know that depend heavily on space being a continuum: there is a value between any two values, a direction between any two directions, space between any two points. That nature of space comes into play in relativity, and I guess in some parts of quantum physics. And it prohibits space being discretized in something like a cellular automaton or similar mathematical structure.

Seems to me that all we're looking at there is a mathematical formalism (real numbers) specifically constructed in such a way as not to induce unnecessary artifacts or conceptual "seams" in whatever it's used to model.

I remain completely unconvinced that anything coherent can be said about how reality "truly" is, on the basis of arguments proceeding from the attributes with which we choose to endow our modelling tools; reality is what it is regardless of the tools we employ to model it. If our tools fit well, that's just us displaying advanced skills at being the liquid in the puddle.

If space is prohibited from being one way or another, then to me all that says is that space is a feature of some particular model which might or might not be the tidiest way to apprehend and summarize reality.
posted by flabdablet at 9:57 PM on October 14, 2020

Nothing, really? I think a lot of people are getting into technical details because they think technological metaphors change the questions somehow. But it's as old as 'am I a Monk who dreamed of a Butterfly? Or a butterfly dreaming of a Monk?'.
posted by bartleby at 9:58 PM on October 14, 2020 [2 favorites]

Wait y'all, if we keep talking about this will it create some kind of unsolvable loop and the simulation crashes??????

Also, this: there is a value between any two values, a direction between any two directions, space between any two points

is one of the most beautiful things I've thought about in a long time.
posted by LizBoBiz at 12:40 AM on October 15, 2020

This thread needs a Truman Show boat scene citation, I think.

(As inferred by this clip, one ironic upshot of scientifically answering the question "Are we living in a simulation?" in the affirmative would be that "Is there a God?" would also come back with "of course"; she's the poor entity in charge of paying the electricity bills, no doubt).
posted by rongorongo at 12:44 AM on October 15, 2020

I do think there's a difference when philosophers and physicists approach questions like "Are we alone in the universe?". And it is a big misconstrual by physicists to think that philosophers really believe anything, and apply science values onto philosophical approaches and questions. And frankly, professionals are some of the worst offenders when they make judgments about what is fruitful and what isn't.

So to use this example, "Are there aliens"? is a pretty boring and unscientific question. From that standpoint. But ask a philosopher and they can do some neat things with it.

And finally, we live in a pretty terrible universe, so the reminder that intellectualizing and philosophizing as a pejorative "wankery", "useless", "doesn't help me live" and so on... Maybe that's the whole point of Bostrom's lesson. It's like saying art or some small idea that for a moment captures a layperson's mind in the way NDT playfully responded in the interview, is a useless privileged luxury. It shouldn't be.
posted by polymodus at 3:30 AM on October 15, 2020

Those arguments are very valuable to me, because it means that I can waste my time on more interesting problems than simulationism without any guilt.
posted by fantabulous timewaster at 3:22 PM on October 14 [5 favorites +] [!]

Eponysterical!
posted by LizBoBiz at 4:23 AM on October 15, 2020

I don't really buy arguments that it's computationally impossible.

First, we don't know what the physics of the real universe is. They might not be future creatures doing ancestor simulations, but aliens in a completely different universe where the physics allows better computation.

Also if they're just trying to simulate conscious beings, they don't need to simulate the whole universe to a low level. They just need the brains and hormones etc of the creatures. A broad structure for whatever information the creatures hold in common. Then the sensory inputs. If one of the creatures flicks the fovea of its vision too rapidly and notices the pixels making up its hand, you could just have a subroutine edit out the memory a minute later.

The brains in question aren't that good so you only need to simulate what they're paying attention to.
posted by TheophileEscargot at 6:12 AM on October 15, 2020

I'm sorry if I missed this being mentioned above, but I think it is worth noting that Bostrom's original argument was more nuanced than just arguing that we are probably sims:

I argue that at least one of the following propositions is true: (1) the human species is very likely to become extinct before reaching a ‘posthuman’ stage; (2) any posthuman civilization is extremely unlikely to run a significant number of simulations of its evolutionary history (or variations thereof); (3) we are almost certainly living in a computer simulation. It follows that the belief that there is a significant chance that we shall one day become posthumans who run ancestor‐simulations is false, unless we are currently living in a simulation. I discuss some consequences of this result.
posted by thelonius at 6:33 AM on October 15, 2020 [1 favorite]

Nothing, really? I think a lot of people are getting into technical details because they think technological metaphors change the questions somehow. But it's as old as 'am I a Monk who dreamed of a Butterfly? Or a butterfly dreaming of a Monk?'.

This. The question is pointless because it doesn't matter. Whether we're are made of elementary particles of a simulation of elementary particles makes no difference because in either case, it's the universe we are in.
posted by CheeseDigestsAll at 7:20 AM on October 15, 2020 [2 favorites]

(3) we are almost certainly living in a computer simulation.

That does a hell of a lot of heavy lifting, considering that it's being presented as an exhaustive/exclusive list "at least one of the following propositions are true" especially because there is no logical problem with all 3 being false. Maybe none of them are true, and it does no good to embed your favored conclusion as a premise.
posted by tclark at 8:51 AM on October 15, 2020 [4 favorites]

Wait y'all, if we keep talking about this will it create some kind of unsolvable loop and the simulation crashes??????

Let me hear everybody say "hey-oh!" yeah!

All the ladies say, "yeah!"

Everybody over thirty, do this with your hands! Everybody with a red shirt, jump up and down!

Yo, everyone whose first name begins with an "L" who isn't Hispanic, walk in a circle the same number of times as the square root of your age times ten!
posted by Saxon Kane at 11:21 AM on October 15, 2020 [3 favorites]

saying that everything that has ever happened in the universe always adds up is stated on a level of faith that the Pope hopes to someday achieve

Only if you assume it "adds up" to something comprehensible to human minds.
posted by Saxon Kane at 11:24 AM on October 15, 2020 [1 favorite]

they are attempting to debunk some 'matrix'-like VR theory where there's like a conscious person building a house around you to try to trick you or something, which is Nick Bostrom's argument, and what the whole article is about?
posted by Saxon Kane at 11:29 AM on October 15, 2020 [1 favorite]

polymodius: Philosophy in general is good and important. The particular philosophical argument that we are living in a computer simulation is not good or important for reasons outlined elsewhere in this thread. It's poor philosophy. It makes remarkable leaps of logic that cannot be justified. There are holes one could drive a cruise ship through with room to spare.

There is a philosophical argument that one world stops existing when they close their eyes. This is obviously bullshit on the face of it, and a good way to test it would be to suggest someone who believes this to walk across a highway at rush hour with their eyes closed.
posted by SansPoint at 2:08 PM on October 15, 2020

First, we don't know what the physics of the real universe is.

Okay, but to repeat myself from the previous thread where this was discussed, if you're prepared to posit that the physics of a universe within which there is a computer simulating our universe is fundamentally different from our own, then we're in the realm of unconstrained speculation. Which, you know, is fine for it's own sake, but there's no basis for making any assessments or judgments, no basis for rational argumentation. You might as well posit that our universe was created by a magic spell cast by a cosmic gremlin, since that could be the "physics" of the universe that "simulates" ours. There's nothing really wrong with indulging in such ideas, but you're essentially writing fiction at that point, and there's no reason to take those ideas seriously outside that context.

This kind of gets to the heart of why I think the Bostrom-style simulationist argument, while ultimately a bad argument, is valid and useful to talk about, if only to refute it. (Though I admit the fact that so many people seem so prepared to accept it without seeming to think through its implications is frustrating to me, hence why I described it as "boring" before.) On the one hand, identifying where it goes wrong can be a useful way to think through certain concepts: what are computation and simulation, what are information and entropy and how do they interrelate, when is it valid to take frequentist approaches to probability and when is that dangerous, how do we reason probabilistically about unknowns, etc. On the other hand, it dances very close to ideas that are "not even wrong," in the sense that they are impossible to evaluate, and also don't lead one to think about these other valuable topics more deeply. Clearly delineating why Bostrom-type simulationism is well-posed (if, in my opinion, poorly-conceived) while unconstrained "simulationism" that presumes anything might be possible in the simulator's universe is not well-posed is also a useful exercise.
posted by biogeo at 2:45 PM on October 15, 2020 [4 favorites]

On the plus side, if you think a lot about quantization, some kind of simulation idea comes up very easily. Why is it that (e.g.) electron energy only comes in integers, and physicists seriously consider that space may be quantized as well? Sounds like a cellular automaton!

On the minus side... simulation doesn't address quantum weirdness at all. Why would anyone create a simulation that is non-deterministic, and where certain quantities cannot both be specified at the same time? It seems to me that the idea presupposes an EPR-style hidden variables theory (i.e. determinism), which has not done well theoretically.
posted by zompist at 2:53 PM on October 15, 2020

Well, in fairness, EPR says hidden variables are fine as long as they're nonlocal (i.e., their changes are faster-than-light), and Bell's Theorem shows that quantum mechanics is nonlocal anyway. So if something like pilot wave theory is right, that would address those objections to simulation (uncertainty relations are intrinsic to wave mechanics in general). Of course, as far as I know there still isn't even a relativistic version of pilot wave theory, but nevertheless, a deterministic version of QM hasn't been totally ruled out.
posted by biogeo at 3:11 PM on October 15, 2020 [1 favorite]

The main conceptual blockage to a deterministic QM, as I understand it, is the insistence that determinism implies in-principle predictability.

But if every part of every field and every trajectory of every particle and every relationship of every particle with any other particle is in fact unique, that's not the case. And I have never found any solid analytical argument for the idea that reality must necessarily constrained to be repeatable.

The evidence we have for repeatability is based on observations made with inherently limited precision - observations, furthermore, where we can only ever conclude that observation A is a repetition/confirmation of observation B by willfully ignoring the very things we've chosen to ignore while making those observations - coupled with a heuristic of dubious validity.

The very first step in designing a scientific experiment is working out how to isolate the system under test from its environment sufficiently well to be able to discern behaviours that we can reasonably ascribe to inherent internal causes.

The way I read quantum uncertainty is not so much as a fundamental feature of the behaviour of quantum objects per se, but as a reflection of the fact that there are some kinds of measurements that we would like to be able to do on subsystems that demonstrably cannot be completely isolated from their environments. Which, in turn, means that the conceptual act of treating reality at those scales as if it were a collection of independently mathematically modellable objects - be those particles, fields or anything else - necessarily involves approximation.

What we're looking at when we do QM is reality on such a fine scale that the only repeatability we are ever going to find is statistical. QM works with or without the principle of induction. In effect, it's a way to quantify and account rigorously for the very same inductive uncertainty that we would otherwise have to handwave away and ignore in order to construct a "classical" theory.

And if we can't even justify saying that observable A is in fact different from observable B, I can't see how we can then go on to justify saying that A causes B. It seems to me that if we're going to take the usefulness of QM seriously, we need to unclench a little bit on the primacy of causality itself in our conceptual toolkit.

This is something I'm not at all unhappy about. Causality has always been a slippery fish.

But what, I hear you ask, does any of that have to do with whether or not we're living in a simulation?

Well, it seems to me that if you're going to simulate something then the very first step would pretty much have to be to break it into simulable subsystems that your simulator can then manipulate. And it further seems to me that from inside any universe actually constructed from separable subsystems, what we would find when examining that universe at the finest scales would look like a classical theory.

I see the fact that the most successful physical theory yet found is limited to finding statistical regularities as pretty good evidence against the simulability of reality to arbitrarily fine precision.
posted by flabdablet at 5:29 PM on October 15, 2020 [2 favorites]

We don't know enough about physics or simulations to have a coherent idea of what it would even mean to be "living in a simulation", and therefore there is nothing useful we can say about it.
posted by moss at 6:04 PM on October 15, 2020 [2 favorites]

assuming we have a perfectly spherical computer in a vacuum...
posted by mcrandello at 8:48 PM on October 15, 2020

Didn't Apple release that in 2014?
posted by flabdablet at 3:25 AM on October 16, 2020 [1 favorite]

flabdablet: No, that was the cylinder. The spherical computer was announced on Tuesday.
posted by SansPoint at 9:19 AM on October 16, 2020 [1 favorite]

The simulation idea is too skeptical for me (if I can't trust my sense of reality all bets are off), but I like the idea of a lazy universe. That's a simulated universe in which the simulator only simulates that which is absolutely necessary for observations in the simulated universe to make causal sense. So when nobody looks at the moon, it's still there, just a little bit less, in the sense that the simulator doesn't have to run the code where we look up at the moon, and see faces in it, and shoot rockets at it, etc. etc. The moon is still there in that it causes tides and everything else, but if you could look at it while nobody was looking at it (which you can't), then you would see a bit of nothing where the moon used to be.

It's a rather small step to extend that to "My girlfriend only exists in full when she's attending to my needs. When I don't see her, she goes into a simplified mode."

Which, given the culture of the tech bros who like this idea, then I'm not at all sure that's not the ultimate goal of the exercise.
posted by happyroach at 4:31 PM on October 16, 2020 [1 favorite]

Urg. Real comments hurt simulated Hulk head.
posted by y2karl at 7:19 PM on October 16, 2020 [1 favorite]

HULK CRASH!!!!
posted by InfidelZombie at 7:55 PM on October 16, 2020

I think when people talk about the simulation hypothesis they're talking about things happening they would not have considered possible. I would probably have bet baby prisons were impossible, but I would definitely have bet that, having become public, they'd be shut down immediately.

They weren't.

Different people have different impossibility lines, but I think the Donald Trump presidency crossed quite a few of them (I actually considered it a possibility).

It's reality TV. It's *bad* reality TV, in that when you see a character named Reality Winner, or Karl Marx Force the Fourth, you just ... don't believe it's real.

There are people who argue the earth is flat, and they aren't going away. (They're in on the joke, they are enjoying the gnashing of teeth, etc.)

One way to process all this is to simply stop believing in random events. Reality is optimizing for lulz, and that's not a property of a random and indifferent universe after all.

(There are other ways.)
posted by effugas at 8:45 PM on October 16, 2020

@.: How is the "we are agents in a simulation" theory fundamentally different than "we are characters in a book?"

I find it difficult to take simulationism seriously because - as remarked earlier - I see no need for the reality "simulating" us to have implicit laws such as entropy, time, space, or quantization so long as these things can at least be expressed. We could be analogous to a very detailed description of an armchair. The requirement for a computer just seems like the latest in a long line of metaphors addressing this problem, with the unfortunate side-effect of the analytically-minded not understanding it as a metaphor.
posted by solarion at 4:17 AM on October 17, 2020 [2 favorites]