
Are you living in a computer simulation? [pdf] - aluket
https://www.simulation-argument.com/simulation.pdf
======
Ruphin
Theoretically there is no reason to assume that simulating the entire universe
down to quantum level as we understand it is infeasible. Perhaps the laws of
physics and nature are different in the 'real' world which allows the
existence of a system that can simulate our universe. There is no reason to
assume that physics in our universe operate in the same way as physics in the
'real' universe, if our universe turned out to be a simulated one.

The physics in a simple simulation game like Minecraft is consistent from the
perspective of inhabitants of that world. And although Minecraft is Turing
complete, from the perspective of inhabitants of that world, it would seem
equally impossible to simulate their entire universe from the tools available
within the game.

Analogous to how Minecraft is a simulation with a simplified model of our
physics, our world could be a simulation with a simplified model of 'real'
physics. There is no way to ever find out if this is the case.

To me the interesting part of this is that regardless if we are simulated or
not, it doesn't make our lives any less 'real'. Suppose we all lived in a
simulation, would that matter? We still think, feel, and operate in the same
way. It's not like The Truman Show where if we figure it out we get to escape
to the larger world. Would knowing that all this is a simulation change the
way you behave? Would you be more reckless, or more careless towards others?
Any pain we inflict, on ourselves or others, still has the same effect. I
don't see how it changes anything.

------
jere
In order to make the simulation hypothesis remotely believable, you have to
assume a dozen premises which are nonstarters. In particular:

>Simulating the entire universe down to the quantum level is obviously
infeasible, unless radically new physics is discovered. But in order to get a
realistic simulation of human experience, much less is needed

I'm glad Bostrom says simulating the universe is infeasible (most people
loosely following his argument ignore this), but I'm not convinced that
simulating an infinitesimal portion of the universe is sufficient. Rewinding
the simulation whenever one of the billions of simulated humans gets skeptical
while doing science sounds absurd and kind of defeats the purpose of a
simulation, no? In general, I don't think you can ad-hoc "fill in the details"
of a particular piece of a simulation and have it make sense because you
weren't simulating the inputs in that much detail.

I wrote quite a bit more here: [http://jere.in/the-simulation-hypothesis-is-
nonsense](http://jere.in/the-simulation-hypothesis-is-nonsense)

~~~
lidHanteyk
Indeed, the Free Will Theorem of quantum mechanics makes short work of
Bostrom's hope that it would be possible to just rewind the Universe and get
the desired outcome, as if creating a tool-assisted speedrun.

Edit: Imagine that you are simulating a qubit. You want the qubit to behave a
certain way, but it refuses to do what you want. You try rewinding it over and
over with your magic time-rewinder, but it still refuses to give you the
measurement that you expect. That's the Free Will Theorem.

Now imagine that you're simulating a human. You want the human to behave a
certain way...

~~~
naasking
The Free Will Theorem has nothing to do with anything. It doesn't even say
that people or particles have free will, it says only that experimenters and
particles have the same amount of freedom. That could still be zero, because
deterministic interpretations of QM exist.

------
hjb
Right now I suspect that I'm living in an epidemiological model with entirely
unreasonable parameters.

------
beckingz
Classic memetic hazard. Almost as potent as post-modernism.

------
the_af
I see this link has been submitted time and time again to HN, almost without
exception without attracting many comments. Occasionally it gets a "not this
again!" and "I hoped it would raise _new_ arguments".

------
Uehreka
I feel wholly unconvinced that future civilizations will _definitely_ build
ancestor simulations. I feel like a lot of these arguments do a bad job of
explaining what utility these ancestor simulations would be to the future
civilizations, and basically say something like “it will be so easy to create
such a simulation, members of the future society will just create them on a
whim for amusement.”

But given that Moore’s law has run out and there are no pathways we can see to
faster computation (we’re even starting to hit the bedrock of physics in our
search) such a simulation would probably require considerable resources. We’re
talking like, mining asteroids for silicon and indium and using immense solar
panels for energy.

Which gets me to the point that I think strikes at the heart of the argument
and kills it: A society capable of ancestor simulations would have to be
extremely highly ordered. The universe abhors order and is constantly
regressing to higher entropy states. So while the existence of such a society
may not be impossible, it would seem to be very very unlikely (and perhaps
even short-lived if it did happen), thus meaning there probably aren’t many
long-lived high-quality ancestor simulations, and thus we probably aren’t
living in one.

~~~
naasking
> I feel like a lot of these arguments do a bad job of explaining what utility
> these ancestor simulations would be to the future civilizations, and
> basically say something like “it will be so easy to create such a
> simulation, members of the future society will just create them on a whim
> for amusement.”

Why do people run the sims game today? Isn't that a waste of time even by
modern standards? Would future humans not waste time with entertainment? Look
at how much time people spend on analyzing Conway's Game of Life to find new
constructions. Isn't it plausible that future humans might play with what
parameters would have had Trump lose in 2016?

Which leads to: ancestor simulations would have significant historical
importance. How many historians today would love to simulate what would have
happened had Hitler won? Or what would have happened had one of the plots
against Alexander the Great succeeded?

Ancestor simulations would also have economic importance. We already simulate
toy economic models. However, we also know that humans aren't prefectly
rational. If one day we understand the algorithms driving human brains, why
wouldn't you run your economic simulations with real human minds for more
precision?

I could go on, but I think the point is clear. We have no reason to suppose
any of these values would change in "post-humans". They would still have
incomplete information about the world, but they would be able to handle
substantially more complexity, at the very least because of the simulations
they have available to them.

> But given that Moore’s law has run out and there are no pathways we can see
> to faster computation

There are many, many pathways forwards that are being explored (optical
computing, amorphous computing, reversible computing, etc.). Our current
architectures are in fact quite inefficient. We could be making much more use
of parallelism, for instance.

------
simonh
I'd like to pick on one particular issue related to substrate independence. I
recently watched an interview with John Searle in which he proposed that a
simulated brain would not be conscious. His reasoning was that a weather
simulation in a computer couldn't make anything wet.

If that's true then the simulation argument fails. I'm not convinced though.
It seems to me that the materialist argument, and Searle seems to be a
materialist, is that consciousness is an emergent property of neuronal
activity which is basically a form of computation. Well simulated weather
isn't weather, but computer simulated computations are actually computations.

So while I am highly skeptical of the simulation argument, I don't object to
it in this respect. Also I feel bad disagreeing with Searle as I think he gets
so much else right and has made many very valuable contributions.

~~~
naasking
Searle is definitely not a materialist, but a dualist. His take on the
simulation argument is that simulations cannot be built (possibility #1 in
Bostrom's argment).

~~~
simonh
Searle does believe that consciousness is caused by physical processes in the
brain. However he also believes in what he calls 'Biological Naturalism'
whereby consciousness can only be generated by biological systems.

So Searle does not agree that consciousness is a product of or a form of
computation, which is where he and I part ways.

~~~
naasking
His naturalism doesn't seem coherent. If no physical system can compute
incomputable functions, then it's special pleading to insist that there's a
difference between natural laws and mathematical laws.

------
Aaronstotle
I really enjoy this paper/argument, it's fairly simple and produces an
extraordinary conclusion. For anyone else who enjoys this work, he (Nick
Bostrom) also released a book called SuperIntelligence regarding
predictions/outcomes for various paths of AI.

------
doublerabbit
I do not fully believe we are in a computer simulation but more so multiple
realities exist based on your choices. Your existence is the variable, life is
the constant. And life is rendered based on the variables and constants you
give it.

Brains are the computer of the human, dummy shells we live in. The skeleton,
bones and joints are the mechanical elements, as like the engine, axel and
wheels is to a car. We know we can make alterations to our computer with drugs
which can access the control port. Whether it being LSD or Caffeine. The same
as you can with a car by adding a turbo or an induction kit.

If you take my understanding of of quantum computing where a state can either
be 0 or 1, 0 can be 1 and 1 can be 0, what's there not to say that alternate
realities can't exist at the same time?

Does even behind me even exist? If a tree falls in the woods and there is no
one around to hear it, does it make a sound?

As a thought experiment: I want to head to the supermarket. I can either take
route A by turning left out of my apartment, or I can either take route B,
turning right out of my apartment.

What happens on route A happens because I am there to witness and what would
of taken place on route B, I do not know. Would the same set of events of
occurred on that route if I had taken route B instead of route A?

Does myself being a variable alter the constants? Would the guy with the red
jacket who walked route B, when I took route A, still be walking route B if I
had taken route B initially? Or is it because I chose route A they appeared in
route B?

I do believe you can live in two realities, not at the same time as you can
only be one of yourself, sort-of; but that you can be part of both.

This was just a ramble to pass thirty minutes of my time so I can finish
working from home. But if I actually worked those thirty minutes rather then
writing a loose HN comment theory, would I later tonight do something
different then what I am going to do now. Even though I am sitting at my desk,
in the same location. If I hadn't of written this comment would the tracks in
my shuffled playlist be different to the ones I've just listened too?

------
AnimalMuppet
This paper is better than most that argue for simulation. Usually the argument
is " _of course_ advanced beings will run simulations if they can". Those
papers just assume that, and then use that assumption to reach the conclusion
that we are probably living in a simulation. This paper at least recognizes
the possibility that advanced species will not do that.

------
mofimOyt
Since the term computer and its usability has been known recently (few hundred
years, it seems fair.

What about before this "computers" ? Universe cannot be run in computer-
simulation if the term is not known before that.

Later if something else comes up, we might believe, its "that" technology

~~~
TheOtherHobbes
What's next in the series:

verbal narrative, hand-written text, manual printing press, industrial
printing press, mechanical tabulation, punched card computing, Von Neumann
computing, distributed public computing, ?

~~~
lidHanteyk
Secure distributed computing, agoric computing, room-temperature qubits,
epigenetic programming, swarm computing, civil rights for DAOs, astrophysical
electronics, Gödel machines, emulated humans, civil rights for machines,
uplifting, civil rights for sapients.

------
RivieraKid
I think it's complete nonsense. Here's a thought experiment that explains one
reason why (there are two more):

Any computer program can be executed manually by a human given that he has
access to a read/write memory. The memory can be as simple as a piece of paper
with pen and eraser, or a hard disk. So let's say we simulate the feeling of
pain in this way. When does the simulated being feel pain, when the "human
CPU" makes read/write operations? Or even when the memory is in an idle state?
If you have a large enough hard disk with the right data, is there actually
someone in pain?

In addition, there are different ways you can encode the memory data, you can
say that when this memory location is set to 0, it actually means 1, and vice
versa. This means that _any_ data on a large-enough hard disk means that some
simulated being is in pain.

------
tengbretson
This seems like a long-winded way of saying "I want to believe in God, but
don't want any moral prescriptions to come out of it."

------
ggambetta
I remain unconvinced. On some level the logic is sound. On the other hand,
reminds me of the arguments by Saint Augustine and other philosophers
"proving" the existence of God. Centuries later, we look back at these
arguments as cute, naive attempts that probably sounded very clever at the
time. I feel like we'll look back at these "we're living in a simulation"
proofs the same way.

~~~
naasking
The argument isn't attempting to convince you we are in a simulation, it's
rather laying out the only three possible outcomes:

1\. Simulations _cannot_ be built: simulations are impossible, advanced
civilizations go extinct before they're built, etc.

2\. Simulations _will not_ be built: future humans have no interest in
ancestor simulations, they have ethical qualms against doing so, etc.

3\. We are almost certainly in a simulation: the number of simulated people
far outnumber the number of non-simulated people, so you are likely a
simulation.

You simply can't be unconvinced by this argument.

~~~
lidHanteyk
4\. Simluations necessarily consume more resources than they emulate, as a
matter of computational theory. Therefore, some simulations can be built, but
every simulation loses fidelity, and below a certain threshold there are no
longer any bits being conveyed. We would only be in a simulation if there is a
pool of resources greater than that of the observable Universe, and by
definition of the latter, we cannot model the former other than to say "yeah,
it's big". So (3) doesn't grant any predictive power at all.

Crucially, we have simulated our own ancestors, but the simulation did not
appear to us to contain any sort of inner experiences from our ancestors. Is
this because we aren't modelling faithfully enough, or because there are
fundamental limits on the ability to model inner experiences?

~~~
naasking
> 4\. Simluations necessarily consume more resources than they emulate, as a
> matter of computational theory.

That's part of 1: simulations _cannot_ be built. A simulation that loses
fidelity is not a proper simulation is it?

Also, you're assuming a simulation of physics, but simulating a world of minds
is more feasible.

> Crucially, we have simulated our own ancestors, but the simulation did not
> appear to us to contain any sort of inner experiences from our ancestors.

We haven't, we have crude models compared to "post-humans" which would have a
proper understanding of the algorithms at play in the human mind.

~~~
lidHanteyk
Sorry, I don't think that people have rich internal experiences; I think that
every human is a p-zombie. Therefore when I say "simulation" I am talking
exclusively about physics simulations. All life is chemistry; all chemistry is
physics.

Nonetheless there are some elementary results that we can use. It takes more
than one qubit to simulate a qubit, for example.

The simulations I am thinking of, for example, are those which tell us our
genetic ancestry [0][1]. We can simulate the entirety of the depth of human
sexual expression, in one single dimension, in this way. So do humans _really_
have a rich internal experience relating to their sexuality? I don't know and
I can't tell, but nonetheless the simulations are possible.

Would you care to share with the class how a "world of minds" can be
simulated? How can the fidelity of a mind be measured? You appear to have
solved a lot of the Hard Problem when nobody was looking!

Edit: Ah, you can't. Good try, thanks for playing.

[0]
[https://en.wikipedia.org/wiki/Mitochondrial_Eve](https://en.wikipedia.org/wiki/Mitochondrial_Eve)

[1]
[https://en.wikipedia.org/wiki/Y-chromosomal_Adam](https://en.wikipedia.org/wiki/Y-chromosomal_Adam)

~~~
naasking
If you're a materialist, then you should accept that all of our apparent rich
internal experiences can be captured by algorithms. A "world of minds"
simulation need only run these algorithms, not the physics that underlie them.
This is many orders of magnitude simpler.

Furthermore, a simulation also needn't simulate the physics equipment we use
to test our physics. An advanced simulation of the human brain's algorithms
contains semantic content about what the individual believe these machines do,
what properties they test for, so they need only simulate the interface and
report results consistent with those properties and subject to the expected
error distribution.

You seem to be forgetting that these are post-human civilizations, so they
would have such detailed understanding of the human brain.

------
lidHanteyk
Bostrom's logic is so laughably bad, but it's worth refuting clearly.

To tackle point (1), note that Bostrom assumes a Doomsday argument [0] and
that there are both pre-human and post-human modes of life which are
qualitatively different from ours. But it assumes that the structure of the
Universe is relatively constant, and that is not the case. For example, we
live in a time when galaxies are clearly visible in the night sky; were we to
have been born much sooner or later, we wouldn't know about galaxies, and we
might further be fooled into thinking that the Milky Way is unique or special.

Point (3) is really the one that Bostrom wants for us to conclude as true, but
it's completely inaccessible and unfalsifiable. Just like Christopher Columbus
could never sail to the Garden of Earthly Delights, it's not possible for us
to falsify the proposition that we live in a simulation, whether it be a
Spinozan world, a Great Programmer world, or whatever quasireligious
interpretation one might want to use.

We can now freely embrace (2). We run plenty of simulations of pre-human life.
One might object that we do not model all of the details of the inner
experiences of such life, but of course there is no evidence for such inner
experiences and we can ignore them entirely [2].

There's other critiques of this argument. They usually boil down to some sort
of post-selection [1]: Bostrom first post-selects to insist that there will
inevitably civilizations which could plausibly simulate us, and then uses the
post-selection to lock us into already being simulated.

And, of course, there's a final argument from the outside: This would have all
been _just as true_ in the 1600s as it would be today, were the argument to be
rock-solid. But then, computers would not have existed in the societies of the
1600s, so the argument would have to be prefaced by an introduction which
doesn't just wax poetic about how tiny future computers would be, but also
explains computation, quantum mechanics, black holes, etc. However, in the
1600s, Spinoza [3] was able to put forth the argument that we are all
simulated by the mind of God, and his deductions and rules were not much
different from Bostrom's. Spinoza and Bostrom seem to have the same
conceptualization of the Universe, and are following the arguments that they
think will lead them there best. But those arguments are hopelessly and
obviously covered in the technology and ideas of the time. Therefore, if there
_is_ a way in which we are simulated, then the actual argument which proves it
will have to come with a massive introduction which justifies it, not just by
using our current words and ideas, but by introducing some sort of 25th-
century mathematics and physics.

Oh, but wait, why would simulations become possible arbitrarily in the 25th
century? We can iterate, and imagine that the hypothetical civilization which
simulates us is _indefinitely_ far in the future. When we predict this far
into the future, not only do our models break down, but our _ability to model_
breaks down. Bostrom far overshoots with this argument!

[0]
[https://en.wikipedia.org/wiki/Doomsday_argument](https://en.wikipedia.org/wiki/Doomsday_argument)

[1]
[https://en.wikipedia.org/wiki/Postselection](https://en.wikipedia.org/wiki/Postselection)

[2]
[https://en.wikipedia.org/wiki/Philosophical_zombie](https://en.wikipedia.org/wiki/Philosophical_zombie)

[3]
[https://en.wikipedia.org/wiki/Baruch_Spinoza](https://en.wikipedia.org/wiki/Baruch_Spinoza)

------
est31
I remember reading a webcomic where one protagonist brought this point
forward, concluding that most worlds are simulated and thus we live in a
simulation. The other protagonist was super annoyed and replied sarcastically
that the other person made a point, most points are false, and thus their
point was bullshit.

I thought it was xkcd but can't find it. Anyone know which webcomic it was?

~~~
rdimartino
It sounds like this [https://www.smbc-
comics.com/comic/simulations](https://www.smbc-comics.com/comic/simulations)

~~~
est31
That's it. Thank you!

