There isn't really much of a connection between this and Bostrom's simulation argument. The simulation argument is about calculating the probability that we live in a simulated universe based on certain assumptions about human behavior and technological development. Bostrom's argument doesn't make any metaphysical claims other than assuming that consciousness is substrate independent.
I don't buy into metaphysical theories that claim to deduce the existence of worlds outside our own based on armchair reasoning. We know that the physical universe exists and we can explain everything that we experience in terms of quantum field theory and general relativity. Any theory that wants to challenge this view of the world needs to modify those existing theories, or design an experiment that shows why they aren't adequate to explain reality.
Modal Realism was the inspiration for the somewhat infamous, slightly tongue-in-cheek "Possible Girls" paper where Neil Sinhababu argues that people across different modal realities can fall in love with each other (and that explains imaginary relationships)
As I understand it, the major candidates for dark matter are new elementary particles, so they would still fall under quantum field theory.
Of course, there is always the possibility that another revolution in physics happens, but even then our current theories will still be valid in most domains, in the same way that Newtonian mechanics is still valid in most domains.
> we can explain everything that we experience in terms of quantum field theory and general relativity
Everything we experience, except experience itself. Conscious/qualia/whatever is still… well, none but God knows what it is, and I have no evidence for the existence of any god let alone that one.
That's because consciousness is an emergent phenomenon, not part of fundamental physics. Every atom in your brain behaves according to the laws of particle physics, and somehow consciousness emerges out of that. Our theories of neuroscience aren't developed enough to explain it yet, but there isn't any reason to believe that there is something magical or non-physical going on.
This argument seems to mix up "existence" and "construction".
The number states do not magically appear in the physical universe merely by thinking up the construction. The numbers could be configured as (temporary) patterns in physical objects, such as brains, books, or in ink molecules on paper. But the states are not physical objects themselves.
Also, if our universe happens to be universal, in the sense that it encompasses all of existence, then how could a calculation device exist outside of it? I'm not saying this is necessarily the case, but it's an option that many simulation-believers overlook. The calculation device might be part of the existence, but it seems rather unlikely that it can then predict reality faster than it unfolds.
Much ink has been spilled by many a philosopher on the topic of whether or not numbers "magically exist." Plato was the obvious example of a philosopher who believed numbers "exist" independent of our universe. Though no one is saying they exist "in the physical universe", but it's not a given that they cna't possibly exist if not "within our universe."
Think of it this way. Graham's number is an absolutely enormous number, right? Let's assume for the sake of argument that nobody has ever computed the Graham's-number-th digit of pi. We know for certain that there is a Graham's-number-th digit of pi. And we know that if two people calculated it independently, they'd get the same digit. But (at least in this hypothetical) nobody has actually ever done the calculation to see what the Graham's-number-th digit of pi is. Given all I've said so far, the act of finding out the Graham's-number-th digit of pi seems more like an act of discovery of something that already existed than an act of invention of something that didn't already exist. So, it seems quite reasonable to many to conclude that numbers "exist."
Also, Iah's view does imply that our universe does not encompass all of existence. It also implies that no calculation device need exist anywhere.
In response to your second point, at a high level I believe the calculation device would exist inside _one_ universe but calculate another one... the idea that you could calculate your own universe and use that to predict future events does seem covered in paradoxes. For one, the universe you're predicting would (recursively) have to include the computer you're using to predict it.
... but that's different to what I've argued here. I'm not claiming the states are physical objects, but just the existing of the pattern, even if temporary or intangible, would feel real to the humans/actors inside it.
My premise was that the universe was universal, i.e. there is no other universe. Again, I'm not saying that this is the case, or that there is any reason to believe that it is so, but I don't see a good reason why there would be more than one universe. (Note that all of this depends a bit on the definition of a universe -- for the sake of argument, I'm assuming our universe to be a system closed under physical interactions. Happy to argue about other universes, but perhaps it's best to save that for another time.)
If you are trying to prove the existence of this universe by requiring the existence of another universe, then it's turtles all the way down.
How do you define "existing" of a pattern? Does it exist inside a physical thing? If so, then how does that physical container come into existence? And if it exists only conceptually, then how is it possible for concepts to exist? In the universe that I know, concepts only exist in the minds of human beings, and perhaps in some other animals. To me, it seems rather unlikely (and a bit anthropocentric or egocentric) that concepts are something truly universal.
For me, it helped to meditate a lot on what it'd be like to be a rock. The rock does not have memory, no sensory input, and therefore most likely no concept of time, space, logic, nor mathematics. It makes you wonder whether the rock exists at all. In any case, it probably doesn't care as much about it as we humans do. There might be a hint there.
> The calculation device would exist inside one universe but calculate another one...
Hmm... calculation device? I thought the premise here is that actually doing the calculation is not necessary - a tenet you invoke in order to say say elsewhere [1] that the computational complexity does not matter, as the notionally simulated universe exists anyway.
But if that were so, would it not do away with the distinction between simulating and simulated universes, creating the situation where every possible universe exists in every extant universe?
One one hand it's absurd (it means that everything that can be imagined and many more things exist).
On another hand the opposite (requiring a mapping from that computation to real-world objects) is absurd too, because for any sequence of numbers you can always find a mapping to physical objects (notice that you can make the mapping arbitrarily complex). So why require the extra steps?
My opinion is that it follows that asking about existence without specifying the domain in which sth exists is meaningless.
You can say that the number 42 exists in the domain of integers. You cannot say whether the number 42 exists in general. It wouldn't mean anything.
Similarly you can say that Harrison Ford exists in our universe but Han Solo doesn't. But you cannot say whether one or the other exist in general.
Should have said "physical" not "real" probably. I didn't meant to imply it's more "real" than the integers or any other domain, my point was that you have to specify the domain and that there are many options.
It seems to take a highly reductionist pathway: reality/experience can be simulated -> simulation is computation -> computation is mathematics -> mathematical objects exist regardless of whether anybody has discovered them.
This implies that all conceivable universes (including the ones where a lot of really bad things happen on an eternal loop) are possessed of the exact same reality as ours.
Am I missing something here? I can suppose a universe where the premise is false (This is a conceivable universe, I’d argue). Doesn’t that mean that this premise really is false?
I believe so, yes. I think it's somewhat likely that mathematically minded people would come up with that idea independently -- it's essentially Platonism taken to its logical conclusion.
You might also like to check out Greg Egan's Permutation City[0] which (in the form of entertaining scifi) presents some related arguments about the need for a computational substrate, or lack thereof.
Take a smaller example: weather on Earth. There are a LOT of particles, but still classically simulatable. Chaos ensures that we still cannot know all future states of the weather. This is a remarkable truth, and one should give it time to sink in.
Note that quantum modelling those effects go as O(a^N). If you want to hand-wave away exponential computational cost, then I cry foul: the details matter, and I posit that you cannot build a computer that is more powerful than the universe itself.
Sure, but this argument is for simulation theory... not what is described here.
What I'm suggesting is that the calculation never needs to be done, which means the complexity of it does not matter. Whether it's O(1) or O(a^N) they're both far smaller than the infinite number of potential states.
Well, that's your preference then. But personally I want to see the Mets play the Yankees because it's profoundly unsatisfying to believe that all possible outcomes are computable and therefore on an equal basis. I daresay that idea is so bad that if you took it seriously, it would die out with your genes/memes. (Not that that matters since you could travel to and impregnate every woman on Earth).
I think the author's premise would lead to the conclusions that you really are hungry and you really eat the pizza, but the former is not causal in the latter (they are just theorems of the formalism) and the latter is not causal in anything else.
Readit News
https://en.wikipedia.org/wiki/Modal_realism
There isn't really much of a connection between this and Bostrom's simulation argument. The simulation argument is about calculating the probability that we live in a simulated universe based on certain assumptions about human behavior and technological development. Bostrom's argument doesn't make any metaphysical claims other than assuming that consciousness is substrate independent.
I don't buy into metaphysical theories that claim to deduce the existence of worlds outside our own based on armchair reasoning. We know that the physical universe exists and we can explain everything that we experience in terms of quantum field theory and general relativity. Any theory that wants to challenge this view of the world needs to modify those existing theories, or design an experiment that shows why they aren't adequate to explain reality.
https://philpapers.org/archive/SINPG
It's a fun read
Dark matter would like a word.
Of course, there is always the possibility that another revolution in physics happens, but even then our current theories will still be valid in most domains, in the same way that Newtonian mechanics is still valid in most domains.
Everything we experience, except experience itself. Conscious/qualia/whatever is still… well, none but God knows what it is, and I have no evidence for the existence of any god let alone that one.
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The number states do not magically appear in the physical universe merely by thinking up the construction. The numbers could be configured as (temporary) patterns in physical objects, such as brains, books, or in ink molecules on paper. But the states are not physical objects themselves.
Also, if our universe happens to be universal, in the sense that it encompasses all of existence, then how could a calculation device exist outside of it? I'm not saying this is necessarily the case, but it's an option that many simulation-believers overlook. The calculation device might be part of the existence, but it seems rather unlikely that it can then predict reality faster than it unfolds.
Think of it this way. Graham's number is an absolutely enormous number, right? Let's assume for the sake of argument that nobody has ever computed the Graham's-number-th digit of pi. We know for certain that there is a Graham's-number-th digit of pi. And we know that if two people calculated it independently, they'd get the same digit. But (at least in this hypothetical) nobody has actually ever done the calculation to see what the Graham's-number-th digit of pi is. Given all I've said so far, the act of finding out the Graham's-number-th digit of pi seems more like an act of discovery of something that already existed than an act of invention of something that didn't already exist. So, it seems quite reasonable to many to conclude that numbers "exist."
Also, Iah's view does imply that our universe does not encompass all of existence. It also implies that no calculation device need exist anywhere.
... but that's different to what I've argued here. I'm not claiming the states are physical objects, but just the existing of the pattern, even if temporary or intangible, would feel real to the humans/actors inside it.
If you are trying to prove the existence of this universe by requiring the existence of another universe, then it's turtles all the way down.
How do you define "existing" of a pattern? Does it exist inside a physical thing? If so, then how does that physical container come into existence? And if it exists only conceptually, then how is it possible for concepts to exist? In the universe that I know, concepts only exist in the minds of human beings, and perhaps in some other animals. To me, it seems rather unlikely (and a bit anthropocentric or egocentric) that concepts are something truly universal.
For me, it helped to meditate a lot on what it'd be like to be a rock. The rock does not have memory, no sensory input, and therefore most likely no concept of time, space, logic, nor mathematics. It makes you wonder whether the rock exists at all. In any case, it probably doesn't care as much about it as we humans do. There might be a hint there.
Hmm... calculation device? I thought the premise here is that actually doing the calculation is not necessary - a tenet you invoke in order to say say elsewhere [1] that the computational complexity does not matter, as the notionally simulated universe exists anyway.
But if that were so, would it not do away with the distinction between simulating and simulated universes, creating the situation where every possible universe exists in every extant universe?
That's a lot of universes.
[1] https://news.ycombinator.com/item?id=37449804
On another hand the opposite (requiring a mapping from that computation to real-world objects) is absurd too, because for any sequence of numbers you can always find a mapping to physical objects (notice that you can make the mapping arbitrarily complex). So why require the extra steps?
My opinion is that it follows that asking about existence without specifying the domain in which sth exists is meaningless.
You can say that the number 42 exists in the domain of integers. You cannot say whether the number 42 exists in general. It wouldn't mean anything.
Similarly you can say that Harrison Ford exists in our universe but Han Solo doesn't. But you cannot say whether one or the other exist in general.
It seems to take a highly reductionist pathway: reality/experience can be simulated -> simulation is computation -> computation is mathematics -> mathematical objects exist regardless of whether anybody has discovered them.
This implies that all conceivable universes (including the ones where a lot of really bad things happen on an eternal loop) are possessed of the exact same reality as ours.
For reference: https://en.wikipedia.org/wiki/Mathematical_universe_hypothes...
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I hadn't heard of it before, and will need to do some more reading, but at a high-level it does look to be the same line of thinking.
0: https://en.wikipedia.org/wiki/Permutation_City
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Note that quantum modelling those effects go as O(a^N). If you want to hand-wave away exponential computational cost, then I cry foul: the details matter, and I posit that you cannot build a computer that is more powerful than the universe itself.
What I'm suggesting is that the calculation never needs to be done, which means the complexity of it does not matter. Whether it's O(1) or O(a^N) they're both far smaller than the infinite number of potential states.
Well, that's your preference then. But personally I want to see the Mets play the Yankees because it's profoundly unsatisfying to believe that all possible outcomes are computable and therefore on an equal basis. I daresay that idea is so bad that if you took it seriously, it would die out with your genes/memes. (Not that that matters since you could travel to and impregnate every woman on Earth).