So, when explaining the universe we imagine it's an act of will by a conscious entity (ie., like how we invent). When explaining the mind we suppose it's like one of our inventions.

Absent an analogy of some kind it's quite hard to determine what features are salient. Objects have an essentially infinite number of properties.

Unless I’m misunderstand you, that line of reasoning assumes one is religious.

Maybe one could argue that too requires adherence to some religious dogma (Scientism? Reductionism?)

Was it? What evidence do you have for that? If anything it sounds like the kind of verbal slapdown someone in authority would subject someone trying to be a smart alec. It is short. Easy to understand. And closes the kind of questioning.

I would be very surprised if someone have considered it the literal truth, but of course have seen stranger things.

> heavenly clockwork and computer program perspectives are clear metaphors.

I don’t know about the clockwork. You will need to find someone who talks about that and ask them if they meant as a metaphor or not.

On the other hand I know about the computer simulation one. That for me is not a metaphor. I seriously think that it is within the realm of possibilities that this universe we live in (including us) is a literal simulation.

There would be possible physical experiments which depending on their results could make me increase or decrease my confidence in that statement. But I don’t consider it a metaphor.

Now of course that is only the viewpoint of a single human, at a single point of time. So it might not matter much. But it shows that it is not that “clear” that everyone considers that view only as a metaphor.

Notice how you dropped the “computer” part. Without that qualifier, the “universe is a simulation” hypothesis goes back at least to Descartes and his evil demon [1].

That’s the GP’s point. The “demon,” “clockwork,” and “computer” are just metaphors to help illustrate the point. Hundreds of years ago it was a trickster demon, now it’s computers - the simulation part is the same.

(The world floating on a turtle idea traces to the world turtle and several different creation myths, so it’s safe to say their believers took them a bit more literally)

[1] https://en.m.wikipedia.org/wiki/Evil_demon

I don't think so. I do understand this lineage of thought, and I agree with you that they are somewhat similar. But I must insist in saying that what I'm talking about is different.

The trickster demon metaphor talks about a being (you) whose senses are replaced by the demon. But that means there is a you outside of the demon/computer simulation.

I believe if this universe is a simulation, then I am part of that simulation. My mind is not an external observer hooked up to the simulation, but just matter simulated by the simulation according to the rules of the simulation. The thing Descartes was talking about is a Matrix situation. (Or rather to say the creators of Matrix were paraphrasing Descartes) Neo thinks he is living his life, but in truth his body is laying in a pod in the goo. I don't believe in that. I don't think that is likely true. If this is a simulation then me (and you, and this computer, and all of the people, and the butterflies and the stars) are in the simulation. And not the way how Neo is in there, but the way a cubic meter of minecraft sand is inside a minecraft world. Inside the minecraft world it is a cubic meter of sand, outside of it is just a few bytes in the memory of some program.

Let me illustrate what I mean when I say that I don't speak about the universe being a computer simulation as a metaphor. Imagine that it is a simulation. What does this computer simulation have to do? Well, it seems that there are particles, and there are forces between them (gravity, electric, weak/strong nuclear force) In every iteration of this simulation it would seem that you need to calculate which particles are close to others so you can update the forces on them, so you can calculate their new state.

To do this you need to inspect the distance between every two particle. That scales with ordo N^2 with the number of particles N. If the universe is a computer simulation it probably runs on a computer of immense power. But even then N^2 scaling is not good news in a hot path. Funny thing is that if the universe you want to simulate is relatively sparse (as is ours), and has an absolute speed limit (as ours seems to have), then you can shard your workload into parallel processes. And then you can run the separate shards relatively independently, and you only need to pass information from one shard to an other periodically.

Now if our universe is a simulation, and it is sharded this way, then you would expect anomalies to crop up on the shard boundaries. Where the simulated mater is moved from one executor "node" to an other. We could construct small spacecraft and send them far away (perhaps other solar systems?). We would furnish these small automated spacecraft with sensitive experiments. Microscopic versions of a Newton's cradle, or some sort of subatomic oscillator, or a very precisely measured interferometric experiment. And the craft would autonomously check constantly that the laws of physics are unchanged, and work without glitches.

If we don't see any glitches, then we shrug. Either we don't live in a computer simulation, or the computer simulation is not sharded this way, or the edge cases are very well handled, or the instruments were not sensitive enough, or the shards are even bigger (perhaps we should have sent the same experiments to a different galaxy?) If we see glitching, then we should try to map out exactly where they happen, and how they happen, and that would be very interesting. And if we see glitching of this kind that would increase my confidence in us living in a computer simulation.

Does this make sense? You cannot design an experiment to test a metaphor. It doesn't even make sense. But I think of this as a possible literal truth, in which case you can formulate hypothesises based on it and you can check those with experiments.

> so it’s safe to say their believers took them a bit more literally

I believe you. Did anyone ever propose to solve a famine by sending a hunting party to cut a chunk of the turtle's flesh? Or to send gatherer's to collect the dung of the turtle to fertilise the land? Or to send holly people to the edge of the world, to peer down at the turtle to predict earthquakes? If the turtles are meant to be literal turtles these are all straightforward consequences. If nobody ever proposed anything like these, then perhaps the turtles were more of a metaphor?

That is different from "we're living in a computational medium", which doesn't claim it's simulating something else, and is the only level of existence. (i.e. Fredkin et al)

> You still have to explain THAT.

I see your point there. Sadly the universe is not obliged to be easy to understood. “If X then I have further questions, therefore not X.” Is not a logical reasoning I recognise.

What I am saying is that you can’t argue that we are not in a computer because that would bring up a host of questions.

> That is different from "we're living in a computational medium" which doesn't claim it's simulating something else

Interesting. The way I use these they are synonymous in my mind. I don’t claim that there is something else out there which the simulation mimics. If you have some state representation and some rules to describe how the state propagates then I would describe a computer program which calculates new states based on the old one a simulator. This is the sense how I use the word when I say “we might be living in a simulation”. If this bothers you feel free to just imagine that I am saying “we might be living in a computational medium”.

> and is the only level of existence

Now, why exactly do you belive that? Why not 2 levels? Or 3? Why do you feel believing that there is only one level of existence is more justified than those other arbitrary numbers?

But it’s even worse than it sounds at first, because you need to spend energy not just on calculating the interactions which is super linear with the number of objects, you must also spend the energy to make it possible for the objects to interact in the first place.

Almost feels like it's related to P=NP or logic and meta-logic. Is it fundamentally impossible to use the same 'Universe'-al representation inside the Universe, a Gödel-like result limiting us only to the real? Or can we represent and run subsets of smaller universes within without a computational explosion? If so, does it eventually revert back to becoming fundamentally impossible at some limit, and if so, are we there yet? Can we measure how far from the limit we are, somehow?

Fun questions. Thanks for the provocative clarification.

Calculation may be the wrong word for what’s necessary for a simulation, but I don’t think you can have a simulation without something analogous to computing. But the computation may look foreign, think analog vs digital computers. I mean, what would it mean to simulate something if you weren’t interested in finding some measurable thing? How do you seperate the ability to observe the simulation and not be able to measure anything? I may be too steeped in engineering to be able to answer this, since the last thing I simulated was an analog circuit. But I also studied artificial life, and even there the goal was to learn something about life.

I think about this a lot, and sometimes wonder if the edges of science can't be solved until some meta being comes along and implements that edge case. And then the edge cases get weirder and weirder. But really, I'm relying on my intuition of superlinearity when I think about this stuff, and I can see certain problems with simulations going to infinity faster than, say, the infinity of the infinite time argument that we must be in a simulation.

<https://quoteinvestigator.com/2021/08/22/turtles-down/>

The version I'd first heard attributed the story to a lecture by Bertrand Russell and an audience Q&A, though it seems clear that that couldn't have been the first instance.

I've run across the Vonnegut variant more recently. I don't recall where or when I heard the earlier version for the first time, though I suspect it came up in conversation without attribution. Likely sometime ~1980 -- 1999.

That variant may well trace to Vonnegut, though I suspect it had been passed through numerous mouths and ears by the time I heard it.

https://en.wikipedia.org/wiki/Yertle_the_Turtle_and_Other_St...

>Seuss has stated that the titular character Yertle represented Adolf Hitler, with Yertle's despotic rule of the pond and takeover of the surrounding area parallel to Hitler's regime in Germany and invasion of various parts of Europe.[3][4] Though Seuss made a point of not beginning the writing of his stories with a moral in mind, stating that "kids can see a moral coming a mile off", he was not against writing about issues; he said "there's an inherent moral in any story" and remarked that he was "subversive as hell".[5][6] "Yertle the Turtle" has variously been described as "autocratic rule overturned",[7] "a reaction against the fascism of World War II",[8] and "subversive of authoritarian rule".[9]

I see it has a history in India and China too.

https://en.m.wikipedia.org/wiki/World_Turtle