[smokel]

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.

[AntiMS]

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.

[iahwrites]

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.

[smokel]

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.

[paulrudy]

[Wyslawa Szymborska's "Coversation With a Stone"](https://web.archive.org/web/20201127013535/https://www.tweet...)

And also

> Kick at the rock, Sam Johnson, break your bones: But cloudy, cloudy is the stuff of stones.

-- Richard Wilbur, from ["Epistemology"](https://web.archive.org/web/20211109141828/https://www.poetr...)

[mannykannot]

> 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?

That's a lot of universes.

[1] https://news.ycombinator.com/item?id=37449804