The multiverse hypothesis (in the style of Tegmark, et al) is partially motivated to render this sort question invalid. You're asking, effectively, "what are the hidden variables behind the multiverse", whereas the idea specifically asserts that there aren't any.

The idea is that what underlies each possible universe is just math, "all the way down".

So the question you're asking is exactly like, who created the sinusoid curve, pi, or prime numbers.

Proving the idea may be impossible. That doesn't make it wrong. If some aspect of reality is not provable, then that can't be helped.

The fascinating thing is that the hypothesis cannot be disproven either. The hypothesis that there is only one universe also isn't provable; the fact that other universes haven't been discovered/accessed doesn't prove it, since lack of evidence of existence isn't a proof of nonexistence.

The hypothesis that there are multiple universes is simpler than the hypothesis that there is just the one. It's more believable, and explains more. For instance, all remarkable coincidences in the structure of our universe are explained via the anthropic principle, which is greatly boosted by the multiple universe hypothesis.

But, if I'm not mistaken, the multiverse hypothesized by Hawkin, and the usual multiverse from String theory is not this mathematical multiverse. In String theory multiverses, not every possible universe is allowed to exist, only universes satisfying string theory conditions. That's not to say those hypothesis are inconsistent -- the String thoery multiverse may exist within the "Mathematical multiverse". Once we accept that falsifiability isn't the only motivation to create theories (say by subscribing to MUH), then we need to accept that maybe our universe is also part of a larger non-observable universe, if and only if this provides a particularly "simple" explanation to our existence.

I don't see how the essentially magical appearance of an incredibly complex set of axioms from nothing at all is a plausible answer to the 'Why something instead of nothing?" question.

To be clear, I have absolutely no idea how to answer that question. I'm certainly not a closet theist. My best guess is that a useful answer is currently some way beyond our pay grade as a species.

So I don't find "Because math" to be any more convincing as an answer than suggesting god did it.

> any more convincing as an answer than suggesting god did it.

Doesn't have the problem of 1) asserting that no other gods exist other than this specific god or group of gods and 2) the issue of who created god.

We don't ask, who put pi about 14% of the way between 3 and 4; that's almost silly.

:)

It would make sense to me that reality, encapsulating all that exists, "is" because "it must be", like Math.

You presume it was created. It might be as valid a question as "who created erosion", aka math is a natural extension of our universe.

Or, more likely IMO, our universe is a natural extension of math.

I get it, but I can't quite wrap my head around a mathematical universe with no substrate. As though any internally consistent ontology with self-aware structures (and, it seems to me, also those without) just "exists" apropos of nothing. What's doing the math?

It's proving it's nonexistence that is quite a challenge. Proving their existence could be demonstrated by, for instance, traveling to them. I personally see no reason to believe that is possible, but if somebody traveled to one and thereby disproved me, that would be that.

That said, it might just about take that to prove one. Even if one produces theories that say a multiverse might be possible, I expect there will always be a simple transform for which the equations still work but there is only the one universe. For instance, taking well-established existing equations, while the QM field equations may imply that a quantum multiverse is possible, no matter how mathematically distasteful some people may find it the Copenhagen interpretation is still possibly the truth, and I'm not sure what possible experiment could disprove that. (The Universe may do as it damn well pleases.) I'm unsure what evidence we could collect other than concrete proof of existence that would somehow prove multiverses.

> I have pointed out several times in the preceding sections that the C.I. and the Everett “interpretations” are really different formalisms for quantum theory—in effect, different physical theories. It is usually claimed that although their assertions as to the nature of objective facts are radically different, the two “interpretations” agree about all subjective experiences of observers, and cannot therefore be distinguished experimentally. That this claim is false is shown by equations (40) and (42) which summarize the different predictions of the two “interpretations” concerning further measurements on subsystems one of which has completed a measurement on the other.

https://pdfs.semanticscholar.org/c948/44bc9128e77077abdf36a6...

The premise of proving nonexistence is the wrong way to assess credence of a theory.

Likewise, proving existence of multiverse is as impossible as proving nonexistence for the reason that the multiverse is postulated as existing independently in an infinite number of permutations that can not interact with each other. If multiverse permutations can exist in the same time and space as another permutation, then matter and energy are supposed to exist in infinite number of states simultaneously, and would be impossible to measure.

On the nature of God, I read a theory that God is "truth", and thus any being that comprehends all truth is essentially God. In our human quest to gain knowledge of the truth of the universe, we have developed the ability to accomplish things that hundreds and thousands of years ago would have been considered God-like.

In 13.7 billion years of the existence of the universe, is it not possible that some entity was able to obtain sufficient knowledge of the truth of reality (laws of nature) to be indistinguishable from "God"?

That person would have to travel back as well, thereby making this proof doubly hard :-)

Humans can not directly observe an alternative permutation, but even if they could, how would they be able to find their way back to their original permutation if there's an infinite number of permutations?

The multiverse need not have different physical laws; the quantum multiverse if true, for example, is basically our universe just viewed from a different point of view.

"Humans can not directly observe an alternative permutation, but even if they could, how would they be able to find their way back to their original permutation if there's an infinite number of permutations?"

Unsurprisingly, science fiction authors have pondered this for a while, and one popular answer is a travel machine where part of it still stays in the universe of origin, so returning home is like pulling a rope back in. Even if we're in a quantum multiverse where the source universe and the destination universe are continuing to fuzz, you can still imagine there's some sort of correspondance that means that any given individual will still have a uniquely-corresponded universe to travel home to.

I believe this is all technobabble bunk since I doubt it can correspond to any possible real configuration of atoms and energy, but, like I said, someone could well prove me wrong by building one, and that would be that.

Maybe you could go in an alternative universe that is different, but not different enough that it prevents you to function.

In an infinite universe, there should be constant evidence of multiverse apparent.

That's the problem with the infinite universes theory. You can pretty much make up whatever you want, it answers to any question.

I remember reading somewhere an argument that universes could interact in a fashion not unlike bubbles in foam and perhaps we can measure the amount by which our particular universe is being "squished" by the surrounding universes.

But on another note, I would like to call Kant to the debate. Kant argued that humanity will never arrive at any useful understanding of universal origin (or even microscopic/macroscopic limits) because it is beyond our mental tools of comprehension. Science does attempt to bridge that gap, however how much can it help if our initial assertions require using subjective reason?

https://en.wikipedia.org/wiki/Kant%27s_antinomies

Do matter and energy simply exist without creation?

It depends on your definition of "creator" but indeed it is almost a logical necessity for something to exist without a creator. Since if you assume a creator is necessary, you'd still need someone to create the creator, and so on going infinitely. And then there's the question of creation of this infinite chain itself, etc -- the recursion never ends. It seems much more simple to assume some system must simply exist without necessity of creation.

You are spot on. This system must exist in-itself. That is, it must be so simple that its existence cannot be separated from its nature (to use Aristotelean terms). In other words, I AM WHO AM.

To get concrete, if our universe happens to be finite (which I suspect is true), a lot of mathematics doesn't describe anything that exists within this universe.