Given a non-relational definition of ‘exist’, it doesn’t seem absurd at all to me since an absolute definition of the word seems to be a mere mental construct without any metaphysical distinction. I mean, imagine two identical universes, except one exists and the other doesn’t. What test could an observer in that universe perform to determine which one he was in? Yes, the question presumes a denial of the principle that existence precedes predication. A unicorn is horny. That’s predication without supposed existence, so I ignore the principle.
Did a whole topic on this if you’re interested.
That kind of follows. Objective existence is typically hereditary. If X relates to Y (like we do to our universe), then both presumably share the same objective ontology. But so what? There not being a test for non-relational existence, my lack of it would be undetectable.
As you might tell, I abandoned realism some time back since it creats far more problems than it solves.
Well, we’re trying to leverage weak anthropic principle here, so only some of the multiverse types help with that.
Quilted: Kind of like Tegmark type I: The universe is infinite, so if there’s one of you, there’s infinitely many more, separated by some computable average distance. This doesn’t much help the anthropic thing.
Inflationary and Landscape: Combined, this is Tegmark type II
Inflationary posits multiple bubbles where inflation epoch ceased. Landscape suggests that each of these bubble universes might have different settings of the constants, which is critical to anthropic reasoning that seeks to explain observation of optimal settings. But it’s still all the same QM rules, and neither inflationary nor landscape helps explain that.
Landscape
Brane: From string theory
Cyclic: Doesn’t help since presumably the same rules happen over and over.
Quantum: MWI: Doesn’t help. This is Tegmark type III
Holographic: I fail to see how this is a multiverse
Simulation: This is by design, so doesn’t count. It’s the same as positing a god.
Ultimate: Tegmark type IV: all other mathematical structures, notably anything where QM doesn’t apply. This must also be taken into account to ground anthropic reasoning.
Yes, that’s the whole point. If they ‘exist’ as you put it, then there’s probably a lot (oodles of orders of magnitude) more of them than there are observers in interesting ordered universes like the one we believe ourselves to be part of. So the odds of our beliefs being correct become zero.
Per Carroll, “the theories that predict [such consciousnesses] are cognitively unstable: they cannot simultaneously be true and justifiably believed.”
MUH, without modifications, is a theory that makes such predictions.
Tegmark seems to simply deny that MUH predicts them, but without justifying the assertion. Maybe it’s justified somewhere. My search didn’t get that far.
That was using a relational definition of ‘exists’, ‘to be containted by X’, kind of like I exist in this universe. A universe not contained by something not part of it lacks this kind of relation, and hence does not meaningfully exist in that sense. Of course there’s several alternate definitions of ‘exist’ that one can choose, many of which are still relations.
For instance, many believe that the universe ‘started’, that it didn’t exist, and then at some point came into being. That’s a suggestion of it being contained (by time), and so that usage is consistent with the ‘contained by’ definition of ‘exists’. Of course that naive view was pretty much demolished over a century ago. Time is part of the universe, probably not the other way around.