So you might have an evil twin out there in the Multiverse...

[Sci-2]

World next door: Nine theories of the multiverse promise everything and more. But if reality is so vast and varied, where do we fit in?

....But you probably won’t know that (if their findings are taken to their logical conclusion) these machines have also detected hints that Elvis lives, or that out there, among the flaming stars and planets, are unicorns, actual unicorns with horns on their noses. There’s even weirder stuff, too: devils and demons; gods and nymphs; places where Hitler won the Second World War, or where there was no war at all. Places where the most outlandish fantasies come true. A weirdiverse, if you will. Most bizarre of all, scientists are now seriously discussing the possibility that our universe is a fake, a thing of smoke and mirrors.

Though I get confused by this comment:

The ‘many worlds’ interpretation of quantum physics was first proposed in 1957 by Hugh Everett III (father of Mark Everett, frontman of the band Eels). It states that all quantum possibilities are, in fact, real. When we roll the dice of quantum mechanics, each possible result comes true in its own parallel timeline. If this sounds mad, consider its main rival: the idea that ‘reality’ results from the conscious gaze. Things only happen, quantum states only resolve themselves, because we look at them. As Einstein is said to have asked, with some sarcasm, ‘would a sidelong glance by a mouse suffice?’ Given the alternative, the prospect of innumerable branching versions of history doesn’t seem like such a terrible bullet to bite.

In light of the experiments apparently supporting the Copenhagen Interpretation.

As someone who thinks about the possibility of Mathematical Platonism, I find Tegmark's Ultimate Ensemble to rather interesting though not all that convincing:

The ultimate multiverse supercharges that idea: it says that anything that is logically possible (as defined by mathematics rather than by physical reality) is actually real. Furthermore, and this is the important bit, it says that you do not necessarily need the substrate of physical matter for this reality to become incarnate. According to Max Tegmark, professor of physics at the Massachusetts Institute of Technology, the ‘Mathematical Universe Hypothesis’ can be stated as follows: ‘all structures that exist mathematically also exist physically‘. Tegmark uses a definition of mathematical existence formulated by the late German mathematician David Hilbert: it is ‘merely the freedom from contradiction’. Hence, if it is possible, it exists. We can allow unicorns but not arbitrary, logic-defying magic.

This seems like a constrained Idealism, where the non-physical firmament is only constrained by logic?

And what would "logic-defying" magic be [given the acceptance gods/demons/devils]? And why is the author so obsessed with unicorns?

[Fez]

I prefer Futurama's vision of the multiverse: There's this universe, and then there's one other next door where everything's exactly the same, but we all wear hats.

Anything more complicated than that just gives me a headache. Also, I vaguely get the sense that all this stems from us not having a complete enough sense of math, and that one day humanity will discover some formula/equation/something that just clicks into place, explaining so much of what we don't know, and we'll look and laugh at how complicated we thought the universe was.

[IheartIheartTesla]

The multiverse isnt real.

Those who argue that this ‘isn’t science’ are on the back foot. The Large Hadron Collider could find direct evidence for aspects of string theory within the decade

Yeah ok bro.

Please read this website for a healthy dose of skepticism.

[Edda van Heefmstra Ruston]

I am the evil twin.

[Francis Buck]

The Ultimate Ensemble is pretty much the only way reality makes sense to me, though I too get confused about the non-physical Tegmark is going on about there.

ETA: I should clarify that I mean an omniverse is the only way reality makes sense to me, not specifically the Ultimate Ensemble and all its particularities.

[Castel]

I am the evil twin.

Drats!, Two minutes too late! In another universe I won!

[Ser Scot A Ellison]

IHT,

You can't perceive it therefore it cannot be real and it's a waste of time to look for it. That's my problem with materialism, right there.

Fez,

If some of the multiverse hypothesis are correct the hat universe exists.

[DaveSumm]

The multiverse isn't real.

I used to think that, but was entirely convinced by David Deutsch's The Fabric of Reality.

[Weeping Sore]

I don't think the multiverse (in terms of the near infinite multiplication of universes implied by multiple quantum states being "real" in any given moment) is real either- simply because it's not necessary under idealism. Idealism is the most elegant and "conservative" solution.

Though if it were real you'd see why every possibility would have to exist by reading Jorge Borges' The Library of Babel.

[Greywolf2375]

I can't be sure that he is evil, but I do have a gay twin. Apparently someone who lives in Hartford resembles me to the point that people I used to work with have mistaken us. Was a little awkward when I had a coworker ask me why I didn't say hi to him at the bar last night and why I hadn't come out to him before.

In front of my girlfriend at the time. Long awkward pause in that conversation.

I'd love to meet him. Apparently he has a great social life.

[IheartIheartTesla]

What testable propositions has the multiverse made? That's my problem with it. In contrast, I am ok with the QM wave function even though we cant 'perceive' it. Again, you seem to have some funny view of materialists.

Also, I can't stand these multiverse hypesters, all they want to do is be in the popular science news. I'd be skeptical of any of their grandiose claims, especially this Tegmark fellow.

IHT,

You can't perceive it therefore it cannot be real and it's a waste of time to look for it. That's my problem with materialism, right there.

[Sci-2]

I don't think the multiverse (in terms of the near infinite multiplication of universes implied by multiple quantum states being "real" in any given moment) is real either- simply because it's not necessary under idealism. Idealism is the most elegant and "conservative" solution.

Though if it were real you'd see why every possibility would have to exist by reading Jorge Borges' The Library of Babel.

Well people should read Borges regardless. :-)

When you posit Idealism as the conservative solution, is this what it means when physics articles talk about letting go of "realism"?

Like Fez my head hurts after a point and so I just try and stop thinking about it....But it's a bit unnerving to have concepts one can't even conceptualize in the mind even if the math might be unknown to me.

[IheartIheartTesla]

My evil twin would be a multiverse groupie.

[all swedes are racist]

I prefer Futurama's vision of the multiverse: There's this universe, and then there's one other next door where everything's exactly the same, but we all wear hats.

Anything more complicated than that just gives me a headache. Also, I vaguely get the sense that all this stems from us not having a complete enough sense of math, and that one day humanity will discover some formula/equation/something that just clicks into place, explaining so much of what we don't know, and we'll look and laugh at how complicated we thought the universe was.

Somewhere out there, there's a more evil version of me? I do my best, damn it!

[Ser Scot A Ellison]

IHT,

No testable propositions yet. Talk to you when it can be tested?

[jarl the climber]

My evil twin would be a multiverse groupie.

I'm somebodies evil twin in this universe :devil:

[Weeping Sore]

@Sci-

Many worlds theory is the result of trying to exorcise consciousness from quantum results. It appears that there's some kind of mind over matter at work in quantum mechanics, but dualism or idealism is a priori so unacceptable, it has to be that all results physically exist in multiple universes rather than consciousness's altering reality.

Even were we to accept multiple universes, there's still the question of why our consciousness is experiencing this universe rather than any of the functionally infinite alternatives? And is choosing among constant quantum bifurcations of the universe functionally any different than changing the course of a single universe?

[Fez]

Fez,

If some of the multiverse hypothesis are correct the hat universe exists.

Sure. But I prefer the idea that there's two universes, and only two universes. That way we can set the definable goal of conquering the multiverse, particularly since all those other guys will be too busy admiring their hats to put up much resistance.

[Rorshach]

My evil twin would be a multiverse groupie.

He would also love Edison ;)

[Ser Scot A Ellison]

Weeping Sore,

What's wrong with a priori?