[spot5010]

The part that I have trouble wrapping around with many worlds interpretation is how I as an observer end up in one of the many bifurcations. Any links you can share that will help me with understanding that is welcome!

The Stanford Encyclopedia of Philosophy (https://plato.stanford.edu/entries/qm-manyworlds/) goes into this in some depth, and it seems like the right way to think about it is say that "I" in one branch is a different entity than the "I" in a different branch. I have somehow not been able to grok it yet.

And I agree about the naming. I really dislike the name "many worlds interpretation", which seems to imply that we have to postulate the existence of these additional worlds, whereas in fact they are branches of the wavefunction exactly predicted by standard quantum mechanics.

[Nevermark]

> The part that I have trouble wrapping around with many worlds interpretation is how I as an observer end up in one of the many bifurcations.

Pour water down a hill. Water clings to water, and we have hills that already have lots of correlations. We get streams that break up into multiple streams.

How did one stream end up where it is? It seems like a good question, but it is circular. The stream is defined by where it is. You are here (in some circumstance), because the version of you in this circumstance is you.

A transporter accident that creates several versions of you, on several planets with difference colors, doesn't need to explain to each version how they ended up at a planet with their color. Even if for a particular copy, it seems like there should be an answer why they showed up on a planet of a particular specific color. The "why" is just, all paths were taken.

[spot5010]

What you said here makes sense. Forgive me, but I have trouble even articulating what it is that I don’t understand correctly.

Maybe what I meant was this: if I perform a quantum experiment where the spin measurement of an electron could be spin up or spin down, the future me would end up in one of two branches: I measure spin up, or I measure spin down. There wouldn’t be any possible world where I measure a superposition of spin up and spin down, because such a a state is going to decohere rapidly. This makes sense. What I’m unable to grasp is that even though the wave function of the universe contains both branches, “I” somehow experience only one of the two branches.

The answer to that I guess if that the two branches are nearly orthogonal they will merrily evolve independent of each other. But somehow “I” only experience only one of them.

Sorry for the rambling. I’m not able to articulate what I don’t understand.

[TheOtherHobbes]

The problem with Many Worlds is that it doesn't place a bound on the number of worlds, so you can't derive the Born Rule from it.

That's quite a serious issues. And arguments against that - like Self-Locating Uncertainty, or Zurek's Envariance - look suspiciously circular if you pull them apart.

There's also the issue that if you don't have a mechanism that constrains probability, you can't say anything about the common mechanism of any of the worlds you're in. Your world may be some kind of lottery-winning statistical freak world which happens to have very unusual properties, and generalising from them is absolutely misleading.

There's no way of testing that, so you end up with something unfalsifiable.

[spot5010]

There’s papers that “derive” Born’s rule from the many worlds interpretations, e.g. https://arxiv.org/abs/1405.7907

I don’t claim to understand them though. I have tried.

[Nevermark]

> The problem with Many Worlds is that it doesn't place a bound on the number of worlds, so you can't derive the Born Rule from it.

I have no idea what this means.

Is there a bound on anything in reality, in terms of scale? Beyond its own laws?

I am reminded of how often in history, too much time, or too much scale, were unsuccessful arguments against many theories we accept today. Those critiques died without any need for special arguments, because they don't have a logical basis.

Also, there are not a number of many "worlds". That is a reflection of poor naming. There is an interleaving of all interactions, so if you zoom out, a smeared landscape across all configurations, from the plank scale up.

Because the connections involve both intersection (entanglement) and union (alternate paths), we get bifurcation of classical sized paths (dense entanglements), while the individual particles continue unconcerned by how they appear to create different classical histories at large scale.

And yes it is experimentally validated. This is the theory that everyone accepts in the lab, even as larger scales of experiment continue to progress.

But some people have difficulty believing/visualizing that it continues to work at larger scales. Despite no scale limitation in the theory, no scale related violations ever suggested experimentally, and the strong likely that scale limitations would produce new physics in at-scale observations of our cosmos if they did exist.

[qsera]

> how I as an observer end up in one of the many bifurcations..

Just a pleb here, but that does not stop me from thinking about it..

I think your consciousness is a function of the world you belong. So asking why your are in a certain world, and not in other, is like asking why you are born to your specific parents, and not to others.

So you don't end up in some fork, by a roll of dice, you are already confined to, and defined by a single branch.

So I don't think the exact "you" don't exist in another branch. But another consciousness that only differ from "you" by only a single random event (ie you and this consciousness only differ from you in the observation of a single random event) exist in another branch.

And it is not like this is all orchestrated by some entity. It is just how consciousness and subjective experiences emerges in mathematical structures (+ the set of random events), that does not need rendering anywhere (Mathematical Universe Hypothesis).

Once you understand the hopeless inevitablity of existence, a lot of questions like "When", "how", or "why" of our existence disappears.

You can ask if there is any proof for this, except for some thought experiment. But I think the only thing that can come close to proving this is if we exhaustively searched for other extra terrestrial consciousness and don't find any.

[Sharlin]

Everybody is utterly confused by the hard problem of consciousness. That's just how it is.

[A_D_E_P_T]

"Hard problem" makes it out to be much more difficult than it actually is. To simplify things a little bit, if you combine a spatiotemporal sense (a sense of bounded being in space and time) with a general predictive ability (the ability to freely extrapolate in time and space from one's surroundings,) "consciousness" arises necessarily. It's what having such senses feels like from the inside; the first-person view. It's a matter of degree, of course.

The writing of Chalmers and its consequences have been a catastrophe for philosophy.

[uh_uh]

I'd say we are confused about both the lowest (quantum) and highest level (consciousness) phenomena of the known Universe. Quite humbling.