[Nevermark]

> None of the leading interpretations of quantum theory are very convincing. They ask us to believe, for example, that the world we experience is fundamentally divided from the subatomic realm it’s built from. Or that there is a wild proliferation of parallel universes, or that a mysterious process causes quantumness to spontaneously collapse.

Actually, the "many worlds" "interpretation", simply treats the highly successful equations as meaning what they say.

And it is misnamed. The field equations describe a highly interconnected "web universe" of "tangles" (what I call spans of entangled interactions) and "spangles". (My shorthand for superpositions, i.e. disjoint interactions of particles. Think of all the alternate lines leading from and two distinguishable states, like star patterns.) Basically, a graph of union and intersection relations where all combinations, individually and en masse, are determined exactly by the laws of conservation.

That's an amazingly good property for a theory. And we have it.

By including all consistent versions, no external information is required by the theory. It is informationally complete. A successful objective explanation. With deep experimental support that entanglement and superposition actually exist, because their interactions are easily testable.

In fact, entanglement doesn't "violate" locality, it is the more general case which explains locality. Locality is just tightly coupled entanglement/interaction. Not a fundamental constraint on connections. There is no fundamental "distance", just loose and dense connections. Locality is just what we see wherever there are patterns of dense connections. They are an effect, not a constraint.

Even in the classical world of large (highly tangled) objects, we take it for granted that dependent objects can separate over arbitrarily vast dimensions of space and time and yet return together. If that isn't entanglement over vast distances, what is it? It is a basic property of classical physics. Quantum mechanics reveals more subtlety in those maintained connections, including interactions between connections, but it didn't originate them.

Forces disappear. They become passive in an interesting way. Histories where information cancel, leave structured distribution patterns behind, which to us look like forces. Cancellation is just information being conserved. Not an active force. But the results appear active.

In a similar way to how the evolutionary umbrella seems very smart and creative, when really, it is just poorly adapted individual creatures independently cancelling themselves out blindly, leaving a distributional improvement behind.

There is no additional information needed to explain the effect of quantum "collapse" because it is already explained by the fast bifurcation of disjoint tangles when lots of particles interact in an unorganized manner. It is thermodynamics being thermodynamics.

Anyone attempting to invent a mechanism for "collapse" is like someone trying to explain why the spherical Earth appears "flat" by introducing additional speculative theories. Despite the spherical world theory already explaining why it looks flat locally.

And the only reason to not take the experimentally verified field equations as a plain reading, is the result is "too big" for someone's imagination.

Our everyday experience doesn't limit reality, despite humans having trouble with theories that reveal a bigger reality, over and over and over.

Bluntly: The total field equations preserve information - that is the plain implication and guarantee for having both unions (tangles) and intersections (spangles) of interactions.

Anything else requires a universal firehose of magically appearing information to choose collapses, i.e. particular interactions, in order to explain something already explained. In other words, dressed up voodoo. And by "re-complicating", uh, "re-explaining" the already explained, introduces a ridiculous new puzzle: Where does all that pervasively intrusive relentless injection of information (that determines every single extricable particle interaction!), come from? (Occam is spinning like a particle accelerator in his grave.)

Saying it "Just Happens" is like someone "explaining" their pet version of a creator with "Just Is". It is a psychological non-taulogy for "Don't Ask Questions".

[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.

[Nevermark]

Good questions.

> The future me would end up in one of two branches: I measure spin up, or I measure spin down.

The future "you's" would each see spin up, and spin down, respectively.

We are just as quantum as what we measure. There isn't a scale where entanglement and superposition turn into something else. No classical vs. quantum atoms.

Just as an up-spin qubit touching an up/down qubit results in an up-up qubit pair in superposition with an up-down superposition, conserving the qubit, when we touch a qubit we get "us"-up and "us"-down versions.

No information is created. None is destroyed. We experience a correlation = "collapse" (both versions of us), but the quantum information just continues on as before, qubit conserved.

[qsera]

>But somehow “I” only experience only one of them.

Using the example from the other comment, "You" are the stream and not a drop of water in it.

In other words, you are not an entity with unique identity that traverse the tree of possibilities. You are part of the tree, actually, part of a branch. The branch's existence and your existence implies each other. Like your hand's existence and your existence imply each other. Your hand could not have existed without you (a similar looking one could. but it wouldn't be yours). And you without your hand (you could have had a different hand, but that wouldn't be "you" (which also includes the hand))

[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]

> It's what having such senses feels like from the inside; the first-person view.

The hard problem is that there is such a feeling at all.

[A_D_E_P_T]

It's not hard at all when you acknowledge that such senses exist in the world, and that you (like others) possess them. As an aside it tends to foster a certain tendency towards empathy.

In essence, you're asking why there's an inside to being a self-modeling system. But "inside" isn't something extraneous, something additional -- rather, it's what "self-modeling" means.

Really the "hard problem" has a very easy answer, but it's a physical/functional answer, and dualists and obscurantists simply don't like it.

[fnordlord]

It's embarrassingly silly to say but I've frequently just boiled down the hard question to the question of "where is the experience of the color blue stored in the universe?" Even as a non-dualist, I still haven't found much of an answer that I like. I'm all ears if you've got a book recommendation.

[Sharlin]

So you say that the hard problem of consciousness is explained by the fact that we appear to be conscious?

[prmph]

How do you know they (and others) possess them?

[uh_uh]

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

[Nevermark]

We have a theory whose plain reading matches experiment at all scales.

Consciousness is something else. It is tempting for humans to pair mysteries up, pyramids and aliens, or whatever. But there isn't any factual basis for linking the experience of self-awareness with quantum mechanics.

Is there a factual reason we know digital minds couldn't be conscious? Where quantum effects have been isolated from the operations of mental activity. That seems like a premature constraint to assume.

[uh_uh]

I wasn't trying to link the two. Just pointed out that there seems to be a lot of unknowns on the map.

[borissk]

I think you're right, the many worlds interpretation makes the most sense. Unfortunately out current technology is very far from delivering any experimental confirmation or denial of any of the mainstream interpretations.

[Nevermark]

You are right, but I think there is a more positive viewpoint.

All experiments agree with the many worlds interpretation (again, better described as a quantum web interpretation), and it is the plain Occam's Razor interpretation.

No additional flourishes are needed. That is strong theoretical support. It is the default (plain reading) interpretation already.

And it is the interpretation that doesn't just conserve in one history (i.e. conservation of energy etc.), but conserves information universally.

So again, very strong specific theoretical support.

It is the conjectures about experimentally unmotivated elaborations, like "collapses", that would also break universal conservation of information, for no theoretically necessary reason, that need dramatic new evidence to prove themselves.

If I lack any optimism, it is for conjectured complications with no evidentiary support and weaker explanatory/conservation powers. In any other context, nobody would be entertaining the need for such conjectures.

The "Quantum Collapsers" are right up their with the "Flat Earthers", or solar system "Epicycle Theorists", for not being happy with accepting a working and successful theory as is. Even though their imagined shivs introduce more questions than they answer, and would dispense with its unique advantages.

[spot5010]

What if we create a situation in a lab that can be labelled as a collapse of the wave function by interaction with a macroscopic object. Except the macroscopic object is under our control and we can reverse the collapse.

A quantum computer is such a macroscopic state.

[borissk]

From the decoherence / Many-Worlds view: No collapse occurred. Only entanglement happened.

[prmph]

I think the MWI is actually the just-so explanation you claim to avoid.

Is it falsifiable?

If you have a theory that seems unassailable by any logic, that's a good signal it is tautological and not very useful.

[superposeur]

Yes, the MWI is falsifiable. It asserts that objective collapse does not occur, therefore any observation of objective collapse (such as predicted by GRW or Penrose-Diosi) would falsify it.

[prmph]

That's not true falsifiability; its asserting a negative.

I think people resort to MWI because they think it explains everything neatly; it does not!

For example, from my perspective, it does not explain what world I end up in, and if you are saying it's random, you need to come with a fundamental theory of randomness, unless the response is: it just exists, deal with it.

[Nevermark]

Negatives can be falsified.

“There are no black swans.“

A negative, that can be falsified by a single black swan.

You are mixing up another kind of argument. Claiming there are elephants in the room we cannot see or touch is an example of an unfalsifiable claim.

In fact, claiming there is a quantum collapse, which always looks just like the field equations without a quantum collapse, would make collapse an unfalsifiable theory.

(I don’t believe most proponents of collapse are making that claim.)

[superposeur]

If this experiment: https://ui.adsabs.harvard.edu/abs/2024arXiv240202618T/abstra... or others like it turn up positive results, MWI is falsified.

[uh_uh]

Isn't there a magical moment needed still when a single qubit "touches" the rest of the universe?

[Nevermark]

It touches you, and you are just as quantum as the bit.

So two entangled versions of you follow, one entangled with each state. (Actually as many quantum versions of you that touched the qubit times two.)

Which is what happens, as we know from experiment when any one qubit interacts with another independent qubit. We get the product of entangled states, each now correlated. But different entangles states are now in superpostion with each other.

So correlation/entanglement happens and is experienced, despite no collapse of superposition. No information was destroyed or created.

Each of you thinks, wow now the qubit only has one state. But that is because there are two versions of you, correlated respectively with the two uncollapsed qubit states.

Complete conservation. That is the "experience" of collapse that needs no explanation, because it is a predicted experience not requiring an actual collapse. Just as spherical Earth models don't need a special explanation for the appearance of locally flat Earth, because spherical models predict a local flat Earth experience.