Re: Macroscopic Emergence in MWI worlds

On Tue, Aug 20, 2013 at 6:27 PM, hibbsa <hibbsa-/[email protected]> wrote:
>
>  ...
> >
> > > In which case are you willing to provide a plausible description for
> how
> > > quantum divergence can become part of an effect that goes on result in
> > > macroscopic divergence.
> > >
> >
> > I don't know. What is "quantum divergence"? Is it just that in some
> > worlds the photon is emitted at t_1, and at some others at t_2? It's not
> a
> > term I'm familiar with.
>
> the term wasn't correct, but we had a context and there was a key work
> divergence. I was talking about divergence in the multiverse.
>

OK -- divergence like I meant above, right?  Where a photon is emitted at
two different times in different worlds?  In that case, Schroedinger's Cat
is the canonical example of macroscopic amplification of a quantum effect.
 But so is a geiger counter, and there are many others.  Do those serve?


> > > > > So the problem is, MWI has basically has no macroscopic influence.
> > > >
> > > > That I don't understand at all. MWI just says the SWE describes
> physical
> > > > reality, all of it. Macro and micro. MWI describes it all.
> > >
> > > You say MWI says that? I thought you said yesterday that's what gets
> > > assumed going in.
> >
> > Sorry, perhaps I missed something. MWI is the theory that the SWE is a
> > description of reality, and its observables are real (they exist, not
> just
> > as "convenient mathematical fictions"). I.e. there is no collapse.
> >
> > > In which case what the multiverse says is this might be what things
> would
> > > be like, *if* it was true.
> > >
> >
> > I'm not sure how to parse that. I'm not sure the multiverse "says"
> > anything, especially anything self-referential.
>
> Gary, I was using the same style you had just used to me, you said "MWI
> says..."
>

The MWI is an interpretation of QM.  It definitely says something; it makes
definite claims (as does QM itself, as a scientific theory).  The
multiverse, on the other hand, just is (or isn't, I suppose), like a rock
or a triangle.  It is not an interpretation or a story or a description.

> > Which backs off to the process that decided swe describes physical
> > > reality. Is there any mention why this is judged so important to be,
> > > reality would be willing to throw in a multiverse just to make it so?
> > >
> >
> > That last part doesn't seem to be a complete sentence. I'mt sure how to
> > parse it. Nor am I sure how to parse the first sentence fragment, though
> > there I'm guessing you mean "this [foregoing] raises the question of what
> > process was used to decide that the SWE describes physical reality".
>
> Dude, in the previous gone you had said MWI didn't come out of a process
> involving assumptions, including for local reality. You seemed to want to
> place the swe as the seed motivation. I
>

Was my interpretation of your sentence correct? I'm just trying to figure
out what you're talking about.  I'm not disagreeing with you or anything.
 Hopefully my interpretation was correct, and the paragraph below helps.
 Was it, and did it?

> It's clear that the SWE correctly predicts the outcome of physical
> > processes and experiments, to a very high degree of precision. That is to
> > say, it's probably not wrong in its domain of applicability. The "shut up
> > and calculate" folks have been using it very successfully for satellite
> > design, GPS, and lots of other applications. Your question appears to be
> > about whether we should "take it seriously" as describing ontologically
> > real things, specifically the part of it it says that any given
> interaction
> > has multiple outcomes, rather than the one we're used to. This is a
> harder
> > question of course. There are several competing interpretations of QM. I
> > think most serious physicists no longer think the Copenhagen
> interpretation
> > (instantaneous collapse) describes reality, so what your question boils
> > down to, I think, is: do any of the current interpretations of QM
> describe
> > reality? If so, which one? If not, where might we look? I'm afraid I
> > don't have much to offer on that topic. The SWE does such a good job that
> > I think QM describes reality. Collapse seems so obviously bad that
> > Copenhagen is out. That leaves violating locality (no FTL travel), or
> > causality (as commonly construed), or "realism", that events have only
> one
> > continuer. I favor the latter, which is MWI, because the others seem to
> > cause more troubles, and I'm reasonably comfortable with the main
> difficult
> > idea of MWI, that the world is a lot bigger than we thought -- it's
> > happened repeatedly throughout history.
> >
> > >
> > > Isn't this going to end up back to observing all the baffling things
> that
> > > throw classical realism out the window?
> > >
> >
> > Again I'm not sure how to parse that sentence. What is the "this"? And
> > what are the "baffling things"? And of course "classical realism" (by
> > which I assume you mean a Newtonian block universe) isn't even close to
> the
> > window anymore, it was gone nearly a century ago.
> >
> > >
> > > Doesn't that then become the starting point for why the swe must be a
> must
> > > have?
> > >
> >
> > I'm not sure what such a starting point would be. My starting point for
> > "why the swe must be a must have" is that it does an astoundingly good
> job.
> >
> >
> > > Maybe what
> > > > you're saying is the details of particular interatomic reactions
> typically
> > > > have no macroscopic influence. True, as far as it goes. If one photon
> > > > goes off in this direction and another goes off in another, that
> rarely
> > > > triggers vials of poison that kill cats.
> > >
> > > >
> > > >
> > > > > I keep hearing about the bizarre vanishingly improbable outcomes,
> but
> > > > > despite that saying nothing not already covered in
> probability/statistics,
> > > > > it looks to me like mwi only works conceptually when applied to
> humans and
> > > > > daft outliers.
> > > > >
> > > >
> > > > MWI by definition works when applied to physical objects - any or
> all of
> > > > them. I don't understand your comment above. How does MWI not apply
> to a
> > > > bouncing ball, for instance? MWI says solve the SWE; we see that the
> ball
> > > > is not relativistic so we can use Newtonian mechanics (which is a
> good
> > > > approximation for slow, "regular size" objects). We could in
> principle
> > > > solve the whole SWE for the ball + rest of system, but it's
> computationally
> > > > intractable (very).
> > >
> > > I would have said the relevant question to the context would be whether
> > > divergence of the ball ever sees macroscopic divergence of the ball.
> > >
> >
> > I don't know what that sentence means. What is "divergence of the ball"?
> > And how does divergence "see" anything? Maybe if you explain what
> > "divergence" is I'll get it.
>

OK, now I know what you mean by "divergence" -- different experimental
outcomes in different branches of the multiverse (a totally normal state of
affairs).  Here's how I analyze the ball case: in (virtually) all the
universes in which you and the ball exist, and you drop the ball, the ball
hits the table and bounces back -- the microscopic differences in position,
momentum, etc. all average out.  Of course there's a few where random
brownian motion of ball molecules line up and the ball goes wild, but those
are so very few they can almost always be ignored.  The exact height of the
bounce, however, will be a tiny bit different in all the different versions
of the experiment (different universes) due to tiny quantum differences
(how many photons hit the ball on the way down vs. up, and so on).

 Does that help?

> > > Or please explain why I'm wrong. But please if you do, first say a few
> > > > > words confirming what you think I think, otherwise I won't know if
> > > what you
> > > > > are saying helps me :o)
>

Indeed, this is what I've been trying to do.


> > > > I'm not sure if you're wrong or not, since I don't understand your
> claim.
> > > > (And even then who knows if I'd have the knowledge to say if you're
> wrong.)
>

...> > > > p.s. there are other categories of major problem. What about the
> fact MWI
> > > > > is created by integrating QM with a load of assumptions....that
> never get
> > > > > any kind of treatment or analysis. Lots of implicit assumptions in
> there
> > > > > too.
> > > > >
> > > >
> > > > Well, let's take one thing at a time. But MWI is not created by
> > > > "integrating QM with a load of assumptions". It's defined by
> removing the
> > > > collapse postulate and taking the rest (the SWE) as a description of
> actual
> > > > physical reality (not just numerical fictions). That latter is
> indeed an
> > > > assumption that distinguishes MWIers from the "shut up and calculate"
> > > > crowd, but they have no model at all for what is "real" -- they
> don't care
> > > > as long as the math comes out.
> > >
> > > If you want to throw out the local realism rationale for the swe thing,
> > > then it'd just become whatever reason goes in its place
> > >
> >
> > Local realism is not a rationale for "the swe thing" -- the SWE is what
> it
> > is. If you don't add the collapse postulate, you get something that is
> > local, but not "realistic" (single-valued) - i.e. MWI. If you throw out
> > locality, you can add collapse or various other things. And so on. None
> > of these are rationales for SWE, they're consequences of it. What you
> > can't have is the SWE plus local realism (and causality as usually
> > understood). It's internally inconsistent.
> >
> > (I don't want to go off on a tangent, but I'll reiterate my common
> refrain
> > that "realism" as a QM term meaning single-valued is emotionally loaded
> > [who would want an UNrealistic theory??] and not even correct. The MWI is
> > perfectly "realistic" in the common sense; that's why I prefer to use
> > single-valued instead. Someone else here recently suggested another term
> > for it, which I can't remember now.)
> >
> > > > > I think you, Deutsch, basically all of you, are seriously mixed up
> about
> > > > > what you can and cannot do with unexamined assumptions in vague
> form
> > > > > effectively treated as constants.
> > > > >
> > > >
> > > > You could be right. What's an example of an unexamined assumption
> that's
> > > > being treated as a constant?
> > >
> > > - unless local realism gets treated in a process that explores what
> > > exactly is being suggested about local realism, and whether that can be
> > > better fitted. Then a process that establishes it thinks this is the
> only
> > > way local realism can be preserved in light of the quantum effects.
> > >
> >
> > Your first sentence is incomplete. I have no idea what it means, nor if
> > it's an answer to my question. Your second sentence is English but I
> still
> > can't make sense of it. How does a process think?
> >
> > > Which presumably then has eliminated, for example, the scenario where
> local
> > > realism, space and time existed prior to the big bang, and are
> *re*emergent
> > > effects, and what QM is telling us is something about what it took for
> that
> > > sort of complexity to successfully reassemble after being broken down,
> and
> > > squirted through the needle of a camels eye.
> > >
> >
> > Since I couldn't parse the sentence before this, I don't understand the
> > "which" (first word). And I'm not sure what any of this has to do with
> > before or after the big bang. And of course I don't think "local realism"
> > is possible at all in a QM world.
> >
> >
> > > That would also preserve local reality in light of the quantum effects
> > >
> >
> > Sorry, what would preserve this?
> >
> >
> > > , but exchanging a through the camels eye puzzle for a multiverse.
> > >
> >
> > I don't really understand the "through the camels eye puzzle". I have a
> > vague feeling you are trying to convey something about information
> transfer
> > during the big bang, but I'm not sure what it is or why it's relevant.
> >
> > > Maybe you would prefer the multiverse because maybe that feels like a
> > > solution not a problem. But on the other hand a through the camels eye
> > > problem is accessible via the scientific approach along many lines. And
> > > while the explanation leaves quantum mechanics still to be resolved,
> what
> > > it does do is point squarely the direction to where that solution will
> be
> > > found, and that will be the big bang
> > >
> >
> > Sorry, what is the explanation which points in that direction? (And
> what's
> > it an explanation of?) I missed that.
> >
> >
> > > So, which is the better, more robust, more researchable, and overall
> more
> > > promising explanation.
> > >
> >
> > I assume that's a question despite the period. Unfortunately I don't know
> > what the two explanations being evaluated are. I assume one is QM and/or
> > one of its interpretations.
> >
> >
> > > So more realistic by far because things get profoundly more realistic
> when
> > > something new is discovered, or equally promising, thrown out.
> > >
> >
> > Again, I'm not sure what that sentence fragment refers to, nor its
> meaning.
> > Sorry.
> >
> > --
> > Gary
> >
>
> Gary - You're a good guy and we're comfortable. It's up to you of course,
> but if you find yourself at the end of a reply to me, and pretty much every
> one of your responses is saying you don't parse this, or you don't see the
> point, and so on. Unless there's some burning reason that you want to keep
> running the thread, feel free to choose to discard before sending :O)
>

Sorry, don't mean to appear mean or anything.  I think you probably have a
really interesting idea in here; I know you've spent a lot of time thinking
deeply about these things.  I want to understand what you have to say.   I
just have a hard time figuring out what you're trying to say sometimes.  It
might take me a few tries.  Sorry if I appear pedantic; I really am trying.
 As a scientist I think it's important to be clear in terminology and say
things as plainly as possible; it seems to be the best way to get at the
truth and avoid talking at cross-purposes.

Now that I've explained that MWI is local but not "realistic" (single
valued), how does that affect your idea?

-- 
Gary


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