Re: Macroscopic Emergence in MWI worlds

On Mon, Aug 19, 2013 at 11:55 AM, hibbsa <hibbsa-/[email protected]> wrote:

> **
>
>
>
>
> --- In [email protected], Gary Oberbrunner <garyo@...>
> wrote:
>
> >
> > On Thu, Aug 15, 2013 at 11:56 AM, hibbsa <hibbsa@...> wrote:
> >
> > > > The issue arises when you converge, on the one hand, the
> > > requirements our own macroscopic world need to meet in order to be
> > > consistent, reliable, repeating and ultimately deterministic. With, on
> the
> > > other hand, the supposition all or most instances of quantum behaviour
> > > involves or is associated with some emergence.
> >
> >
> > If this is the issue, I'm not sure what the issue is. Emergence generally
> > (not always, but mostly) smooths out low-level randomness or lumpiness
> into
> > consistent, reliable, deterministic macroscopic behavior, which is what
> > you're hoping for. Low-level quantum phenomena have lots of randomness;
> > averaging over lots of those universes (or lots of instances in one
> > universe) gives nicely predictable emergent properties like temperature,
> > energy and entropy, or in another domain, predictable, stable giant ant
> > hills from fairly random individual ant behaviors.
> >
> > ps: if you see this, it means I can post to FoR again.
> >
> > --
> > Gary
> >
> >
> > [Non-text portions of this message have been removed]
> >
>
> Gary, I think it's probably more reasonable to assume a lot more
> emergence, in a lot more ways, than what might readily come to mind.
>

Such as?

>
> What is the problem. Well look, emergence is definitively independent of
> the how the underlying quantum effects pan out. Which is the same as
> saying, it's independent of the sort of variation produced by divergence.
>

I'd say most emergent properties result from averaging large groups of
properties.  (Not all of course; conscousness is possibly an emergent
property of brains or other things.)  But yes, changing some minor property
at the lower level typically has little effect on the macroscopic realm.
"Butterfly effects" are the canonical counterexample, but they are
comparatively rare.


> 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.  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).


> 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)
>

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.


> 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?


-- 
Gary


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