Re: Configuration Space
--- In firstname.lastname@example.org, Travis Norsen <norsen@...> wrote:
> I think there is some wire-crossing happening here. According to dBB,
> the wave function has to be taken as *physically real*. It is every
> bit as physically real as the particles (though that is admittedly
> *weird* since the wf doesn't live in normal physical 3 space). If
> anyone is thinking of the wave function as "potential" (in the
> sense that contrasts with "actual", as opposed to the E&M sense
> of "the potentials" vs "the fields"), as merely just some kind of
> abstract way of keeping track of all the configurations the particles
> *might* be in, that is *wrong* -- meaning, that is not dBB. The wave
> is a crucial part of the ontology. It *guides* the partcles.
If both the particles and the waves were not both considered real I wouldn't give dBB the time of day. To be honest after Gibbon's came out with his book that featured Crammer's Transactional interpretations I toyed with this briefly but came back to dBB for in the end it had as much voodoo as MWI.
> Saying "the particles define what the actual case is" is dangerous
> and misleading. A complete specification of the physically real
> situation (according to dBB) would have to include not just the
> positions of the particles, but also the configuration of the wf.
> That is, "the actual case" is not exhausted by information about the
> particles only. Of course, the wf is "hidden" in the sense that we
> don't *see* it directly. When we look and see tables, we are seeing
> table-shaped arrangements of *particles*. We have to infer the
> existence of the wave from such facts as that the particles in a
> 2 slit experiment tend to show up in what looks suspiciously like
> an interference pattern. But none of this makes the wf any less
> *real*, any less *actual* (any more than it makes atoms or the
> insides of stars un-real or "merely potential" that we can't see them
I agree with what your saying but some recent exposure I've had to professional physicists (other then yourself) has had me subjected to this point as their strongest point of objection. At the same time they talk about subquantum theories containing strings, loops, branes, and oodles of dimensions and feel these are to be considered completely reasonable. I think many of them should take some serious time out for a reality check.
> Maybe nobody is actually confused about this, but it does seem like
> the word "potential" (in the E&M sense, which I introduced by way of
> suggesting a different version of dBB with attributes different
> ontological status to the wf) is being confused with "potential" in
> the other sense. And yes, they are somewhat related, since regarding
> the wf as a potential (in the E&M sense) means regarding it as *not
> physically real* (but only a mathematically convenient device for
> calculating whatever *is* physically real). But still, let's try to
> keep the wires uncrossed.
Yes we must keep everything from getting confused I agree. As you say that is to use potential mathematically the same way as EMT should not have us think of the wave potentail in the same way as it's used in EMT where what it represents is not actually real.. Interesting thing regarding that though is that in regular EMT when one uses the potentail field approach for using Coloumb gauge equations and takes the potential too seriously one can end up where the potential has a nonlocal quality. This can be disregarded only because the potential is not to be considered real for EMT as you say. I find that kind of ironic in terms of how you propose we treat this potential in the case of dBB.
> > If you can deduce what the six-dimensional,
> > two-particle guidewave would be when given a pair of
> > three-dimensional, two-parameter, one-particle guidewaves (that is,
> > each guidewave takes the same two particles as parameters; but each
> > only guides one particle), then I'll be comfortable in consigning
> > configuration space to the status of purely mathematical formalism.
> Note that you can't deduce the E&M potentials from the E and B fields.
> You can go from the potentials to the fields, but not the other way,
> because of gauge freedom. There are many different potentials which
> correspond to the same fields, i.e., which correspond to the same one
> physically real configuration. But this is no objection to classical
> E&M. And so I think the parallel objection you are hinting at here
> is also invalid. In general, asking whether one can recover the
> config space wf from whatever is postulated as physically real, is the
> wrong question because it *presupposes* the fundamentality of the
> config space wf. But the whole point of the exercise is to demote
> the config space wf. If you can get the right dynamics for the
> particles (and hence the right empirical predictions) without granting
> the config space wf "beable status", then you're done -- you've
> succeeded -- and there's no further (valid) worry here.
Only if you take the potential itself too seriously. For me its all much of a muchness, in as I have never considered config space anything other then a mathematical dimensional space in the first place (sort of a Platonic realm thingy). The advantage as you point out is that in doing this we can get rid of it in a practical way.. Why not go up another notch and try to express it all in terms of a tensor field approach where the wave could perhaps get a little more beefy as it perhaps being in some way able only to exist due to the presence of the particle. This would be something along the lines of that bow wave toy theory thing I imagined many years back. Einstein would have perhaps liked such a approach as he was the king of the tensor. This is way beyond my abilities however.
> There's no such thing (in my proposal) as "a wave-collapse element"
> if that means some extra postulate that has to be added to make things
> work out correctly. The waves collapse automatically.
I dislike this OQM term collapse altogether. In OQM when a particle hits the screen it's called a collapse. For me that's like saying when a tsunami lifts my boat from the water and crashes it into a building onshore that this indicates that my boat only took on its observed form when it hit the building. And yet that is the stuff that OQM is built on. In this regard I like what Durr, Goldstein and Zangh had to say in one of those papers you just recommended and that was:
"Perhaps this paper should be read in the following spirit: In order to grasp the essence
of Quantum Theory, one must first completely understand at least one quantum theory."
The key word here of course is 'understand" which so dismisses OQM as a choice to consider in such a case. Who ever said physicists don't have a sense of humour?
--- In email@example.com, "Jonathan Lang" <dataweaver@...>
>Yes as you say its mentioned in the Goldstein and company paper. Also, I
> In the papers that Travis pointed to in the "Configuration Space"
> thread, there was a discussion about this sort of thing. The
> impression that I got is that we "just happen" to live in a region
> with a "quantum equilibrium distribution" for the same sort of reason
> that coin tosses "just happen" to produce a mix of heads and tails,
> rather than a constant string of one or the other. Check out the
> papers and let me know what you think.
have always been aware of the postulate in dBB. What I wasn't aware of
is that there is some reason to suspect that there could exist some
matter that doesn't hold to this. As for your head and tails thing as
Valentini explains it boils down to a chicken and egg thing. However in
this scenario nonequalibrium ruled the early universe and we come to
where we are over time. I find that interesting for one of the problems
with cosmology is what's called the horizon problem where it's had to
explain the current similarity throughout the universe if communication
within it is limited in terms of speed. I find it interesting that dBB
could offer a plausible explanation for this.
> Also, it wouldn't surprise me to learn that "nonequilibrium" doesn'tThat to is interesting for what would actually be the reaction. Let's
> get conserved: that is, if you take a sample of matter in a
> nonequilibrium distribution and bring it into contact with a sample
> in an equilibrium distribution, it's entirely possible that the latter
> would convert into the former. In effect, "nonequilibrium" is
> unstable, while "equilibrium" is stable.
speculate for a minute that WIMP's actually represent this stuff. If
that were the case we would not get hardly any reaction at all for
that's why they are called such (weak interacting massive particles).
This really means they don't interact much with regular matter or
themselves(at least not in the normal way). Then we have anti-matter
where the reaction is so strong that all one ends up with are photons.
I'm not as certain as you are in all this. With current evidence in
cosmology suggesting that what we take as regular matter and regular
energy only making up 4 percent of the sum total are you sure which side
of the looking glass we are on?