- --- In bell_bohm@egroups.com, Eric Dennis <edennis@p...> wrote:
> Welcome Tom...

the

>

>

> Nope. No more or less unobservable than a classical potential. It

> influences particles, and we can detect that influence by detecting

> particles (their positions/momentat/etc).

This makes perfect sense.

>

potential,

> > (2) "hides" the uncertainty. In other words, the quantum

> > if it could be observed, would have quantities that would not be

or "indeterminate"

> > possible to measure with complete precision.

>

> No again. Nothing is inherently imprecise or ambiguous

> in dBB. The only difference between the "quantum potential" and a

field

> classical potential is that the former is not associated with any

> occupying physical space (x,y,z). If you want you can say it's

associated

> with the wavefunction as a "field" (not in the QFT sense), but the

space

> wavefunction exists not in physical space but in the configuration

> of the entire system (e.g. for N particles, config space has 3N

Yes, this does help a lot. Thank you for taking the time to answer.

> dimensions).

>

> Hope that helps.

>

> --Eric

So the only real problem with the Bohm/de Broglie interpretation is

that the quantum potential is an entity that can move faster than the

speed of light, and thus relativity is violated?

I have also heard that the Bohm/de Broglie interpretation has not

been extended to systems of more than one particle, but your previous

answer seems to suggest that this is not the case. Am I correct in

assuming that dBB has been extended to systems of more than one

particle?

Does dBB answer the paradoxical nature of correllated systems that

consist of states with probabilities that cannot be constructed by

linear combination of the individual states making up the correllated

system? Does this convoluted question make any sense?!

Tom - Tom wrote:

> Yes, this does help a lot. Thank you for taking the time to answer.

Right. There are influences moving faster than light (FTL), described by

> So the only real problem with the Bohm/de Broglie interpretation is

> that the quantum potential is an entity that can move faster than the

> speed of light, and thus relativity is violated?

the quantum potential, violating fundamental relativity. It should be

emphasized that any theory reproducing the QM predictions (including

standard QM itself) implies FTL influences, which is the point of Bell's

Theorem.

> I have also heard that the Bohm/de Broglie interpretation has not

dBB does cover many particle systems--in fact, it's only here that the FTL

> been extended to systems of more than one particle, but your previous

influences occur. For many particle systems, the wavefunction and quantum

potential are functions of _all_ the degrees of the freedom, which is what

gives rise to the non-locality.

> Does dBB answer the paradoxical nature of correllated systems that

I think what you mean is correlated systems involving wavefunctions which

> consist of states with probabilities that cannot be constructed by

> linear combination of the individual states making up the correllated

> system? Does this convoluted question make any sense?!

are not factorizable into a _product_ of sub-system wavefunctions. Indeed

it is precisely these "entangled" states which exhibit FTL influences in

any version of QM, including dBB.

You might also be getting at von Neuman's "refutation" of hidden variable

theories--now understood to be invalid--which made a point about linear

combinations of _operators_ and the linearity of their expectation values.

Eric