The Myth of Wave-Particle Duality

[Demystifier]

Since Ballentine believes in Bell's Theorem being violated. And he believes a particle has position at all times. Then consequence is the particles are somehow connected non-locality... what else but superluminally...

Yes, that's a correct line of reasoning. Do you see a problem with it?

 

[Varon]

OK, thanks for the quotation.


Yes I do. Do you?

Hmm... You are a Bohmian. Here positions are preferred. Bohm made two additional assumptions. That there is quantum potential and omnicient wave function for each particle.

How come Bohm didn't think of Ballentine position that quantum potential and omnicient wave function are not necessary. Ballentine Statistical Interpretation is NOT being agnostic (one can get this impression if one didn't read his paper and book). He gave the mechanism even of one particle behavior in the double slit. Which is that the particle is scattered with angle and trajectory (see details in posts above).

Maybe Bohm has to put the 2 additional assumptions because he wants the wave behavior to exist in one particle? But if he didn't assume this. It will become a Ballentine Interpretation?

 

[Varon]

Yes, that's a correct line of reasoning. Do you see a problem with it?

It violates Einstein Special Relativity...

But... since no information is transfered. The spirit of SR is not really violated... Hmm... But Lorentz invariance is violated.. and it is not compatible with quantum field theory.. or interacting particles.. hence Ballentine interpretation is very nearly falsified.

I hope other non-Bohmian can comment on this. Demystifier is a Bohmian and may be biased on certain aspect.

Hmm... Can't we even differentiate whether observation creates the properties like position of particles against them always existing at all times... and whether the superluminal link is direct from particle to particle or the non-local link is in the measurement outcomes? My God. Let's design experiments to distinguish them. I think we can. We have to try hard enough. Anyone can think of any Nobel calibre experiment to distinguish them?

 

[SpectraCat]

Ballentine paper assumes all particles have positions at all times. This means in Bell's Theorem. He indeed believed that the particles were connected with superluminal link? In Ballentine 1989 textbook which I studied, he mentioned:
Question. Anything wrong by assuming entangled particles exist at all times even 100 billion light years away and since Bell's Theorem is violated, they really are connected with superluminal link? This is the consequence of Ballentine's Statistical Interpretation.

Bohr arguments was the particles attributes like position didn't exist before measurements, so there was no non-local link because the particles wasn't there at all.

That's actually a really good point. I think the Aspect experiments pose a real problem for the statistical interpretation .. at least in the form proposed by Ballentine. I also read his comments on those experiments in his book, and I found his handling of the issue quite weak and speculative .. he certainly didn't show how his theory could explain Apsect's results .. he just seemed to hope an appropriate loophole would be found later on. To me it seems like the statistical interpretation may actually be an LHV theory, and as such, should be inconsistent with QM according to Bell's theorem.

[EDIT: What I should have said above is that the statistical interpretation requires EITHER local hidden variables, OR it requires superluminal hidden variables. I guess this is what Demystifier said when he described Bohmian mechanics as a specific realization of the statistical interpretation, because BM requires the quantum potential (or equivalent) which takes care of the superluminal stuff.]

 

[Demystifier]

Bohm made two additional assumptions. That there is quantum potential and omnicient wave function for each particle.

That's not quite correct. The Bohmian approach needs only ONE of these two assumptions, because they are equivalent. And not for each particle separately, but for all particles at once.

Maybe Bohm has to put the 2 additional assumptions because he wants the wave behavior to exist in one particle? But if he didn't assume this. It will become a Ballentine Interpretation?

Well, I like to view the Bohmian interpretation as a concrete realization of the more general Ballentine interpretation.

 

[zonde]

Since Ballentine believes in Bell's Theorem being violated.

I see no justification for that statement.

 

[Demystifier]

It violates Einstein Special Relativity...

But... since no information is transfered. The spirit of SR is not really violated... Hmm... But Lorentz invariance is violated.. and it is not compatible with quantum field theory.. or interacting particles.. hence Ballentine interpretation is very nearly falsified.

I hope other non-Bohmian can comment on this. Demystifier is a Bohmian and may be biased on certain aspect.

It's true that I am biased (is there anybody who isn't?), but I must react to this. There are variants of the Bohmian interpretation which are nonlocal, but Lorentz invariant and compatible with quantum field theory and even interacting particles. See
http://xxx.lanl.gov/abs/1002.3226 [Int. J. Quantum Inf. 9 (2011) 367-377]
http://xxx.lanl.gov/abs/0904.2287 [Int. J. Mod. Phys. A25:1477-1505, 2010]
http://xxx.lanl.gov/abs/1007.4946

 

[Demystifier]

I see no justification for that statement.

He probably ment Bell's inequality ...

 

[Varon]

I see no justification for that statement.

He said it in page 610 of his textbook. Ballentine wrote:

"If quantum mechanics implies nonlocality, i.e. influences that are not restricted by the speed of light between distant regions, can we make use of them to send messages at superluminal speeds? No! Several people have shown that quantum correlations cannot be used to transmit messages at superluminal speeds. This is so because the locality principle used in the derivation of Bell’s inequality is stronger than the weaker locality principle that prevents superluminal transmission of information, and quantum mechanics satisfies
the latter (Ballentine and Jarrett, 1987)."

~~~~~~~~~~~~~

So Ballentine considers the possibility of nonlocality as he was aware of Aspect experiment and others. And since he believes position exists at all times. The particles are connected superluminally. Familiar with the EPR debates? It's related to this.

Anyway. After realizing that "Bohmian interpretation as a concrete realization of the more general Ballentine interpretation" and consider I prefer Copenhagen due to its more elegant "Observation creates reality" or Many Worlds where I get to be President of United States in one of the branches, then I leave it for the Bohmian to develope the theory further.

 

[SpectraCat]

That's actually a really good point. I think the Aspect experiments pose a real problem for the statistical interpretation .. at least in the form proposed by Ballentine. I also read his comments on those experiments in his book, and I found his handling of the issue quite weak and speculative .. he certainly didn't show how his theory could explain Apsect's results .. he just seemed to hope an appropriate loophole would be found later on. To me it seems like the statistical interpretation may actually be an LHV theory, and as such, should be inconsistent with QM according to Bell's theorem.

I think that what I should have said above is that the statistical interpretation requires EITHER local hidden variables, OR it requires superluminal hidden variables. I guess this is what Demystifier meant when he described Bohmian mechanics as a specific realization of the statistical interpretation, because BM requires the quantum potential (or equivalent) which takes care of the superluminal stuff. Is that correct?

 

[Demystifier]

I think that what I should have said above is that the statistical interpretation requires EITHER local hidden variables, OR it requires superluminal hidden variables. I guess this is what Demystifier meant when he described Bohmian mechanics as a specific realization of the statistical interpretation, because BM requires the quantum potential (or equivalent) which takes care of the superluminal stuff. Is that correct?

Yes, I would agree with that. And from the Ballentines textbook, it seems that he finds nonlocal hidden variables to be a more viable option.

It's also interesting to see what he says about the Bohmian interpretation (in the same textbook):
"The most important consequence of Bohm's theory is its demonstration that, contrary to previous belief, it is logically possible to give a more detailed account of microscopic phenomena than that given by the statistical quantum theory. The significance and utility of the resulting quantal trajectories, however, remain controversial."

 

[Varon]

That's not quite correct. The Bohmian approach needs only ONE of these two assumptions, because they are equivalent. And not for each particle separately, but for all particles at once.

Quantum Potential and the Bohm Omniscient Wave Function (BOWF) is equivalent? I thought BOWF is pure information only while the Quantum Potential is some kind of force that pushes the particle to either pass thru the left or right slit depending on how the BOWF able to detect configuration changes even a billion light years away.

I read in a book someone asking how a particle can be pushed. Some suggest a electron may have an internal part and there may be some kind of nano-jetpack that can manuever it. Lol... So how can the particle be influenced to take the left or right slit? Don't say initial condition, take a case where a quantum potential can influence it.. what's a good example?

Well, I like to view the Bohmian interpretation as a concrete realization of the more general Ballentine interpretation.

 

[Demystifier]

So how can the particle be influenced to take the left or right slit? Don't say initial condition, take a case where a quantum potential can influence it.. what's a good example?

To say "initial condition" is not in contradiction with saying that it is influenced by the quantum potential. Both answers are correct, so it's not clear to me what kind of an answer do you actually want.

Or consider a CLASSICAL particle. What will determine the slit through which the particle will pass? Initial position? Classical force derived from a classical potential? Isn't it obvious that both answers are correct?

 

[Varon]

To say "initial condition" is not in contradiction with saying that it is influenced by the quantum potential. Both answers are correct, so it's not clear to me what kind of an answer do you actually want.

Or consider a CLASSICAL particle. What will determine the slit through which the particle will pass? Initial position? Classical force derived from a classical potential? Isn't it obvious that both answers are correct?

I thought that in the concept of quantum potential. Even if the initial condition is equal.. meaning the particle is sent off from the emitter straight. The quantum potential can push the particle while in mid flight.. this is why they mentioned it in the book (I forgot the title) how the electron may have structure that allows this propulsion system.

 

[Demystifier]

Even if the initial condition is equal.. The quantum potential can push the particle while in mid flight..

What you suggest here may be achieved with a time dependent quantum potential, provided that two particles are fired at different times. However, in a typical 2-slit experiment the quantum potential is usually time-independent to a great accuracy.