Defending Bohmian Trajectories: A Critical Analysis of ESSW and Hiley's Papers

[olcay]

Hi,

Some of you may have read this article about defence of Bohmian trajectories against ESSW papers.

Quantum Trajectories, Real, Surreal or an Approximation to a Deeper Process?
B. J. Hiley, R. E. Callaghan and O. Maroney.

http://arxiv.org/abs/quant-ph/0010020"

In a nutshell it says ESSW papers And Aharanov made a mistake about bohmian mechanics and indicate that bohmian trajectories are not surrealistic but appropriate for commonsense.

I read their papers in detail but the heart of this paper made me confused;

"As the atom passes through the interference region I, a new quantum
potential energy is generated. It must be emphasised that since this energy
arises from equation (25) using equation (1), it must of necessity include
the quantum potential energy stored in the ‘cavity’. It is this coupling that
gives rise to any exchange of energy between the ‘cavity’ and the atom so
that when the atom emerges from the region I, it has regained its original
energy and the ‘cavity’ is no longer excited. In other words the process has
been truly ‘erased’.
If the particle follows the other route, the ‘cavity’ is not excited until the
particle reaches the region of interference. Here the wave packet carrying
information about the ‘cavity’ comes into effect and energy, in the form of
quantum potential energy, is again redistributed so that the cavity becomes
excited and the atom loses energy if it is traveling along one of the ‘reflected’
trajectories."

It says the alerted cavities' energy is regained by the atom when interfere with its empty wave and adversely, its energy alert the cavity when it interfere with its wave with particle.

Is there any bohmians who can explain what's going on?

 

[Demystifier]

I am not sure that I completely understand the argument above, but I do agree that the so called "surrealistic trajectories" do NOT represent a problem for the Bohmian interpretation. Perhaps the best argument for this is given by Aharonov and Vaidman (who are actually not proponents of the Bohmian interpretation) in
http://xxx.lanl.gov/abs/quant-ph/9511005
The point is that "surrealistic" Bohmian trajectories do not agree with trajectories measured WEAKLY, where a weak measurement of a trajectory cannot be considered a true measurement of the trajectory. In essence, the weak measurement of a trajectory is based on a naive (classical like) extrapolation by truly measuring only the final position of the particle. Therefore, one should not be surprised that it disagrees with the Bohmian trajectory that is assumed to be the actual trajectory.

See also
https://www.physicsforums.com/showthread.php?t=252491

 

[ZapperZ]

Hi,

Some of you may have read this article about defence of Bohmian trajectories against ESSW papers.

Quantum Trajectories, Real, Surreal or an Approximation to a Deeper Process?
B. J. Hiley, R. E. Callaghan and O. Maroney.

I did a quick search on this paper and could not find where this was published other than the arXiv version. For all the physics forums other than HEP and BTSM, we strongly require that the references and discussion be based on properly published material, since the subject areas involved still principally use peer-reviewed material.

If you have a proper source where such a paper has been published, please give the complete citation. If not, then you need to ask yourself if something that appeared in 2000 and STILL isn't published is legitimate enough to actually warrant this type of discussion.

Zz.

 

[olcay]

"A quantum potential approach to the Wheeler delayed-choice experiment" -
Nature 315, 294 - 297 (23 May 1985); doi:10.1038/315294a0

"What is Erased in the Quantum Erasure?" Foundations of Physics Volume 36, Number 12 / December, 2006 DOI 10.1007/s10701-006-9086-4

In these papers authors mention about same subject, in same way-analogy-arguments...

I did a quick search on his other papers and could find some articles where these was published other than the arXiv version. For all the physics forums other than HEP and BTSM, we strongly require that the warnings about citations and prejudgement about subjects be based on properly published material.

Now you should need to ask yourself if something may have been published somewhere else with different title before judging someone.

:)

 

[ZapperZ]

"A quantum potential approach to the Wheeler delayed-choice experiment" -
Nature 315, 294 - 297 (23 May 1985); doi:10.1038/315294a0

"What is Erased in the Quantum Erasure?" Foundations of Physics Volume 36, Number 12 / December, 2006 DOI 10.1007/s10701-006-9086-4

In these papers authors mention about same subject, in same way-analogy-arguments...

I did a quick search on his other papers and could find some articles where these was published other than the arXiv version. For all the physics forums other than HEP and BTSM, we strongly require that the warnings about citations and prejudgement about subjects be based on properly published material.

Now you should need to ask yourself if something may have been published somewhere else with different title before judging someone.

:)

I didn't judge. I questioned why a paper from 2000 hasn't been published. Since, as you claim that there are other papers on the same topic that have already been published, then why not use those as the foundation of the discussion, rather than something that hasn't?

Furthermore, there's no reason to produce an identical paper after the same content has been published elsewhere. So either the arXiv paper you cited isn't the same as the ones already published (and therefore, calls into question why it hasn't been published after all this time), or the authors are simply recycling the same thing. Either way, the arXiv paper should not have been used as the source of the discussion.

Zz.

 

[olcay]

Ok, you are right. I'm just kidding. But I did not claim any argument as truth or any paper as a proper article. Just asked a few about what that text is trying to say. No need for scientific elitism(which is really necessary when arguing latest findings).

other papers I mentioned, of course, are not identical. They argue same thing with different facts. But the main idea is identical: "Bohmian trajectories are not surrealistic as ESSW papers defend"

Anyway, I know there are bohmians here. And I'm trying to understand what do they tell about these quantum erase.

Ant still waiting...

 

[ZapperZ]

Ok, you are right. I'm just kidding. But I did not claim any argument as truth or any paper as a proper article. Just asked a few about what that text is trying to say. No need for scientific elitism(which is really necessary when arguing latest findings).

The same way that I wasn't "judging" the paper, this also has nothing to do with "scientific elitism" (who is now "judging" who?). The use of arXiv sources are common in HEP and String/QG/etc. as practiced by physicists in these fields. Thus, such sources are allowed in those areas and in the respective forum here in PF. In other fields, the use of peer-reviewed papers is STILL the predominant source of information. That is why we go by the standard practice.

Please stick to only peer-reviewed sources from now on.

Zz.

 

[olcay]

I'm dazzled...

In case of defending an argument, rules you mentioned should be rational and efficient. But To point a paper to ask stg. about a subject, isn't it so weird to forbiden talking about it because it's unpublished? When was it accepted as unscientific to discuss(not to defend!) a paper?

And c'mon! it's B.J. Hiley we are talking about on! It's not the same of course but if you found a 'lost' paper of Heisenberg that was not published, What would you do? Don't you even talk about it(Oh rules, Glory rules!)?

But, OK. you're the mentor. You know your rules. Enjoy it. I only wanted to say my ideas.
Never cite to arxiv anymore...

 

[Demystifier]

Anyway, I know there are bohmians here. And I'm trying to understand what do they tell about these quantum erase.

Ant still waiting...

Haven't you seen my post?

By the way, I completely agree with you that it should be allowed to discuss about someone's opinion even if this opinion is not published in a peer-reviewed journal. After all, this IS the idea of this forum, to discuss and exchange our opinions without publishing them. But the rules are the rules, even when you disagree with them.

 

[ZapperZ]

After all, this IS the idea of this forum, to discuss and exchange our opinions without publishing them. But the rules are the rules, even when you disagree with them.

I'm not sure where you got the idea that this IS the idea of this forum. A quick read of the PF Guidelines does not say that.

Furthermore, one can already see the intent of this forum simply by looking at our policy on personal, unverified, and unpublished theory - the IR forum. The FACT that we do not allow such discussion in the main part of PF clearly indicates the "idea" of this forum.

Zz.

 

[olcay]

Demistifyer,

Sorry to ignore you. I meaned "more other bohmians". :)

Yes, rules are rules. I will continue to ask my questions with published papers of Hiley anymore.

 

[Demystifier]

I'm not sure where you got the idea that this IS the idea of this forum.

Perhaps you misunderstood me, so let me explain what I mean.
The idea of the forum (not only this, but any forum) is to make discussions, right?
To discuss, means to write your opinion and to read the opinions of other people, right?
During these discussions, we can refer to statements of other people (for example, in this post I refer to your statement "I'm not sure where you got the idea that this IS the idea of this forum."), right?
But referring to an arXiv paper is nothing but a referring to an opinion of another person. So what is the difference? Why it is allowed to say "Prof. Witten said that ...", but it is not allowed to say "On arXiv Prof. Witten have written that ..."? I simply do not understand the purpose of this rule.

Or let me be more specific. Let us assume that olcay and me find the arXiv paper of Hiley interesting. We would like to discuss about that paper. It is not our attention to convince anybody else that this paper is good, but merely to have our own discussion about that. Are you suggesting that in that case we should discuss it by private messages only? Or are you saying that we can discuss about that paper freely, provided only that we do not specify what arXiv paper we are talking about? Sorry, but it simply does not make sense to me.

 

[ZapperZ]

Perhaps you misunderstood me, so let me explain what I mean.
The idea of the forum (not only this, but any forum) is to make discussions, right?
To discuss, means to write your opinion and to read the opinions of other people, right?
During these discussions, we can refer to statements of other people (for example, in this post I refer to your statement "I'm not sure where you got the idea that this IS the idea of this forum."), right?
But referring to an arXiv paper is nothing but a referring to an opinion of another person. So what is the difference? Why it is allowed to say "Prof. Witten said that ...", but it is not allowed to say "On arXiv Prof. Witten have written that ..."? I simply do not understand the purpose of this rule.

Or let me be more specific. Let us assume that olcay and me find the arXiv paper of Hiley interesting. We would like to discuss about that paper. It is not our attention to convince anybody else that this paper is good, but merely to have our own discussion about that. Are you suggesting that in that case we should discuss it by private messages only? Or are you saying that we can discuss about that paper freely, provided only that we do not specify what arXiv paper we are talking about? Sorry, but it simply does not make sense to me.

But if you have followed many of my posts, whenever someone said "I heard that... " or "I read that...", I've always asked for a specific, exact citation! And when it came from either unpublished, or non-standard sources, that person will get the SAME response as what I'm giving now.

Are there exceptions to this rule? Sure there are! Many speeches by prominent figures, etc. are never published, but are still uploaded to ArXiv. Can these be discussed? Sure they can! However, when something is purported to be a "publication", or a work that should be peer-reviewed, then that is what it should be.

So which part of this doesn't make sense still?

Zz.

 

[Demystifier]

Are there exceptions to this rule? Sure there are! Many speeches by prominent figures, etc. are never published, but are still uploaded to ArXiv. Can these be discussed? Sure they can! However, when something is purported to be a "publication", or a work that should be peer-reviewed, then that is what it should be.

So which part of this doesn't make sense still?

In this form, it makes perfect sense.

 

[olcay]

Many speeches by prominent figures, etc. are never published, but are still uploaded to ArXiv. Can these be discussed? Sure they can! Zz.

Isn't B.J. Hiley a prominent figure? What's the standard? Publish a list of prominent figures.

 

[ZapperZ]

Isn't B.J. Hiley a prominent figure? What's the standard? Publish a list of prominent figures.

And that paper you cited was a speech that was never meant to be published?

Here's the deal. Very much like discussing "religion" on PF, you discuss unpublished work outside of HEP/BTSM topics at your own risk. We judge it case by case. Want to ensure that you can discuss something? Make sure it has been published. That's your only certainty.

Zz.

 

[atyy]

In a nutshell it says ESSW papers And Aharanov made a mistake about bohmian mechanics and indicate that bohmian trajectories are not surrealistic but appropriate for commonsense.

It says the alerted cavities' energy is regained by the atom when interfere with its empty wave and adversely, its energy alert the cavity when it interfere with its wave with particle.

This paper comments on Hiley et al's arXiv paper with regard to the first point, but not the second:
Bohmian Histories and Decoherent Histories
James B. Hartle
http://arxiv.org/abs/quant-ph/0209104

Hiley's and Callaghan's 2006 Foundations of Physics paper which you mentioned elaborates on the second point. An online version of it comes up on Google:
http://www.bbk.ac.uk/tpru/BasilHiley/QuantEraserLight.pdf