Wave-particle duality at Macro scale?


by bohm2
Tags: duality, macro, scale, waveparticle
audioloop
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#19
Sep16-12, 09:50 AM
P: 461
Quote Quote by my_wan View Post
I figured I was off in my characterization of your contradiction. Which is why I asked before making a guess. However, you didn't explain what contradiction you intended with this response?

First off Spekkens never abrogated operationalism, nor its negation. To say some principle does not "forces" us into operationalism is not an abrogation of operationalism. Operationalism fully retains its "usefulness" irrespective of whether we entirely restrict ourselves to it or not. neither does admitting the "usefulness" of operationalism downplay the claim that theoretical constructs are not required to be strictly operational descriptions.

I guess what I really need is a better explanation of exactly how you think he may have contradicted himself?
you did, not me......
my_wan
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#20
Sep16-12, 03:37 PM
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Apparently you don't want to answer the question. Nor does the above quote make any sense.
audioloop
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#21
Sep16-12, 04:38 PM
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Quote Quote by my_wan View Post
Nor does the above quote make any sense.
A lot of sense, you attribute to me, things I have not done, but you do not become aware...
see below

Quote Quote by my_wan View Post
Spekkens, from your quote, said: "...Such a principle does not us into operationalism,... To which you responded to me pointing out the use of the term "force" with: "is abrogate a method and later downplay it".
i answered, what ?!
the term FORCE with quotations marks ?
where !!! i answered that ?
pointing out ?!!! what ?!
no way, re-read the posts and you will see....


read your post 17 and you will see your mistake.
my_wan
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#22
Sep16-12, 09:23 PM
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Quote Quote by audioloop View Post
A lot of sense, you attribute to me, things I have not done, but you do not become aware...
see below
Yeah, I accepted that. But I asked for clarification which you never provided.



i answered, what ?!
The problem is you never did answer.


the term FORCE with quotations marks ?
I put the word "force" in quotations before it was a quote of Spekkens, not you. I even requoted Spekkens and put the word "force" in red so you would know what it referred to.


where !!! i answered that ?
pointing out ?!!! what ?!
no way, re-read the posts and you will see....
How can I see when you still haven't answered my question.

read your post 17 and you will see your mistake.
Post #17 was the one where I admitted my characterization was probably wrong.
Quote Quote by my_wan View Post
I figured I was off in my characterization of your contradiction. Which is why I asked before making a guess. However, you didn't explain what contradiction you intended with this response?
Yet you still have not answered.

Answer this one question:
What contradiction was you referring to in post #13?
Repeat:
What contradiction was you referring to in post #13?
Repeat:
What contradiction was you referring to in post #13?
Hernik
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#23
Sep19-12, 04:27 PM
P: 90
Love these links you throw at us, Bohm2 :-)

But: I'm trying to understand this in a intuitive way as I lack the mathematical insight.

I have two questions regarding the link form an earlier post by Bohm2, november 2011:

Beyond the Quantum by Valentini:
http://arxiv.org/PS_cache/arxiv/pdf/...001.2758v1.pdf

On top of page 6, Valentini writes about the fate of The Pilot Wave Theory on the 1927 Solway conference: "de Broglie seems not to have recognized that his dynamics was irreducibly non-
local. Nor was this recognized by anyone else at the conference. The action of
the wave in multidimensional configuration space is such that a local operation
on one particle can have an instantaneous effect on the motions of other (distant)
particles."

Why is the Pilot Wave Theory irreducibly non-local - which aspect of the theory predicts that entangled particles react to each other instantly, disregarding relativity? Can someone please try to explain that to me... in plain english if possible? (It's a classical description of quantum mechanics, so we can start visualising things again, right?)

AND from that same link page 7, line 4:

"Bell made it clear that the pilot wave is a ‘real objective field’ in configuration
space, and not merely a mathematical object or probability wave."

I'm having trouble understanding/picturing what is meant by "configuration space" and a "wave in multidimensional configuration space". Would it be approximately right to think of this wave in configuration space as the wave of each particle existing in it's own space-time interacting with all other particles waves in their space-times... or more dramatic: "The particle's universal wave up against the United Universal Waves of The Universe" ("United Space" for short :-)?

Hope someone can help me to understand this better - I find it very interesting.

Best, Henrik
bohm2
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#24
Sep20-12, 09:08 AM
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Quote Quote by Hernik View Post
I'm having trouble understanding/picturing what is meant by "configuration space" and a "wave in multidimensional configuration space".
Not sure if this is what you are looking for or if you've already read the links in that thread but I started a thread on the topic wth many intoductory links on the topic. You might find the papers in that thread very interesting and they're pretty descriptive/more philosophical:

The reality of configuration space
http://www.physicsforums.com/showthread.php?t=554543
eloheim
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#25
Oct5-12, 07:37 AM
P: 65
Just to echo Hernik, thanks for your efforts here, bohm. Once again I've got plenty of new homework waiting for me!
bohm2
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#26
Oct9-12, 10:15 PM
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This is another interesting paper that recently came out by Y. Couder et al. They discuss the 2 different models proposed by Bohm versus de Broglie's theory of the Double Solution with reference to the diffraction of bouncing droplets:
As a result the wave field is the linear superposition of the successive Faraday waves emitted by past bounces. Its complex interference structure thus contains a memory of the recent trajectory. Furthermore, since the travelling waves move faster than the drop, the wave field also contains information about the obstacles that lie ahead. Hence, two non-local effects exist in the wave-field driving the motion of the droplet: the past bounces influence directly the present (direct propulsion) and the trajectory is perturbed by scattered waves from distant obstacles in a kind of echo-location effect. This interplay between the droplet motion and its associated wave field makes it a macroscopic implementation of a pilot-wave dynamics.
Probabilities and trajectories in a classical wave-particle duality
http://iopscience.iop.org/1742-6596/...1_1_012001.pdf
harrylin
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#27
Oct10-12, 05:38 AM
P: 3,178
Quote Quote by bohm2 View Post
This is another interesting paper that recently came out by Y. Couder et al. They discuss the 2 different models proposed by Bohm versus de Broglie's theory of the Double Solution with reference to the diffraction of bouncing droplets:

Probabilities and trajectories in a classical wave-particle duality
http://iopscience.iop.org/1742-6596/...1_1_012001.pdf
I had overlooked this thread - very interesting, thanks!
Hernik
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#28
Oct11-12, 05:12 PM
P: 90
"Probabilities and trajectories in a classical wave-particle duality
http://iopscience.iop.org/1742-6596/...1_1_012001.pdf"

That was great fun to read, bohm2. Adding the memory of the pilot wave to the explanation of how pilot waves function is the first time in more than 80 years that someone expands de Broglie's dual pilot wave theory, isn't it?

I have a question though: In a passage on the middle of page 4, Couder is describing the result of his diffraction experiment with walkers: "This means that the probability distribution of the deviations of a droplet is given by the
diffraction of a plane wave . This result is similar to what would be obtained with electrons
or photons except that the distribution would then be given by the square of the wave amplitude."

"Similar ... except" What does he mean - is it similar or is it different? Can it be both? So that the result given by a plane wave in two dimensions is directly comparable to a distribution given by the square of the amplitude of a wave in three dimensions - is that the way it should be understood?

Best, Henrik
bohm2
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#29
Oct11-12, 07:07 PM
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Just to add to the links in case anybody is as fascinated by these experiments as I am I thought I would also post the experiment simulating the Zeeman effect by this same group of physicists:
Physicists in France have used pairs of bouncing droplets on a fluid surface to simulate the Zeeman effect – a phenomenon that played an important role in the early development of quantum mechanics. The ability to simulate purely quantum effects using such a classical system could provide insight into how the mathematics of quantum mechanics should be interpreted.
Level splitting at macroscopic scale
http://stilton.tnw.utwente.nl/people...ted/Zeeman.pdf

Bouncing droplets simulate Zeeman effect
http://physicsworld.com/cws/article/...-zeeman-effect
Quote Quote by Hernik View Post
"Similar ... except" What does he mean - is it similar or is it different? Can it be both? So that the result given by a plane wave in two dimensions is directly comparable to a distribution given by the square of the amplitude of a wave in three dimensions - is that the way it should be understood?
If I'm understanding this (I might not be), I think Jarek in the second link offers a suggestion on that question:
The counterargument is the Bell inequality - the consequence of the squares relating amplitudes and probabilities ... but the same squares appear while we make statistical physics properly (Maximal Entropy Random Walk) - in statistical ensemble of trajectories, amplitudes are probabilities on the end of ensembles of half-trajectories toward past or future and to get probability of getting something in constant time cut, we need to get it from both past and future: multiply both amplitudes.
Hernik
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#30
Oct12-12, 03:14 PM
P: 90
The counterargument is the Bell inequality - the consequence of the squares relating amplitudes and probabilities ... but the same squares appear while we make statistical physics properly (Maximal Entropy Random Walk) - in statistical ensemble of trajectories, amplitudes are probabilities on the end of ensembles of half-trajectories toward past or future and to get probability of getting something in constant time cut, we need to get it from both past and future: multiply both amplitudes.

Well. I certainly cannot say I understand Jareks words to any depth :-). But it leaves me with the impression/hunch that the plane wave in two dimensions IS directly comparable to the three dimensional wave IF the latter represents a probability distribution and not a physical wave - is that a reasonable interpretation of Jareks comment? Jarek?

Best, Henrik
bohm2
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#31
Oct12-12, 09:39 PM
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I'm guessing English isn't his first language but it reads better in the link of his article he cites:
There are also essential differences, mainly similar to Nelson’s interpretation, motivation is resemblance to quantum mechanics and that instead of standard evolution there is used so called Bernstein process: situation in both past and future (simultaneously) is used to find the current probability density...Abstract ensembles of four-dimensional scenarios also bring natural intuition about Born rule: the squares relating amplitudes and probabilities while focusing on constant-time cut of such ensemble. In given moment, there meets past and future half-paths of abstract scenarios we consider-we will see that the lowest energy eigenvector of Hamiltonian (amplitude) is the probability density on the end of separate one of these past or future ensembles of half paths. Now the probability of being in given point in that moment is probability of reaching it from the past ensemble, multiplied by the same value for the ensemble of future scenarios we consider-is the square of amplitude.
From Maximal Entropy Random Walk to quantum thermodynamics
http://arxiv.org/pdf/1111.2253v3.pdf

I also found this comment by Jarek discussing deBroglie model analogue of the external vibration frequency induced by Couder group interesting:
Much less problematic view was started by de Broglie in his doctoral paper: that with particle’s energy (E = mc2), there should come some internal periodic process (E = ~hω) and so periodically created waves around - adding wave nature to this particle, so that it has simultaneously both of them. Such internal clock is also expected by Dirac equation as Zitterbewegung (trembling motion). Recently it was observed by Gouanere as increased absorbtion of 81MeV electrons, while this "clock" synchronizes with regular structure of the barrier. Similar interpretation of wave-particle duality (using external clock instead), was recently used by group of Couder to simulate quantum phenomena with macroscopic classical objects: droplets on vibrating liquid surface.The fact that they are coupled with waves they create, allowed to observe interference in statistical pattern of double slit experiment, analogue of tunneling: that behavior depends in complicated way on the history stored in the field and finally quantization of orbits- that to find a resonance with the field, while making an orbit, the clock needs to make an integer number of periods.
Hernik
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#32
Oct14-12, 07:22 PM
P: 90
Quote Quote by bohm2 View Post
A very interesting lecture presentation (~ 83 minutes) from Perimeter by Yves Couder:

A Macroscopic-scale Wave-particle Duality : the Role of a Wave Mediated Path Memory
http://pirsa.org/displayFlash.php?id=11100119
I re-viewed the link.

From 70.10

...Couder is talking about deBroglie’s idea of two waves in quantum mechanics : A standing wave surrounding the particle, and a wave representing probabilities, namely the Schrödinger wave. Couder then compares this idea to the experiments with walkers passing through a slit the size of the wavelength of the standing wave generated by the droplet:

“So in fact if you reconsider our experiment: In a way it suggests a sort of implementation of de Brogle’s idea. Because if you look at one trajectory of our wave/particle association, when you look at the passage of.. at this thing passing through the slit. You have a real particle associated with a standing wave that moves through the slit and doesn’t look at all like it is a plane wave.
But if you look at the statistics, then you will see, that the statistics look, as if you had had a plane wave crossing the slit, so in a way (...) this would be the schrödinger wave.”

So I think I can answer my “similar...except”-question: The distribution of the directions of the droplets in Couder’s experiment with walkers going through slits is similar to the Schrödinger equation in the way that it is simply a probability distribution (due to the wavefronts merging after the slit after the droplet has achieved a random direction during the passing of the slit)- reflecting what Bohr convinced Schrödinger about during his famous visit in Copenhagen.

So IF Couder’s group’s experiments are valid analogies to what goes on at the quantum scale, the experiments not only support de Broglie’s ideas of two types of waves (real standing waves AND a probability-wave) at play in quantum mechanics, but also justify the Copenhagen people’s idea of a genuine randomness at play after a measurement, as well as give enormous credit to Einstein’s view that if it is part of this world it’s gotta behave classically + it contradicts Bohm’s idea of the Schrödinger wave being physical?

Best, Henrik
bohm2
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#33
Oct14-12, 09:20 PM
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Quote Quote by Hernik View Post
So IF Couder’s group’s experiments are valid analogies to what goes on at the quantum scale, the experiments not only support de Broglie’s ideas of two types of waves (real standing waves AND a probability-wave) at play in quantum mechanics, but also justify the Copenhagen people’s idea of a genuine randomness at play after a measurement, as well as give enormous credit to Einstein’s view that if it is part of this world it’s gotta behave classically + it contradicts Bohm’s idea of the Schrödinger wave being physical?
I have trouble reconciling these differences. On the one hand, I assumed that the PBR no-go theorem (with some assumptions) requires that the Schodinger wave be ontic. Furthermore, statistical trajectories conforming to the Bohmian trajectories have been observed experimentally. With respect to the trajectories of single particles in Couder's experiments versus Bohmian, note that the Bohmian trajectories obey the "no crossing rule" which are consistent with experiments unlike Couder's. As Couder writes:
Another difference is that the Bohmian trajectories do not cross the symmetry axis of the system. Those passing on the left (right) of the slits are always deviated to the left (right). This can be seen as a characteristic difference between the Bohmian trajectory that concerns a probability density and the individual trajectory of a single particle.
Grossing et al. have modeled a Couder-type system that does actually respect the "no crossing" rule:
To account for this context, we introduce a "path excitation field", which derives from the thermodynamics of the zero-point vacuum and which represents all possible paths a "particle" can take via thermal path fluctuations. The intensity distribution on a screen behind a double slit is calculated, as well as the corresponding trajectories and the probability density current. The trajectories are shown to obey a "no crossing" rule with respect to the central line, i.e., between the two slits and orthogonal to their connecting line. This agrees with the Bohmian interpretation, but appears here without the necessity of invoking the quantum potential.
They go on to argue for an advantage of their model over Bohmian:
To fully appreciate this surprising characteristic, we remind the reader of the severe criticism of Bohmian trajectories as put forward by Scully and others.The critics claimed that Bohmian trajectories would have to be described as "surreal" ones because of their apparent violation of momentum conservation. In fact, due to the "no crossing" rule for Bohmian trajectories in Young's double slit experiment, for example, the particles coming from, say, the right slit (and expected at the left part of the screen if momentum conservation should hold on the corresponding macro-level) actually arrive at the right part of the screen (and vice versa for the other slit). In Bohmian theory, this "no crossing" rule is due to the action of the non-classical quantum potential, such that, once the existence of a quantum potential is accepted, no contradiction arises and the trajectories may be considered "real" instead of "surreal". Here we can note that in our sub-quantum approach an explanation of the "no crossing" rule is even more straightforward and actually a consequence of a detailed microscopic momentum conservation. As can be seen in Fig. 1, the (Bohmian) trajectories are repelled from the central symmetry line. However, in our case this is only implicitly due to a "quantum potential", but actually due to the identification of the latter with a kinetic (rather than a potential) energy: As has already been stressed in [15], it is the "heat of the compressed vacuum" that accumulates along said symmetry line (i.e., as reservoir of "outward" oriented kinetic energy) and therefore repels the trajectories. Fig. 1 is in full concordance with the Bohmian interpretation (see, for example, [24] for comparison). However, as mentioned, in our case also a "micro-causal" explanation is provided, which brings the whole process into perfect agreement with momentum conservation on a more "microscopic" level.
An explanation of interference effects in the double slit experiment: Classical trajectories plus ballistic diffusion caused by zero-point fluctuations
http://arxiv.org/pdf/1106.5994v3.pdf

A more philosophical paper and slides by Grossing discussing these ideas can be found here:

The Quantum as an Emergent System
http://www.nonlinearstudies.at/files/ggEmerQuM.pdf
http://iopscience.iop.org/1742-6596/...1_1_012008.pdf
bohm2
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#34
Oct16-12, 09:15 PM
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From the Gerhard Grossing et al. paper in the previous link above the authors mentioned a fortcoming paper to explain entanglement/wholeness/non-locality using analogies/insights from the Couder classical "walking" bouncer experiments:
We shall show in a forthcoming paper how this feature of "wholeness" implies the existence of nonlocal correlations. Due to the nonlocal nature of the involved diffusion wave fields, and based on our proposed model, it should be possible to prove a corresponding identity with entangled states in quantum mechanics.
This paper was just posted today:
This, at least, is what we want to propose here, i.e., that there are further insights to be gained from the experiments of Couder's group, which could analogously be transferred into the modeling of quantum behavior. Concretely, we do believe that also an understanding of nonlocality and entanglement can profitt from the study of said experiments. In fact, one indispensable prerequisite for these experiments to work, one basic commonality of all of them, is that the bath is vibrating itself...
A Classical Framework for Nonlocality and Entanglement
http://lanl.arxiv.org/pdf/1210.4406.pdf
pilotwave
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#35
Dec30-12, 04:18 AM
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There are some new results from the walking droplets that demonstrate how wave-like statistics arise from an underlying pilot-wave dynamics through deterministic chaos.

http://www.youtube.com/watch?v=nmC0ygr08tE

What do you think?
bohm2
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#36
Dec30-12, 12:18 PM
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Quote Quote by pilotwave View Post
There are some new results from the walking droplets that demonstrate how wave-like statistics arise from an underlying pilot-wave dynamics through deterministic chaos.

http://www.youtube.com/watch?v=nmC0ygr08tE

What do you think?
The video is summarizing most of the stuff linked above. But what is the microscopic equivalent to the vibrating bath seen in droplet experiments? I've come across papers suggesting some form of "intrinsic periodicity" as per de Brogle's idea suggesting that inside the particle there was a periodic process that was equivalent to a clock. Donatello Dolce has published a few papers on this topic, but I haven't seen it much discussed elsewhere:
We interpret the relativistic quantum behavior of elementary particles in terms of elementary cycles. This represents a generalization of the de Broglie hypothesis of intrinsically “periodic phenomenon”, also known as “de Broglie internal clock”. Similarly to a “particle in a box” or to a “vibrating string”, the constraint of intrinsic periodicity represents a semi-classical quantization condition, with remarkable formal correspondence to ordinary relativistic quantum mechanics. In this formalism the retarded local variations of four-momentum characterizing relativistic interactions can be equivalently expressed in terms of retarded local modulations of de Broglie space-time periodicity, revealing a geometrodynamical nature of gauge interaction.
On the intrinsically cyclic nature of space-time in elementary particles
http://arxiv.org/pdf/1206.1140.pdf


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