Single-particle interference observed for macroscopic objects

[kvantti]

With a variation on the famous double-slit experiment of quantum mechanics, scientists Yves Couder and Emmanuel Fort from the University of Paris 7 are rewriting the textbooks. Their accomplishment, however, has less to do with quantum mechanics than with an observation once considered experimentally impossible: the wave-particle double nature of a macroscopic object (an oil droplet and its associated surface wave). The droplet, which is about 1mm (10 million times larger than an atom), is also one million times larger than the second largest object--a 2-nm molecule called a buckyball--whose wave-particle duality was observed in 2003.

http://www.physorg.com/news78650511.html

One millimeter oil droplets interfering with themselves... cool.
It looks like there doesn't seem to be an upper boundary size for quantum mechanical phenomenom.

 

[Careful]

http://www.physorg.com/news78650511.html

One millimeter oil droplets interfering with themselves... cool.
It looks like there doesn't seem to be an upper boundary size for quantum mechanical phenomenom.

On the contrary, the experiment shows that interference is very likely a CLASSICAL event (just as happens in Barut self field, the soliton travels through one slit but is influenced by its own wave). The authors moreover mention

``In our macroscopic experiment, even though we can observe the whole trajectory, we recover two features of the quantum mechanics experiments," Couder continued. "For one, the individual deviation of a given walker becomes uncertain because of the spatial limits imposed on its wave. Also, interference patterns are recovered in the statistics of successive individual events.''

This fits perfectly the Schrödinger (and de Broglie) picture about the meaning of the quantum wave.

``While the scientists observed that each droplet goes through only one slit, the associated wave travels through both slits, with the wave interferences determining the walker’s trajectory. ''

You can already start saying farewell to non locality. This is the best news for local realism in many years : it shows again that radiative phenomena are far from being understood. For those who did not get it : the waves in this experiment are REAL.

Careful

 

[kvantti]

On the contrary, the experiment shows that interference is very likely a CLASSICAL event (just as happens in Barut self field, the soliton travels through one slit but is influenced by its own wave).

Daaaamn, I didn't realize that... nice.

You can already start saying farewell to non locality. This is the best news for local realism in many years : it shows again that radiative phenomena are far from being understood. For those who did not get it : the waves in this experiment are REAL.

What are the local interpretations of QM besides the MWI? The Wikipedia article didn't give much info and I didn't find anything on google.

 

[Careful]

Daaaamn, I didn't realize that... nice.
What are the local interpretations of QM besides the MWI? The Wikipedia article didn't give much info and I didn't find anything on google.

The point is that this experiment strongly suggests that the wavefunction is just a statistical tool. The real single events obey nonlinear equations of motion where the nonlinearity originates from a self coupling to a radiation field (which hence also becomes nonlinear accounting for photon like effects). Therefore, it is meaningless to try to deduce a single event intepretation from the statistical entity, here the *apparant* non locality or consciousness nonsense enters the stage. As I also repeated on several occasions, the description of entanglement is incorrect too. So basically, this experiment severly overthrows the basic postulates of QM; as I said, you turned a bad day into a happy one for me. Again, the waves are real here, unlike in MWI.

Careful

 

[kvantti]

Again, the waves are real here, unlike in MWI.

Could you clarify? I've read that the waveform of a particle is fundamental in the MWI. Do you mean that it isn't?

 

[Careful]

Could you clarify? I've read that the waveform of the particle is fundamental in the MWI. Do you mean that it isn't?

Sure this is so for MWI. The point here is that this wave is a real LOCAL physical phenomenon due to particle oscillations; moreover this experiment strongly suggests that particles exist all the time, travel definite paths and so on. Moreover one can even follow the path here (which for electrons could also be possible for sufficiently sensitive apparati). So, no consciousness, no giving up of reality, locality ...
Well I have been playing around with the idea for some long time that the wave is due to oscillations of the internal particle degrees of freedom. For an electron, this is the case due to Zitterbewegung (see Barut). So, yes, I believe the wave to be a product of acceleration of matter degrees of freedom. This experiment for sure adds a lot of weight to this hypothesis. So what I say is that MWI is B.S.

Careful

 

[kvantti]

-- moreover this experiment strongly suggests that particles exist all the time, travel definite paths and so on. -- So what I say is that MWI is B.S.

Those aspects you mention are valid in the MWI. So how do you conclude that the MWI is BS? If anything the experiment shows that the Copenhagen interpretation is BS, atleast from my POV. Don't know then, maybe there's a hole in my knowledge or I just don't get your point. Anyway, I'm off to bed. See you (or read you ) tomorrow. Nighty night.

 

[Careful]

Those aspects you mention are valid in the MWI. So how do you conclude that the MWI is BS? If anything the experiment shows that the Copenhagen interpretation is BS, atleast from my POV. Don't know then, maybe there's a hole in my knowledge or I just don't get your point. Anyway, I'm off to bed. See you (or read you ) tomorrow. Nighty night.

HUH ? Not at all. In MWI, the particle does not have a definite deterministic trajectory, the wave is NOT a real physical entity : in this experiment the wave is observable *independent* of the extended particle The latter certainly contradicts ANY fashionable interpretation of QM (also BM as a matter of fact).


Careful

 

[selfAdjoint]

The point here is that this wave is a real LOCAL physical phenomenon due to particle oscillations

So spell it out. Is the wave due to zwitterbewegung or what in your interpretation?

(Added in edit) BTW, does your local realism, with its resemblances to soliton physics, comprise entanglement?.

 

[Careful]

So spell it out. Is the wave due to zwitterbewegung or what in your interpretation?

(Added in edit) BTW, does your local realism, with its resemblances to soliton physics, comprise entanglement?.

I answered both of your questions several times even just today. First, yes I believe the apparently non local one particle phenomena are due to back reaction effects - cfr. Barut self field. Second, entanglement as spelled out in the singlet state is physically incorrect (it does not require a genius to figure that out) and has never been experimentally confirmed : however it might be that the Bell inequalities are *seemingly* violated, I have hinted several times at negative probabilities in that context but I cannot say more about this right now. Another person who has some meaningful things to say about the Pauli exclusion principle is David Hestenes, you might ask CarlB for some references.

Careful

 

[RandallB]

I’m not so sure I see the big deal here.
They have a droplet of silicone oil on the “surface of a vibrating fluid”
This other fluid remains unidentified so are we suppose to forget this other fluid is there, a real form of aether?
Now the oil interacts with this surface to create a surface wave or “surface wave packet” on the surface of this other fluid.
Sorry I find this not to be a microscopic event, but a tiny example of a macroscopic event – analogous to a small boat going through one of two openings in a sea-wall to find itself affected by its own wave (created in and on that other fluid) coming through that other opening.

Sure it must be exciting to claim they have the largest microscopic event of duality. Exciting too to have local realist giving them great acclaims.
Don’t get me wrong, I’m as hungry for proof of locality as any one, but I’ll not be misled by a red herring; the buckyball is still the largest microscopic item to display true duality.
This drop of oil competes for the title of smallest macroscopic item to duplicate an effect seen with waves of water, adding little or nothing to the puzzle of entanglement.

Sorry to rain on anyones Happy Day parade.

 

[Careful]

I’m not so sure I see the big deal here.
They have a droplet of silicone oil on the “surface of a vibrating fluid”
This other fluid remains unidentified so are we suppose to forget this other fluid is there, a real form of aether?

I do not see any reason why the surface of this vibrating fluid is important regarding the selfinteraction effects. The fluidum in this case is just needed to support the drop, that is all.

Now the oil interacts with this surface to create a surface wave or “surface wave packet” on the surface of this other fluid.
Sorry I find this not to be a microscopic event, but a tiny example of a macroscopic event – analogous to a small boat going through one of two openings in a sea-wall to find itself affected by its own wave (created in and on that other fluid) coming through that other opening.

Sure, but you seem to have forgotten that for example Maxwell's theory has a hydrodynamic interpretation, that black hole models are currently investigated in the context of fluid dynamics and so on. Again, I do not see why the preexisting fluid is important in this context, only the vibration and self induced wave are. This is very clear in Barut Self field for example. But I agree that I do not find the claim in the communication grandiose, what I did find spectacular however was suggestion as if it was a macroscopic quantum event.

Sure it must be exciting to claim they have the largest microscopic event of duality. Exciting too to have local realist giving them great acclaims.
Don’t get me wrong, I’m as hungry for proof of locality as any one, but I’ll not be misled by a red herring; the buckyball is still the largest microscopic item to display true duality.
This drop of oil competes for the title of smallest macroscopic item to duplicate an effect seen with waves of water, adding little or nothing to the puzzle of entanglement.

Entanglement is incorrect, Bell inequality violation could occur.


**
Sorry to rain on anyones Happy Day parade. **

Oh not at all, I was just amused by the fact that some people seem to be surprised by such phenomenon.

 

[Farsight]

Careful, are you saying that the Dual Slit experiment has had all the QM guys wasting their time for years with MWI and other postulates because it's all here with a bit of oil and wavy water, dead easy to understand?

 

[Careful]

Careful, are you saying that the Dual Slit experiment has had all the QM guys wasting their time for years with MWI and other postulates because it's all here with a bit of oil and wavy water, dead easy to understand?

Well, although the picture is much easier to understand, the mathematics behind it is less trivial since the equation involved is a non linear integro-differential equation. So yes, all the ``spookyness'' and fuzzy ontology of quantum mechanics (for single particle statistics) comes from treating a non linear problem (in which seemingly non local phenomena can occur) as a linear one. I refer again to A.O. Barut ``combining relativity and quantum mechanics : Schrödinger's interpretation''. By the way, let me tell you that such interpretation had been suggested by Schrödinger in the 1920 ties, but his calculations were rather problematic since he tried this self coupled idea for spin 0 particles (in either complex KG equation). This lead him to an unstable system (the charge distributions just exploded) which seemingly made his program impossible. However, Barut has reinvestigated the same idea but now with Dirac's spinor equation and the resulting system is stable (and gives all QED effects such as Lamb shift, gyromagnetic factor, casimir effect, vacuum polarization ...) due to the internal electron motion (so Zitterbewegung) as far as I understand it. In the above paper he also mentions why the nonlinearity is crucial in explaining the double slit experiment from a local perspective. So please, don't be so surprised, what I am saying is far from ``radical'' - in that regard it does not seem difficult at all to explain interference in the Buckyball (the very symmetric form of this molecule makes one suspect that the selfinterference pattern is constructive rather than destructive). Now, suppose you learn that all these cherished effects are just ``classical'' and nonlinear, how would this reflect on considerations towards ``entanglement'' you think ?? Remember that the latter was a dirty word 35 years ago.

Careful

 

[Farsight]

Thanks Careful. Food for thought.

 

[kvantti]

what I did find spectacular however was suggestion as if it was a macroscopic quantum event.

If you're referring to my statement, I must apologize. I don't speak english as my native language and I may (and obviously) have made a hasty conclusion. I just got so excited about the topic that I rushed to make a thread about it after reading some of it.

Either way, it sure gives some direction to the nature of quantum interference. I see it as supporting the view of the MWI; others see it differently.

HUH ? Not at all. In MWI, the particle does not have a definite deterministic trajectory, the wave is NOT a real physical entity : in this experiment the wave is observable *independent* of the extended particle --

Umm, if the particles are localized and "exist all the time", as in the MWI, doesn't this mean they have definite trajectories aswel? The trajectory of a particle in one universe is influenced by its counterparts in other universes because of interference. So even tho the particle goes thru only one slit in our universe, its trajectory is still affected by its counterparts, aslong as the universes don't decohere.

I see this analogous to the experiment with the oildroplet. Even tho the droplet goes thru only one slit, the wave passes thru both slits and therefore affects the droplets trajectory. Similiarly, a particle goes thru only one slit in our universe, while its counterparts in other universes go thru both slits, enabling the particle to "interfere with itself" and affect the trajectory of the particle (in every universe the experiment is performed).

Heres a couple of papers about locality:
http://lanl.arxiv.org/abs/quant-ph/9906007
http://lanl.arxiv.org/abs/quant-ph/0003146

 

[Careful]

If you're referring to my statement, I must apologize. I don't speak english as my native language and I may (and obviously) have made a hasty conclusion. I just got so excited about the topic that I rushed to make a thread about it after reading some of it.

Oh, no problem, I like its topic

Either way, it sure gives some direction to the nature of quantum interference. I see it as supporting the view of the MWI; others see it differently.

Then I can only conclude that you did not understand anything about my remarks concerning the *independent* reality of the wave.

Umm, if the particles are localized and "exist all the time", as in the MWI, doesn't this mean they have definite trajectories aswel? The trajectory of a particle in one universe is influenced by its counterparts in other universes because of interference. So even tho the particle goes thru only one slit in our universe, its trajectory is still affected by its counterparts, aslong as the universes don't decohere.

Knock, knock the wave is a physical thingie measured independently of the oil drop that is what kills of MWI (moreover, everyone in the lab *consciously* agrees that it goes through the same slit ). Hence, this invalidates all the rest you say...

PS: do not throw papers about ``locality'' to me, I know very well what locality means and I do not need some crackpot consciousness proponents (that is Deutsch) to lecture me about it.

Careful

 

[Farsight]

Ah. David Deutsche. Not German.

 

[Careful]

Ah. David Deutsche. Not German.

No, no Deutsch, it is written like that in the arxiv.

 

[kvantti]

Then I can only conclude that you did not understand anything about my remarks concerning the *independent* reality of the wave.

Knock, knock the wave is a physical thingie measured independently of the oil drop that is what kills of MWI (moreover, everyone in the lab *consciously* agrees that it goes through the same slit ). Hence, this invalidates all the rest you say...

But the wave isn't quantum mechanical. As I said, "I see it analogous..."

PS: do not throw papers about ``locality'' to me, I know very well what locality means and I do not need some crackpot consciousness proponents (that is Deutsch) to lecture me about it.

The MWI has nothing to do with consciousness. The Copenhagen interpretation deals with the consciousness mumbo jumbo.

 

[Careful]

But the wave isn't quantum mechanical. As I said, "I see it analogous..."

Sigh, so how do you explain then in detail in your QM, that
(a) the particle can be observed all the time without disturbing the system (ok MWI could do that)
(b) why it is that it is the physical wave produced by the oscillating particle which forces the latter to reproduce the interference pattern after repeated events ?

You reproduce QM results here without (a) using QM, (b) giving up locality, reality etc...

So, basic common sense suggests that in the microworld exactly the same mechanism does the trick. QM says exactly ZIP about internal degrees of freedom causing a radiation backreaction process in the explanation of the double slit experiment. On the contrary the wave was exactly IMPORTED just to ``explain'' this result. Hence, Occam's raisor does the rest.

The MWI has nothing to do with consciousness. The Copenhagen interpretation deals with the consciousness mumbo jumbo.

You must come from another universe because every elementary textbook in this one explains the necessity of conscious perception for MWI to work.

Careful

 

[kvantti]

So, basic common sense suggests that in the microworld exactly the same mechanism does the trick.

I wouldn't trust common sense so much... but that's just me.
How would you interpret QM from the point of view you suggest?

You must come from another universe because every elementary textbook in this one explains the necessity of conscious perception for MWI to work.

Any references? I find this hard to believe. All you need in MWI is decoherence. Sure, if you want to know if the system is decohered you need to "consciously check it", but I see nothing more to it. The MWI works just fine without conscious observers.

 

[Careful]

I wouldn't trust common sense so much... but that's just me.
How would you interpret QM from the point of view you suggest?

As a statistical tool which gives the wrong *description* for what is supposed to happen. You apparently don't get it that I do not think of QM as fundamental theory.

Any references? I find this hard to believe. All you need in MWI is decoherence. Sure, if you want to know if the system is decohered you need to "consciously check it", but I see nothing more to it. The MWI works just fine without conscious observers.

Huh, the very difference between decoherence and MWI is that you live only in one universe and you do not need the rest of it to decohere your pointer states, a trick which does not work for closed systems by the way. And still you did not define what this conscious check is : you are merely adding words to shift the same problem to another level (that is : you need a classical check in a quantum system).

But the upshot of your argument is that you can in principle save your ass (which I admit) but in a system which is much more complicated than the realistic setup (and which nobody calculated up till now). It is like saying that Newton is not to be trusted because you can fit the data with adding epicycles. Great, you cannot even recognize the absurdity of an argument when a much better explanation can be proven to do the job. That is the message of Occam's raisor which too many have forgotten.

Careful

 

[RandallB]

I do not see any reason why the surface of this vibrating fluid is important regarding the selfinteraction effects. The fluidum in this case is just needed to support the drop, that is all.

amused by the fact that some people seem to be surprised by such phenomenon.

Of course the fluid makes a difference; you cannot legitimately call the oil drop making waves in a fluid and then being later being affected by that wave a “self interaction effect”! No more than a can claim be made for the boat being affected by water waves that were originally created by that same boat a “self interaction effect”.

There is nothing here that did not already exist with the example of the boat on a larger scale.
Although I’m convinced both entanglement and QM are wrong; there is no proof here to justify declaring them wrong.

I’m not amused; but disappointed by those that are willing to trick themselves into accepting as proof what amounts to the misdirection of a magician’s parlor trick, in this case fooling even the magician.

 

[rlduncan]

Although I’m convinced both entanglement and QM are wrong; there is no proof here to justify declaring them wrong.

What would it take to show QM is wrong? If this is a "real wave", would a real wave solution to the SE equation be sufficient?

 

[Farsight]

I’m not amused; but disappointed by those that are willing to trick themselves into accepting as proof what amounts to the misdirection of a magician’s parlor trick...

I don't accept it as proof Randall. But on the other hand I'm feeling a little cagey about just who's been doing the parlor tricks.

 

[Careful]

Of course the fluid makes a difference; you cannot legitimately call the oil drop making waves in a fluid and then being later being affected by that wave a “self interaction effect”! No more than a can claim be made for the boat being affected by water waves that were originally created by that same boat a “self interaction effect”.

The authors in the paper clearly write that only at a critical frequency a wave is emitted from the oil drop : you seem to forget that the oil drop is simply vibrating with the fluidum. So any extra effect must be a self interaction effect. Now, you could say that at some critical frequency the oil and fluid are going to vibrate differenty because of density differences and finite extension of the drop and that this might produce the wave. True, but it seems to me that this problem is equivalent to vibrating internal degrees of freedom producing the wave motion of the oil drop. A boat is only producing waves at its tale which are not interfering with its own motion at all, neither is it simply floating on the surface of water. Moreover, you seem again to ignore that electromagnetism -although the waves move through the vacuum- has a hydrodynamical interpretation. Now any particle in nature couples to a (non abelian) gauge field ... you can make the further deduction.

There is nothing here that did not already exist with the example of the boat on a larger scale.
Although I’m convinced both entanglement and QM are wrong; there is no proof here to justify declaring them wrong.

Again, the boat produces only waves traveling opposite to its motion and there is no reason to take the part played by the fluidum seriously (see Holland about electromagnetism). Moreover, there is no proof to declare entanglement correct : there is just a naive theory which is not falsified after some systematic, substantial data substractions and noise corrections.

I’m not amused; but disappointed by those that are willing to trick themselves into accepting as proof what amounts to the misdirection of a magician’s parlor trick, in this case fooling even the magician.

You did not offer any substantial comments to what I said, neither do I think you are aware of either Barut's work, nor the hydrodynamical interpretation of EM.

Careful

 

[RandallB]

you seem to forget that the oil drop is simply vibrating with the fluidum. So any extra effect must be a self interaction effect.

You lose lots a of credibility with me when you restate their words to suit your own needs as to what must be. (part of fooling yourself?)
Not vibrating with; They said the drop was bouncing on the fluid and they even said the "bouncing drop could ‘surf’ ". But they decline to offer any evidence that the wave it surfs on was not a wave in the fluid. They simple assume and claim the wave, whatever it is, should be assumed to be part of the oil not the fluid.
I don't buy it - how about something simple like conservation of momentum and the falling drop turning around and going up instead of down. Is it not fair to expect a comment on how that momentum change should be expected to be seen in waves in and of the fluid? Or is it to much to expect to retain use of such laws of physics here?

As to how a boat works you need to calm down, actually get out in the real world on some nice smooth calm relaxing water. Find a seawall with a seawall with a couple opining and just "rock the baby" as you slowly move through one.

And on changing the subject of the thread; I have no comments for an "interpretation" that ultimately depends on a mathematical foundation equivalent to an aether. I don't take the bait to waste my time chasing such a canard. Save us the time and misdirection if you had something you could simple "Take me to your Aether". Otherwise I've no reason to think it might be the Real Deal.
You still don't get it do you, I'll not be satisfied with an "interpretation" that I can fool myself with like so many do. I expect to find the real deal, and I don't expect those committed to a non-local (QM, BM, MWI, Strings, M, etc.) theory; to accept my opinion on local realism just because of some contrived "interpretation". They expect an explanation that is the real deal, therefore so must I.

That said you may have your way here, I see no further point in continuing this thread, I'll unsubscribe and leave it to you. This has been a long enough for a wild goose chase

 

[Careful]

You lose lots a of credibility with me when you restate their words to suit your own needs as to what must be. (part of fooling yourself?)

Haha, if you see citations in this respect then everyone I know of on this website is fooling himself. Take care, this paper will be peer reviewed

Not vibrating with; They said the drop was bouncing on the fluid and they even said the "bouncing drop could ‘surf’ ". But they decline to offer any evidence that the wave it surfs on was not a wave in the fluid. They simple assume and claim the wave, whatever it is, should be assumed to be part of the oil not the fluid.

True, now go back at the double slit experiment, manifest the same critical attitude and tell us then for what good reason we should believe in wave particle duality if an alternative explanation in terms of nonlinear self interaction is available.

I don't buy it - how about something simple like conservation of momentum and the falling drop turning around and going up instead of down. Is it not fair to expect a comment on how that momentum change should be expected to be seen in waves in and of the fluid?

Good question ! Now, take an electron with its internal motion (zitterbewegung), clearly energy momentum is not conserved here (since we have to tune on an EM field to account for the self interactions), so what you get from the coupled Dirac Maxwell system is that this results in soliton like solutions which can feel their own interference pattern. Now take the bouncing oil drop as one entity, then what this experiment shows is that the induced motion has all the right properties : whether this wave now ``results'' from the oil or from the water is irrelevant since in gauge interactions I know the sea is there once the particle is. That is why I referred you to the hydrodynamical interpretation of EM, this is just not some cheap trick of mine, there simply never is a ``single particle'', a mistake which is too often made.

You still don't get it do you, I'll not be satisfied with an "interpretation" that I can fool myself with like so many do. I expect to find the real deal, and I don't expect those committed to a non-local (QM, BM, MWI, Strings, M, etc.) theory; to accept my opinion on local realism just because of some contrived "interpretation". They expect an explanation that is the real deal, therefore so must I.

I think you are confused on several points here
(a) I do not do in eather - think about the points I raised before, Barut self field has nothing to do with eather whatsoever. On the contrary, it bans vacuum fluctuations. In that theory, it (the particle nature of the wave) is a genuine self induced effect.
(b) most people do not even know what the real deal is, as I said before, the lack of bare date of EPR experiments does obscure what the problem is severely.
(c) what some people ask is unreasonable : I pointed out that any but entanglement effects are most likely ``classical'', now it has come so far that you have to reproduce something which has never been observed... or that you have to reproduce these quantum effects even if you have shown previous similar assertions to fail.

Of course, I admit that this experiment is not ``conclusive'', but at least it is hinting at other more reasonable possibilities (which were already long known by local realists).

Careful