What are the implications of this experiment?

[Demystifier]

Let me put some doubts on all this "interpretation" business. What is the point of interpretation? Isn't it a waste of time to discuss on these purely philosophical "ontology" questions?

Thinking about interpretations may inspire research resulting in more concrete results. For example, thinking about the Bohmian interpretation inspired Bell to find Bell inequalities. Similarly, thinking about many worlds inspired Deutsch to make concrete results on quantum computers. Or thinking about the meaning of wave-particle duality inspired delayed-choice experiments. Even Feynman path integrals was inspired by Feynman's philosophical thoughts on quantum ontology. Etc, etc ...

The minimal statistical interpretation you prefer is too sterile to inspire such innovative ways of thinking about QM. This sterile interpretation is sufficient for those who only want to make routine calculations in conceptually already understood domains of quantum physics, but not for those who attempt to be more creative.

 

[Varon]

Thinking about interpretations may inspire research resulting in more concrete results. For example, thinking about the Bohmian interpretation inspired Bell to find Bell inequalities. Similarly, thinking about many worlds inspired Deutsch to make concrete results on quantum computers. Or thinking about the meaning of wave-particle duality inspired delayed-choice experiments. Even Feynman path integrals was inspired by Feynman's philosophical thoughts on quantum ontology. Etc, etc ...

The minimal statistical interpretation you prefer is too sterile to inspire such innovative ways of thinking about QM. This sterile interpretation is sufficient for those who only want to make routine calculations in conceptually already understood domains of quantum physics, but not for those who attempt to be more creative.

Also note that the correct interpretation would produce an emergence that won't be found in the incorrect interpretations. It's like the correct understanding of atomic theory has led to superconductivity. Without understanding electron wave functions. We won't know how cooper pairs behave. Superconductivity is an emergence. This is also true for the correct interpretation which would produce a breakthrough as stunning as the birth of the quantum in year 1900. In fact I think that it is within a decade that we would see its arrival. That is why we have to accelerate quantum understanding and also cooperation with other groups that can give clues to what form it may take.

 

[Phrak]

Where is the original research article, rather than just internet sites jaw-boning about it third hand--like this one?

 

[Demystifier]

Where is the original research article, rather than just internet sites jaw-boning about it third hand--like this one?

http://www.sciencemag.org/content/332/6034/1170.full

 

[Demystifier]

The minimal statistical interpretation you prefer is too sterile to inspire such innovative ways of thinking about QM. This sterile interpretation is sufficient for those who only want to make routine calculations in conceptually already understood domains of quantum physics, but not for those who attempt to be more creative.

Vanhees, in the meanwile I have seen that you are doing particle physics phenomenology, and that you are doing it very well. I was not surprised at all, because phenomenology is exactly the kind of physics where minimal statistical interpretation is sufficient. But contrary to what most phenomenologists think, physics is not only phenomenology. For example, Feynman would never discover path integrals (now very useful in particle phenomenology) if he didn't think about ontological questions as well.

 

[Varon]

Here's the reason why ontology is very important. And one can follow it by logic. We know qualia or internal subjective experience is not part of our physics as Demystifier has emphasized before. So how is qualia related to matter (our brain). The right interpretation would offer the interface of how qualia is coupled to brain! This is so because matter is described by quantum mechanics. What controls matter, the wave function. Therefore the right interpretation would offer solution to how qualia is related to the wave function which describes matter. Get it? If you can see logical flaw in this argument, pls justify your counter arguments (including you Demystifer... if you can offer arguments that qualia is related to spacetime and not to matter, then pls. explain why you think it is so). If you or anyone can convince me qualia is not related to quantum mechanics. Then pls. do so and I'm outta here. I already spent 8 years trying to understand all this and frustrated the answers are so far away. But know that either by quantum or spacetime or by hooks and by crooks, we will arrive at the real physics of qualia.

 

[ZapperZ]

Where is the original research article, rather than just internet sites jaw-boning about it third hand--like this one?

https://www.physicsforums.com/showpost.php?p=3336459&postcount=136

Zz.

 

[Demystifier]

Varon, there is serious logical flaw in your argument, but it would be too much off topic to discuss it here. You may open a new thread on it. If the authorities move it to the Philosophy forum, inform me by PM about your thread and I will respond there.

 

[ZapperZ]

Varon, there is serious logical flaw in your argument, but it would be too much off topic to discuss it here. You may open a new thread on it. If the authorities move it to the Philosophy forum, inform me by PM about your thread and I will respond there.

This thread cannot be moved to the Philosophy forum because most of it are on a physics discussion of the experiment. Those who wish to continue that this new line of discussion should open a new thread there, with the caveat that it MUST follow the Guidelines set by the Philosophy forum.

Zz.

 

[Varon]

Ok Zapper. Now on topic.

http://www.sciencemag.org/content/332/6034/1170.full

Has anyone tried purchasing the article? How much is it? Do you think it would end up in arxiv sometime soon? In the past there was this Asfar (what's the correct spelling?) paper about wave and particle being displayed at the same time.. but it's controversial. I wonder if this would end up like it. How many here believe Asfar indeed show particle and wave can appear at the same time versus it's just some kind of misconception?

 

[Demystifier]

Has anyone tried purchasing the article? How much is it?

I see the paper automatically, because my institution pays for it. I don't know how much.

 

[Varon]

Varon, there is serious logical flaw in your argument, but it would be too much off topic to discuss it here. You may open a new thread on it. If the authorities move it to the Philosophy forum, inform me by PM about your thread and I will respond there.

Done. https://www.physicsforums.com/showthread.php?t=505217

 

[Demystifier]

In the past there was this Asfar (what's the correct spelling?) paper about wave and particle being displayed at the same time.. but it's controversial. I wonder if this would end up like it. How many here believe Asfar indeed show particle and wave can appear at the same time versus it's just some kind of misconception?

I have no idea what Asfar experiment is, but I have no doubts that all future experiments will only reinforce the validity of the experiment we discuss here. That's because this experiment has a strong theoretical basis, as we discussed here:
https://www.physicsforums.com/showthread.php?t=252491

 

[SpectraCat]

Also note that the correct interpretation would produce an emergence that won't be found in the incorrect interpretations. It's like the correct understanding of atomic theory has led to superconductivity.

*sigh* wrong again ... superconductivity is an experimental phenomenon that pre-dates QM. Kamerlingh-Onnes discovered it in 1911.

 

[Varon]

I have no idea what Asfar experiment is, but I have no doubts that all future experiments will only reinforce the validity of the experiment we discuss here. That's because this experiment has a strong theoretical basis, as we discussed here:
https://www.physicsforums.com/showthread.php?t=252491

Oh. Spelling is Afshar. His experiment tried to prove that wave and particle can be made to manifest at the same time contrary to the principle of complementary just like the new experiment of this thread. Anyway. What do you think of Afshar? Won't this new experiment end up like it, full of controversy?

http://en.wikipedia.org/wiki/Afshar_experiment

"Afshar's conclusion is that the light exhibits wave-like behavior when going past the wires, since the light goes through the spaces between the wires, but avoids the wires themselves, when both slits were open, but also exhibits particle-like behavior after going through the lens, with photons going to a given photo-detector. Afshar argues that this behavior contradicts the principle of complementarity since it shows both complementary wave and particle characteristics in the same experiment for the same photons."

 

[Varon]

*sigh* wrong again ... superconductivity is an experimental phenomenon that pre-dates QM. Kamerlingh-Onnes discovered it in 1911.

But the BCS model was discovered after QM. Because without understanding wave function, the dance of the cooper pairs can never be understood.

 

[ZapperZ]

Oh. Spelling is Afshar. His experiment tried to prove that wave and particle can be made to manifest at the same time contrary to the principle of complementary just like the new experiment of this thread.

Er... where did this new experiment claimed such a thing? You DO know that the supposed "path" that is being measured was deduced from the AVERAGE momentum measured at that location, don't you?

Considering that, from your post, that you haven't read the actual paper, do you think it is wise for you to make claims about what it says?

Zz.

 

[Demystifier]

Oh. Spelling is Afshar. His experiment tried to prove that wave and particle can be made to manifest at the same time contrary to the principle of complementary just like the new experiment of this thread. Anyway. What do you think of Afshar? Won't this new experiment end up like it, full of controversy?

http://en.wikipedia.org/wiki/Afshar_experiment

The source of controversy is the Afshar's claim that his experiment contradicts the principle of complementarity. By contrast, the authors of the paper we discuss here are too clever to make a similar statement for their experiment. By avoiding such a statement, they avoid the controversy as well.

 

[Varon]

The source of controversy is the Afshar's claim that his experiment contradicts the principle of complementarity. By contrast, the authors of the paper we discuss here are too clever to make a similar statement for their experiment. By avoiding such a statement, they avoid the controversy as well.

Nearly 80 years ago Bohr concluded that in the absence of measurement to determine its position, a particle has no position. What can you say about the latest experiment with regards to Bohr statement? I wonder if it is possible a single particle has no position, but a barrage of them can manifest positions even when unmeasured. This is one way to make compatible Bohr interpretation with the latest experiment (if it holds). Let me know how else to think of it.

 

[SpectraCat]

But the BCS model was discovered after QM. Because without understanding wave function, the dance of the cooper pairs can never be understood.

Cooper pairs only have to do with the understanding of superconductivity, not the phenomenon itself. You said:

It's like the correct understanding of atomic theory has led to superconductivity.

and

Superconductivity is an emergence.

That certainly implies that you think that the phenomenon of superconductivity is somehow "an emergence" (whatever that means). That is what I was responding to, and it is clearly wrong, since superconductivity was discovered long before BCS theory was developed. Are you claiming that a theory to explain a known experimental phenomenon is somehow "emergence"? That which certainly seems contradictory to the other definitions of emergence that you have given elsewhere, as well as the normal usage of emergence in the philosophical sense. How is the theoretical explanation of the known experimental phenomenon superconductivity, any different than the theoretical explanation of any other known physical phenomenon?

 

[f95toli]

Nearly 80 years ago Bohr concluded that in the absence of measurement to determine its position, a particle has no position. What can you say about the latest experiment with regards to Bohr statement? I wonder if it is possible a single particle has no position, but a barrage of them can manifest positions even when unmeasured. This is one way to make compatible Bohr interpretation with the latest experiment (if it holds). Let me know how else to think of it.

But again, you seem to think that this experiment tells us something profound about QM, that we did not already now. The experiment does not tell you anything about "which path" for a single particle,
Weak measurements are nothing new, and there are plenty of related experiments that have tested things like the relation between T2 and information loss etc.
So again, this is a nice experiment but it agrees with standard QM and is independent of interpretation.

 

[Fyzix]

Varon, PLEASE just stop!
We understand you are curious, but if you continue to spew contradicting ******** in every other post, someone will have to ban you.

One day you buy 10 books about MWI, talk about sniping Obama in another universe and wanting to merge with this image completely.

The next day your in a post talking about "there is no particle, no wave, just a probability cloud"

Then it's this god damn Neumaier interpretation.
If his interpretation is so good, why the hell isn't ANYONE talking about it?
You realize that people come up with pet theories 24/7 that never amount to anything right?
Just because he has managed to convince you, doesn't mean it's right, because let's be honest here, you pretty much believe ANYTHING.

Also please, stop reading a wikipedia article half way through, then come here and critize people for not knowing what you think you just understood from reading 3minutes about something...

Being curios and asking question is good, it's what science is about, but you are frankly just ignorant and annoying at this point.
If you want to understand QM and the measurement problem, read about each interpretation and it's problems, then conclude for your self.

 

[Demystifier]

Nearly 80 years ago Bohr concluded that in the absence of measurement to determine its position, a particle has no position. What can you say about the latest experiment with regards to Bohr statement? I wonder if it is possible a single particle has no position, but a barrage of them can manifest positions even when unmeasured. This is one way to make compatible Bohr interpretation with the latest experiment (if it holds). Let me know how else to think of it.

Yes, the experiment is compatible with the Bohr interpretation, and this is roughly how it can be thought of.

 

[Varon]

Varon, PLEASE just stop!
We understand you are curious, but if you continue to spew contradicting ******** in every other post, someone will have to ban you.

One day you buy 10 books about MWI, talk about sniping Obama in another universe and wanting to merge with this image completely.

The next day your in a post talking about "there is no particle, no wave, just a probability cloud"

Then it's this god damn Neumaier interpretation.
If his interpretation is so good, why the hell isn't ANYONE talking about it?
You realize that people come up with pet theories 24/7 that never amount to anything right?
Just because he has managed to convince you, doesn't mean it's right, because let's be honest here, you pretty much believe ANYTHING.

Also please, stop reading a wikipedia article half way through, then come here and critize people for not knowing what you think you just understood from reading 3minutes about something...

Being curios and asking question is good, it's what science is about, but you are frankly just ignorant and annoying at this point.
If you want to understand QM and the measurement problem, read about each interpretation and it's problems, then conclude for your self.

I already mentioned that on a monday I'm a Many Worlder, on a tuesday, I'm a follower of Neumaier, on a wednesday, I'm a Bohmian, on a thursday, A Copenhagenist, on a friday, A follower of Objective Collapse, on a saturday, other interpretations, on a sunday, pure QM dumb down shut up and calculate Statistical Interpretation. This it one way to get unbiased. Yes. I'm quite ignorant. Anyway. I'll sleep now. It's nightime in my place. Tomorrow. I'll hold no interpretation to give you spaces. Anyway. Continue your discussions. I'm just attracted to this thread "What are the implications of this experiment?" because I thought it is some kind of breakthrough (akin to discovery of the Higgs) and pretty excited.

 

[Demystifier]

I already mentioned that on a monday I'm a Many Worlder, on a tuesday, I'm a follower of Neumaier, on a wednesday, I'm a Bohmian, on a thursday, A Copenhagenist, on a friday, A follower of Objective Collapse, on a saturday, other interpretations, on a sunday, pure QM dumb down shut up and calculate Statistical Interpretation. This it one way to get unbiased.

I love it.

 

[yoda jedi]

from the creator of weak measurements (Yakir Aharonov):

http://www.tau.ac.il/~yakir/yahp/yh30

..."A description of quantum systems at the time interval between two successive measurements is presented. Two wave functions, the first preselected by the initial measurement and the second post-selected by the final measurement describe quantum systems at a single time"...http://www.aps.org/units/gqi/newsletters/upload/fall09.PDF

..."The "keynote" speaker -- and certainly the most renowned – was Yakir Aharanov [ChapmanUniversity]. Armed with only a pen, he gave a very nice derivation of his two-state formalism for postselected systems, and then discussed the intriguing aspects of "weak measurements" that can be performed on ensembles of such systems at intermediate times between the (strong) pre- and post- selections. If the "strength" of the weak measurement is weighted by some parameter a << 1, then the information one gains from the weak measurement scales as "a", but the net effect from the weak measurement on the intermediate quantum state scales like "a2". Aharanov concluded that for sufficiently weak measurements one could experimentally determine what was actually happening in a quantum system without disturbing it (given a large enough ensemble). From this perspective the "ontic" state would be best described by two wavefunctions; a "history vector" determined by the initial pre-selection as well as a "destiny vector" determined by the final post-selection. Ken Wharton's talk extended such a two-state formalism into the
relativistic domain, outlining a candidate psi-epistemic model in which a two-component classical field was constrained by two-time boundary conditions (corresponding to a preparation and a measurement).

Perhaps the first step in good science is to dispel mysticism. deBB theory dispels the mysticism of the observer's special position in the Copenhagen interpretation. The Copernican Principle holds. Ding dong, the witch is dead.

As usual, the above is my own humble opinion. Feel free to correct me if I have made a mistake.

well said.

.

 

[SpectraCat]

Aharanov concluded that for sufficiently weak measurements one could experimentally determine what was actually happening in a quantum system without disturbing it (given a large enough ensemble).

So what has changed? The weaker a measurement is, the less specific the information obtained can be about a given particle, so you need lots of statistics to build up the answer. Didn't we already know that? Surely the weakest measurement possible is no measurement at all ... in such a case you need to do an ensemble average to learn about the full probability distribution. I have never understood the emphasis on weak measurements as somehow refuting the CI ... as far as I can tell they are completely consistent with it.

 

[yoda jedi]

So what has changed? The weaker a measurement is, the less specific the information obtained can be about a given particle, so you need lots of statistics to build up the answer. Didn't we already know that? Surely the weakest measurement possible is no measurement at all ... in such a case you need to do an ensemble average to learn about the full probability distribution. I have never understood the emphasis on weak measurements as somehow refuting the CI ... as far as I can tell they are completely consistent with it.

are you furious ?

i don't like red letters...

...lol...

 

[SpectraCat]

are you furious ?

i don't like red letters...

...lol...

Sorry about the red letters ... but to me, that was the most important part of that comment, and you left it out of your original bold statement, so I wanted to give it extra emphasis in my post .

No, I am not furious ... just emphatic.

 

[yoda jedi]

Sorry about the red letters ... but to me, that was the most important part of that comment, and you left it out of your original bold statement, so I wanted to give it extra emphasis in my post .

No, I am not furious ... just emphatic.

nitpicking cos i posted it complete, re-read again...

if you like, all bolded...

.."The "keynote" speaker -- and certainly the most renowned – was Yakir Aharanov [ChapmanUniversity]. Armed with only a pen, he gave a very nice derivation of his two-state formalism for postselected systems, and then discussed the intriguing aspects of "weak measurements" that can be performed on ensembles of such systems at intermediate times between the (strong) pre- and post- selections. If the "strength" of the weak measurement is weighted by some parameter a << 1, then the information one gains from the weak measurement scales as "a", but the net effect from the weak measurement on the intermediate quantum state scales like "a2". Aharanov concluded that for sufficiently weak measurements one could experimentally determine what was actually happening in a quantum system without disturbing it (given a large enough ensemble). From this perspective the "ontic" state would be best described by two wavefunctions; a "history vector" determined by the initial pre-selection as well as a "destiny vector" determined by the final post-selection. Ken Wharton's talk extended such a two-state formalism into the relativistic domain, outlining a candidate psi-epistemic model in which a two-component classical field was constrained by two-time boundary conditions (corresponding to a preparation and a measurement)"......lol...
.