Exploring Antoine Suarez's Work on Entanglement and Time

[nikman]

I should've said ORDERS OF magnitude in my first post.

 

[DrChinese]

I should've said ORDERS OF magnitude in my first post.

I messed up the same thing and edited my post. The article actually shows a graph of the various lower bounds, with 10,000c more or less being the absolute floor. It rises to about 100,000c at some angle settings. So I would conclude that it is as close to instantaneous as it gets.

As I re-read their conclusion:

"From these observations we conclude that the nonlocal correlations observed here and in previous experiments[1] are indeed truly nonlocal. Indeed, to maintain an explanation based on spooky action at a distance one would have to assume that the spooky action propagates at speeds even greater than the bounds obtained in our experiment."

...I guess they are distinguishing a) "nonlocal" (which is absolutely instantanteous, in keeping with Bohmian types); vs. b) "spooky action at a distance" which involves cause-effect, the transmission of quantum information from Alice to Bob (or vice versa).

In this case, I guess we are putting some constraints on the pilot wave mechanics. In the Bohmian program, there is an absolute time frame and so one of the measurements occurs first (which I will simply label as Alice). So we need to explain how a macroscopic polarizer setting at Alice influences a quantum outcome at Bob, but the setting at Bob does not influence the outcome at Alice (which would have already occurred). Or something, I guess I am still confused.

 

[nikman]

...I guess they are distinguishing a) "nonlocal" (which is absolutely instantanteous, in keeping with Bohmian types); vs. b) "spooky action at a distance" which involves cause-effect, the transmission of quantum information from Alice to Bob (or vice versa).

In this case, I guess we are putting some constraints on the pilot wave mechanics. In the Bohmian program, there is an absolute time frame and so one of the measurements occurs first (which I will simply label as Alice). So we need to explain how a macroscopic polarizer setting at Alice influences a quantum outcome at Bob, but the setting at Bob does not influence the outcome at Alice (which would have already occurred). Or something, I guess I am still confused.

I may be wrong, but if it helps any I think this experiment links all the way back to at least 2001, when Gisin conducted another experiment involving relativistic reference frames and a principle which in those days he called "multisimultaneity". It introduced the before-before configuration (since often referred to by Suarez):

http://arxiv.org/pdf/quant-ph/0110117v2

Here's a Suarez paper from Foundations of Physics last summer, discussing an approach which seems conceptually not dissimilar to the current one:

http://www.dancing-peasants.com/sciphil/Nonlocal_“Realistic”_Leggett_Models...pdf

Same material differently formatted:

http://www.quantumphil.org/SuarezFOOP201R2.pdf"5 Preferred Frame Models

"If one assumes that Bohm’s time-ordered nonlocality belongs to physical reality, one has to cast it into a description using real clocks and accepting the experimental result of the relativity of time. As said above, the essential ingredients of a realistic theory lead naturally to accept that the relevant clocks are those defined by the inertial frames of the beam splitters. In this sense, Bohm’s model [16] is the adequate time-ordered nonlocal description for entanglement experiments with beam splitters at rest. And its natural extension to experiments with beam splitters in motion is the model leading to the prediction that the nonlocal correlations should disappear in the before-before experiment [8, 9, 11, 12]. Therefore, this experiment proves nonlocal determinism in the testable relativistic extension of Bohm’s model [16] wrong."

For anyone who likes material in a colorful graphic format here's a link to a page of Suarez's website. "Is There Time in the Quantum World?" is obviously adapted from a PowerPoint presentation:

http://www.quantumphil.org/presentations.htm

 

[DrChinese]

"5 Preferred Frame Models

"If one assumes that Bohm’s time-ordered nonlocality belongs to physical reality, one has to cast it into a description using real clocks and accepting the experimental result of the relativity of time. As said above, the essential ingredients of a realistic theory lead naturally to accept that the relevant clocks are those defined by the inertial frames of the beam splitters. In this sense, Bohm’s model [16] is the adequate time-ordered nonlocal description for entanglement experiments with beam splitters at rest. And its natural extension to experiments with beam splitters in motion is the model leading to the prediction that the nonlocal correlations should disappear in the before-before experiment [8, 9, 11, 12]. Therefore, this experiment proves nonlocal determinism in the testable relativistic extension of Bohm’s model [16] wrong."

Thanks, this material is very helpful! Starting to fit together. So the pilot wave model imposes a requirement of "absolute time ordering", which the experiment effectively refutes (as much as it can be accepted - see below). This leaves the possiblity of a finite "spooky action at a distance" which exceeds 10,000c, which is the hard to swallow part you mention.

As to the experiment and the subsequent comments by Zeilinger et al, and the response to that: Zeilinger is saying that a more loophole-free version is needed. And Gisin et al say that the experiment was not attempting to close all loopholes, since the experiment was looking for evidence of a preferred frame and found none. They also say the "strict Einstein locality" condition has already been met (by Zeilinger's own work) and does not need to be tested in this format. I have a fundamental disagreement with the requirement of eliminating all loopholes simultaneously anyway. But I can see why Zeilinger would like this condition tested anyway - it quiets the critics. On the other hand, I doubt this experiment will satisfy Bohmians regardless (how could it?) and I am sure we will see more experimental tests of pilot wave theories.

 

[nikman]

Thanks, this material is very helpful! Starting to fit together. So the pilot wave model imposes a requirement of "absolute time ordering", which the experiment effectively refutes (as much as it can be accepted - see below). This leaves the possiblity of a finite "spooky action at a distance" which exceeds 10,000c, which is the hard to swallow part you mention.

As to the experiment and the subsequent comments by Zeilinger et al, and the response to that: Zeilinger is saying that a more loophole-free version is needed. And Gisin et al say that the experiment was not attempting to close all loopholes, since the experiment was looking for evidence of a preferred frame and found none. They also say the "strict Einstein locality" condition has already been met (by Zeilinger's own work) and does not need to be tested in this format. I have a fundamental disagreement with the requirement of eliminating all loopholes simultaneously anyway. But I can see why Zeilinger would like this condition tested anyway - it quiets the critics. On the other hand, I doubt this experiment will satisfy Bohmians regardless (how could it?) and I am sure we will see more experimental tests of pilot wave theories.

That analysis and summary definitely works for me. And it's useful. Thank you. Zeilinger has said he expects loophole-free Bell-type or Leggett-type tests to become available eventually that'll test both the reality and locality assumptions -- separately and simultaneously -- for models that allow for that, including I assume pilot-wave theories. It's clearly important to him. He wants to address the issue of what can be said about a world in which there's demonstrably no such thing as counterfactual definiteness.

He doesn't like many-worlds either, but the only m-w falsification test I know of (that doesn't involve committing suicide) is the one suggested by Rainer Plaga, which a lot of people think wouldn't fly anyway.

 

[Ilja]

I have a fundamental disagreement with the requirement of eliminating all loopholes simultaneously anyway. But I can see why Zeilinger would like this condition tested anyway - it quiets the critics. On the other hand, I doubt this experiment will satisfy Bohmians regardless (how could it?) and I am sure we will see more experimental tests of pilot wave theories.

Sorry, but there is an equivalence theorem: The predictions of pilot wave theories agree with the predictions of SQM.

Whatever is presented as "experimental tests of BM" is nonsense. (It remains to find out at which place the difference between dBB and the "dBB" which is "tested" is hidden. Some variant of search for hidden variables ;-))

And, of course, dBB in the relativistic case needs a preferred frame. Any "relativistic" variant which does not use a preferred frame is not dBB.

 

[Ilja]

Therefore, this experiment proves nonlocal determinism in the testable relativistic extension of Bohm’s model [16] wrong."

[16] refers to:

16. Bohm, D.: A suggested interpretation of the quantum theory in terms of “hidden” variables. I and II. Phys. Rev. 85, 166–193 (1952)

Thus, the author of this paper invents some personal "testable relativistic extension of Bohm’s model", which seems unpublished (once he refers to Bohms original paper and not the extension), and falsifies it. Big deal, and irrelevant.

Pilot wave theories, of course, use a preferred frame in the relativistic domain.

Experimental refutations of pilot wave theories are, at the same time, experimental refutations of SQM. Whatever is presented as "experimental refutation of BM against SQM" is nonsense.

 

[Ilja]

A recent experiment by Nicolas Gisin's group (with which Suarez is informally affiliated) claims that for the Bohmian model to work there'd need to be a superluminal influence operating at a magnitude four times greater than lightspeed.

http://arxiv.org/pdf/0808.3316

For the Bohmian model to work we need (as in classical Newtonian theory) infinite speed of information transfer. Any upper bound for violations of Bell's inequality would falsify pilot wave theories together with SQM.

That would be really interesting. But this result of the Gisin group is simply what is predicted by pilot wave interpretations.

 

[Alfi]

sorry to interrupt everybody throwing papers at each other.

but I'm slow in following, I try , and way back there was this statement that said;

"An elementary quantum system contains one bit of information."

?my question.

If you 'know' it's a 'one'
don't you also 'know' that it is not a 'not-one'?

In binary a 1 also tells me that it is not a 0. Instantly I have two pieces of information about a single bit.

again, sorry to interrupt but the question caught me.

can that not be considered as 'knowing' two somethings of information from a single 'bit'?

 

[nikman]

sorry to interrupt everybody throwing papers at each other.

but I'm slow in following, I try , and way back there was this statement that said;

"An elementary quantum system contains one bit of information."

?my question.

If you 'know' it's a 'one'
don't you also 'know' that it is not a 'not-one'?

In binary a 1 also tells me that it is not a 0. Instantly I have two pieces of information about a single bit.

again, sorry to interrupt but the question caught me.

can that not be considered as 'knowing' two somethings of information from a single 'bit'?

"1" and "Not-0" are synonyms if you only have two binary alternatives, "0" and "1". They're merely different ways of saying exactly the same thing. So it's still just one piece or bit of information.

However ... there's such a thing as a "trit" of information, which is base-3 instead of base-2. That'd be like sunny, rainy or who knows what the weather's like. And now I'm confused.