Loophole-free demonstration of nonlocality?

[audioloop]

Can mechanics be improved?|Does
the previous conclusions mean that mechanics
is the ultimate theory and will not experience any further
improvement in the future? Not by any means. Quan-
tum physics has still to solve for instance the so called
\measurement problem"

I don't think the measurement problem (cat paradox) has been resolved at all.

i agree.
---------
and related/connected to:
(regardeless of loopholes)

Is anyone familiar with Suarez's papers in this area? I've posted his most recent and pertinent papers on the topic below and even though I read them all, I'm still having trouble understanding his arguments:

Decision at the beam-splitter, or decision at detection, that is the question
http://lanl.arxiv.org/pdf/1204.5848.pdf

that's why I say:

Holism is more than Non-Separability as Contextuality is more than Non-Locality
---
"a physical theory is holistic if and only if it is impossible in principle to infer the global properties,
as assigned in the theory, by local resources available to an agent, there is no way we can find out about it using only local means, i.e., by using only all possible non-holistic resources available to an agent. In this case, the parts would not allow for inferring the properties of the whole, not even via all possible subsystem property determinations that can be performed"

Seevinck. (Epistemological Holism, physical property holism).
(unlike of Ontological Holism, Nonseparability).


how, when and what it can posit the cause of explanation (determination) of values
or are values just "parts" of a single fact or process (as matter of fact, not so composed) ?Hierarchical Status

Holism -> Non separability -> Contextuality -> Nonlocality

Syntactical Reality
.

or/and maybe how to infer the properties (value of parts) from the whole.------

Is anyone familiar with Suarez's papers in this area? I've posted his most recent and pertinent papers on the topic below and even though I read them all, I'm still having trouble understanding his arguments"Empty waves", "many worlds", "parallel lives" and nonlocal decision at detection
http://lanl.arxiv.org/pdf/1204.1732.pdfDecision at the beam-splitter, or decision at detection, that is the question
http://lanl.arxiv.org/pdf/1204.5848.pdf

decision: before, beginning, interim, or detection.

"Empty waves", "many worlds", "parallel lives" and nonlocal decision at detection
http://lanl.arxiv.org/pdf/1204.1732.pdf

..."The experiment does not require Bell's inequalities and is loophole-free"...

cos bell`s is about before emision (pre-existing properties).but i don't follow that argument (stricto sensu) because in any case, if one argues that the non-locality is in the detection, it can be said that comes from the beginning and there is no way to establish or prove (or disprove) that assertion.

 

[San K]

My point is that the point of Schrodinger was not to illustrate (or better understand) entanglement, but to show that extrapolating quantum mechanical conclusions to the macro world leads to absurdity.

agreed martin. that's what I was saying. however I think many people wrongly believe that there is an unresolved/un-solved paradox.

for example the twin paradox, in relativity, is a resolved paradox, because we have an explanation for it. thus it is not really a paradox.

it's just a means to illustrate.

same with Schrodinger's cat

 

[audioloop]

From what they say themselves, it's clear that what they did (I did not check their claims though) is a from -free demonstration of violations of the Bell inequalities and, therefore, from ruling out all local realistic theories.

and re-stated

..."Simultaneously closing these three major loopholes in a single experiment excluding an important sub-class of local realistic theories is a major step forward, particularly with regard to future loophole-free experiments testing Bell inequalities, which would exclude all local realistic theories"...
Loophole-free Einstein-Podolsky-Rosen experiment via quantum steering
http://arxiv.org/ftp/arxiv/papers/1111/1111.0760.pdf
-----
other

Detection loophole in Bell experiments: How postselection modifies the requirements to observe nonlocality
http://pra.aps.org/abstract/PRA/v83/i3/e03212
http://arxiv.org/pdf/1010.1178.pdf

"A common problem in Bell-type experiments is the well-known detection loophole: if the detection efficiencies are not perfect and if one simply postselects the conclusive events, one might observe a violation of a Bell inequality, even though a local model could have explained the experimental results. In this paper, we analyze the set of all postselected correlations that can be explained by a local model, and show that it forms a polytope, larger than the Bell local polytope. We characterize the facets of this postselected local polytope in the Clauser-Horne-Shimony-Holt scenario, where two parties have binary inputs and outcomes. Our approach gives interesting insights on the detection loophole problem."

...One of these loopholes is known as the detection loophole [7]. Typically, in photonic experiments the detection
efficiencies are not perfect, and one usually post-selects the detected events to show a violation of a Bell inequality. However, there might exist a model that exploits the detector inefficiencies to reproduce the experimental data [7, 8], in perfect agreement with Bell’s assumption of local causality [1]. In order to circumvent this problem, one usually resorts to the fair sampling assumption, that the detected particles are representative of all those emitted from the source, but this additional assumption is certainly not satisfactory. Closing the detection loophole would require either improving the detection efficiencies of the detectors used in Bell experiments, or finding Bell inequalities that are more robust to detection inefficiencies, as reported in [9–14]. Although the known necessary detection efficiencies are still quite high, a photonic detection-loophole-freeBell experiment seems possible in the near future...

dont know if loopholes are the ultimate answer but as they say Brunner, Wiseman, Zeilinger and others
"is a major step forward"

Efficiently heralded sources for loophole-free tests of nonlocality and singlephoton vision research.
Paul G. Kwiat, Kevin T. McCusker, Rebecca M. Holmes and Bradley Christensen.

...While the timing loophole can easily be closed in such a system by moving the detectors sufficiently far apart, closing the detection loophole is more difficult...

 

[bohm2]

This is an interesting paper that came out today that sort of relates to this thread:

Due to experimental limitations, fair sampling has been assumed in nearly every Bell experiment performed to date; a few exceptions include (5-8). To date, it has never been possible to avoid this assumption with photons due to the absence of efficient sources and detectors. Here we report the first Bell experiment with photons that does not rely on any fair-sampling assumption...We note that with our experiment, photons are the first physical system for which each of these three assumptions has been successfully addressed, albeit in different experiments.

Bell violation with entangled photons, free of the fair-sampling assumption
http://lanl.arxiv.org/ftp/arxiv/papers/1212/1212.0533.pdf

 

[nanosiborg]

This is an interesting paper that came out today that sort of relates to this thread:

Bell violation with entangled photons, free of the fair-sampling assumption
http://lanl.arxiv.org/ftp/arxiv/papers/1212/1212.0533.pdf

The abstract is, I think, not properly phrased.

The violation of a Bell inequality is an experimental observation that forces one to
abandon a local realistic worldview, namely, one in which physical properties are
(probabilistically) defined prior to and independent of measurement and no physical influence
can propagate faster than the speed of light.

I think it would be better to say that the violation of a Bell inequality is an experimental observation that forces one to abandon a certain way of modelling quantum entanglement, and that this doesn't necessarily inform regarding a local realistic worldview in which physical properties exist prior to detection and physical influences don't propagate faster than the speed of light.

Just a semantic point, but that's often the case with interpretation, or misinterpretation, as the case may be.

 

[zonde]

This is an interesting paper that came out today that sort of relates to this thread:

Bell violation with entangled photons, free of the fair-sampling assumption
http://lanl.arxiv.org/ftp/arxiv/papers/1212/1212.0533.pdf

Interesting indeed.

From paper:
"Eberhard’s inequality, which was proposed almost two decades ago (14), is a CH-type
Bell-inequality (18) that explicitly includes also undetected (inconclusive) events."

Both papers are behind paywall .
But from the paper it seems like this Eberhard’s inequality is the same CH74 inequality. So does it add that stuff about QM predictions for non-maximally entangled state so that this η≈66.7% limit should be enough?

From paper:
"Quantum-mechanically, the maximal violation is given by J/N = (1–√2)/2≈–0.207 (22)"
So for η≈66.7% it should be J/N=0. And for ηA=73.77% and ηB=78.59% reported in the paper it should be somewhere in between. They report J/N=–0.00524 (but with very low deviation).

 

[DrChinese]

This is an interesting paper that came out today that sort of relates to this thread:

Bell violation with entangled photons, free of the fair-sampling assumption
http://lanl.arxiv.org/ftp/arxiv/papers/1212/1212.0533.pdf

I missed that you had posted this, and started a separate thread on the paper today.