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RECENT POSTS IN THIS TOPIC

Jennifer Nielsen: on 5/30/18 at 19:59pm UTC, wrote I'd argue it is much more natural to present that quantum coherence is...

Lawrence Carson II: on 4/28/16 at 18:34pm UTC, wrote Please excuse my sophomoric question but I am very, very curious and...

Eckard Blumschein: on 8/14/15 at 5:45am UTC, wrote Dear Rob, I beg your pardon. In a hurry I wrote Bob instead of Rob, and I...

Eckard Blumschein: on 8/12/15 at 7:16am UTC, wrote Yes Bob, I see the physiologically plausible processing of ITD and ILD...

Robert McEachern: on 8/10/15 at 18:13pm UTC, wrote Eckard, "Well, phase differences e.g. between left and right ear can be...

Eckard Blumschein: on 8/10/15 at 6:25am UTC, wrote John C, Didn't we deviate a lot from topic? I have to apologize for my...

Eckard Blumschein: on 8/10/15 at 4:50am UTC, wrote Rob, I referred to your admission of Aug. 5: "a real-valued description is...

Robert McEachern: on 8/9/15 at 16:50pm UTC, wrote Eckard, "Rob and many others are just focusing on the astonishing...



FQXi FORUM
September 26, 2021

CATEGORY: Ultimate Reality [back]
TOPIC: Quantum Coherence = Entanglement [refresh]
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FQXi Administrator Zeeya Merali wrote on Jul. 23, 2015 @ 16:43 GMT
I'm opening this thread shamefully late, based on recent FQXi funded research by Gerardo Adesso and colleagues, whose work was covered in Phys.Org -- as spotted at the time, by John Merryman.

We will, of course, be covering Adesso's work in more detail on the site as we profile his grant, in depth. But in the meantime, here's a space to discuss the team's exciting paper in Physical Review Letters.

From Lisa Zyga's article on Phys.Org:

"Quantum coherence and quantum entanglement are two landmark features of quantum physics, and now physicists have demonstrated that the two phenomena are "operationally equivalent"—that is, equivalent for all practical purposes, though still conceptually distinct."

"The physicists arrived at this result by showing that, in general, any nonzero amount of coherence in a system can be converted into an equal amount of entanglement between that system and another initially incoherent one. This discovery of the conversion between coherence and entanglement has several important implications. For one, it means that quantum coherence can be measured through entanglement. Consequently, all of the comprehensive knowledge that researchers have obtained about entanglement can now be directly applied to coherence, which in general is not nearly as well-researched (outside of the area of quantum optics)."

Read more here.

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Thomas Howard Ray wrote on Jul. 24, 2015 @ 21:30 GMT
It seems to me that things which are " ... equivalent for all practical purposes, though still conceptually distinct" is a restatement of the measurement problem.

Here, a miracle occurs.

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Robert H McEachern replied on Jul. 25, 2015 @ 14:39 GMT
Tom,

As I have pointed-out before ab+ac = a(b+c) are "equivalent for all practical purposes, though still conceptually distinct." Unfortunately, conjuring-up "interpretations" of the mathematical equations of quantum theory, are not "practical purposes", and remain "conceptually distinct" from the measurement problem. One cannot measure or observe any differences, between the results produced by mathematical identities, even when the physical entities modeled by those identities, are indeed "conceptually distinct".

Rob McEachern

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Thomas Howard Ray replied on Jul. 25, 2015 @ 17:28 GMT
Rob,

Can you show me that the case of mathematical identities differs from the measurement problem? It is otherwise superfluous to say that two things are "conceptually distinct" while being operationally equivalent.

If indeed mathematical identities are all that is required, then the model is complete -- things that are not differentiable are identical. But since the measurement problem remains, the model is incomplete. This looks like a kludge.

I guess I agree with you. Except to say I do not see that the measurement problem is "conceptually distinct" from attempts to show that quantum coherence depends on entanglement. Entanglement is not an observable.

Choose coherence or choose entanglement. Miracles are superfluous, like phlogiston.

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Robert H McEachern replied on Jul. 25, 2015 @ 19:58 GMT
Tom,

"Entanglement is not an observable." Causes are generally not observable. Only their effects are observable.

Suppose one measured some data, produced by a black box, and found that it "obeyed" the equations 2sin(a)cos(b)=sin(a+b)+sin(a-b).

Which is the correct, physical cause for this effect?

1) inside the black box is a circuit that sums two sinusoids, to produce a superposition.

2) inside the black box is a circuit that modulates one sinusoid with another.

The measurement can decide which mathematical identities completely describe the observable data. But those mathematical identifies cannot uniquely determine which type of device/circuit created the data.

These two things AWAYS produce measurably equivalent results, but they are not "conceptually equal".

"things that are not differentiable are identical." The two things above are highly differentiable. If one opens the black box, the circuits will be observed to be obviously different. They just cannot be differentiated by observing only the outputs they produce.

Why do such thing matter? The Fourier Transform describing a Histogrammer, is mathematically identical to the Fourier Transform, used to describe superpositions in QM. The former provides a "conceptually distinct" explanation, for why QM measurements correspond to probabilities. The latter does not, even though the two are mathematical identities.

Rob McEachern

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Robert H McEachern wrote on Jul. 26, 2015 @ 14:51 GMT
There are no certain answers to metaphysical questions. Nor can causes be certainly identified for physical effects. All that can be done, with certainty, is to show that a theory either agrees or disagrees with the observations. Even when it does agree, it may not agree for the reasons one supposes that it does. That is the problem with metaphysical questions.

"If one assumes a probabilistic outcome." One does not need to assume anything. One merely has to take note of the perfect correlation between some computed results, and some observed behaviors. All the various assumptions come into play, only when one attempts to "interpret" the cause of such observed effects.

The QM probability models make predictions that can be compared to observations.

"One can as easily devise a deterministic model." Perhaps. But, what verified predictions have they made, that differ from those made by the probabilistic models?

Rob McEachern

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Thomas Howard Ray replied on Jul. 26, 2015 @ 16:56 GMT
"'One can as easily devise a deterministic model.' Perhaps. But, what verified predictions have they made, that differ from those made by the probabilistic models?"

What verified predictions have been made by probabilistic models?

The prediction comes post observation.

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Robert H McEachern replied on Jul. 26, 2015 @ 20:26 GMT
One of the more famous QM predictions was Dirac's prediction of the existence of the positron, before it was observed.

"The prediction comes post observation." All theories are preceded by at least some observations - those that inspired the theory. But subsequent use of the theory, has enabled many predictions of future observations. Virtually all sophisticated, communications systems use probability models to predict error (both random and non-random) performance; including predictions of what types of techniques will enable the detection and mitigation of those errors.

Statistical Mechanics has also developed many "laws", that resulted in theoretical descriptions of yet to be observed phenomenon.

Rob McEachern

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Thomas Howard Ray replied on Jul. 27, 2015 @ 12:38 GMT
Dirac's prediction is from special relativity. It is already implied in E^2 = m^2c^4 + (pc)^2. It's just that he took seriously the case of a particle with zero momentum and nonzero energy that relativists had dismissed as nonphysical. Symmetry demands it, however.

Not all theories are based on prior observations. Newton's dictum, hypotheses non fingo, favors correspondence of mathematical theory to physical result, and drove the whole of rational science for 300 years until scientists got into the bad habit of imposing metaphysical ideas on events they can't explain rationally.

Predicting error is useful for control systems, with arbitrary boundaries. For nature at its foundation, unboundedness is a primary property.

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Lawrence J. Carson II wrote on Apr. 28, 2016 @ 18:34 GMT
Please excuse my sophomoric question but I am very, very curious and passionate about the subject of .

The Framework

For a moment, let us assume that the framework of context always controls output content, i.e. function precedes form. Let us assume that it is the “Contextual Dimension of Singularity” … that sets and controls the unfolding Precursor Principles of Superposition … within Duality … that in turn . . . “Manifest the Time-Space-Energy Content” of quantum wave coherence and particle quantum entanglements .

The Question

With this simplistic Meta cause-effect assumption, what might researchers discover if they were to assume that the Meta Contextual Framework of Singularity is the core essence of Consciousness … that gives birth to the Duality of time-space-conscious-energy states of inter and intra-relationships that in turn gives rise to the Superposition Principles of both quantum wave coherence and particle quantum entanglements.

If all energy is in fact conscious - which would be mirrored by the fact that all states of consciousness are energetic- then perhaps we should now be attempting to uncover the metrics of … the very “Synergistic Attributes” of consciousness.

I Need Help

Will someone please contact me as I am now looking for a research institution to empirically test my hypothesis “On Understanding the Ontology of the Conscious Operating System of the Universe?

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Jennifer L Nielsen wrote on May. 30, 2018 @ 19:59 GMT
I'd argue it is much more natural to present that quantum coherence is equivalent to superposition and that entanglement is equivalent to superposition over a couple (or multitude) of diverse "sets" rather than a single "set"

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