Quantum 'spooky action at a distance' becoming practical

January 5, 2018, Griffith University
Scientists from Griffith University (Australia) have overcome a major challenge connected to Einstein's 'spooky action at a distance' effect. Credit: Griffith University

A team from Griffith's Centre for Quantum Dynamics in Australia have demonstrated how to rigorously test if pairs of photons - particles of light - display Einstein's "spooky action at a distance", even under adverse conditions that mimic those outside the lab.

They demonstrated that the effect, also known as , can still be verified even when many of the photons are lost by absorption or scattering as they travel from source to destination through an optical fiber channel. The experimental study and techniques are published in the journal Science Advances.

Quantum nonlocality is important in the development of new global information networks, which will have transmission security guaranteed by the laws of physics. These are the networks where powerful quantum computers can be linked.

Photons can be used to form a quantum link between two locations by making a pair of photons that are "entangled" - so that measuring one determines the properties of its twin - and then sending one along a communication channel.

Team leader Professor Geoff Pryde said a quantum link had to pass a demanding test that confirmed the presence of quantum nonlocality between particles at either end.

"Failing the test means an eavesdropper might be infiltrating the network," he said.

"As the length of quantum channel grows, less and less photons successfully pass through the link, because no material is perfectly transparent and absorption and scattering take their toll.

"This is a problem for existing quantum nonlocality verification techniques with photons. Every photon lost makes it easier for the eavesdropper to break the security by mimicking entanglement."

Developing a method to test entanglement in presence of loss has been an outstanding challenge for the scientific community for quite some time.

The team used a different approach - quantum teleportation - to overcome the problem of lost photons.

Dr Morgan Weston, first author of the study, said they selected the few photons that survived the high-loss channel and teleported those lucky photons into another clean and efficient, .

"There, the chosen verification test, called quantum steering, could be done without any problem," she said.

Professor Geoff Pryde and Dr Morgan Weston led a study of Einstein's 'spooky action at a distance' effect at Griffith University in Australia. Credit: Griffith University
"Our scheme records an additional signal that lets us know if the light particle has made it through the transmission . This means that the failed distribution events can be excluded up front, allowing the communication to be implemented securely even in the presence of very high loss."

This upgrade doesn't come easy - the teleportation step requires additional high-quality on its own. These extra photon pairs have to be generated and detected with extremely high efficiency, in order to compensate for the effect of the lossy transmission line.

This was possible to achieve thanks to state of art photon source and detection technology, jointly co-developed with the US National Institute of Standards and Technology in Boulder, Colorado.

Although the experiment was performed in the laboratory, it tested channels with absorption equivalent to about 80 km of telecommunications optical fiber.

The team aims to integrate their method into quantum networks that are being developed by the Australian Research Council Centre of Excellence for Quantum Computation and Communication Technology, and test it in real-life conditions.

Explore further: Secure information transmission over 500m fiber links based on quantum technologies

More information: "Heralded quantum steering over a high-loss channel" Science Advances (2018). http://advances.sciencemag.org/content/4/1/e1701230 , DOI: 10.1126/sciadv.1701230

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fthompson495
3 / 5 (6) Jan 05, 2018
It's not non-locality, it's non-realism.

https://en.wikipe...n_theory

In de Broglie's double solution theory the particles of an entangled pair each have their own physical wave in the "sub-quantum medium" which, due to conservation of momentum when the pair are created, propagate with opposite angular momentums. In de Broglie's double solution theory, the particles do not have well defined spins prior to detection.[39] During detection, the local collapse of the local wave gives the local particle its spin. Since the waves propagate with opposite angular momentums, detecting the particles along the same axis causes their associated waves to collapse as exact opposites which give their associated local particles opposite spins. Detecting one particle has no effect on the other. No faster than light information transfer required as realism doesn't apply to the pair as the particles do not have pre-existing values.
sirdumpalot
not rated yet Jan 06, 2018
It's not non-locality, it's non-realism.


With you there, but https://en.wikipe...echanics and https://plato.sta...ational/
KBK
1 / 5 (1) Jan 06, 2018
See the PEAR research on psychic sensitivity for what is now thousands of peer reviewed experiments in Quantum non locality.

When you read it and then look at the overall works (meta works, which is what pear is, in the end)...then you will understand the nature of 3d timespace.

The non local aspects of reality as you know it, vs the huge and unrealized effects of quantum non locality... will be come clearly framed in your mind.

Time will go non linear bidirectional as will energy exchange (atomic and subatomic) ....and what Elon musk talks about regarding the nature of reality..will begin to become clear. That the odds of this being an original base reality are billions to one.

The understanding that this 'place' is an externally coupled non reality simulacrum with rules that have great power of cause and effect..

The crystal clear understanding that 'Objectivity' is completely impossible -by any measure.

The above article states all of it, if you can make the leap.
holoman
not rated yet Jan 06, 2018
https://drive.goo...Ob3RqAfd

Holographic entangled data storage
Da Schneib
5 / 5 (2) Jan 07, 2018
Slow, but almost usable. They've got to get that signal-to-noise ratio problem worked out. Little baby steps one at a time.
Noumenon
2 / 5 (4) Jan 07, 2018
It's not non-locality, it's non-realism.

In de Broglie's double solution theory the particles of an entangled pair each have their own physical wave....


To my knowledge, de Broglie's scheme has never actually been completed into a finished and complete theory... not for multiple particles in any case. Bohm of course extended it into a working theory, but de Broglie, rationally, objected to a physical pilot wave in configuration space.

In any case, since deBroglie didn't regard the wavefunction in Schroedinger's equation as a physical wave, why not just stick to the standard formalism in which one can say the same thing,... avoid the non-locality issue and reject a component of realism? Actual question)
Noumenon
2.3 / 5 (3) Jan 07, 2018
since deBroglie didn't regard the wavefunction in Schroedinger's equation as a physical wave...

Initially, de Broglie proposed a double solution approach, in which the quantum object consists of a physical wave (u-wave)


Yes, but I was referring to the other component of the double solution (the W-wave), Schrodinger's wavefunction.

He later formulated it as a theory in which a particle is accompanied by a pilot wave.

I think that was Bohm.... deBroglie didn't agree with a physical pilot wave precisely because it evolves in a tensor product space, a configuration space, not a 3d space for multiple particle systems.

Noumenon
2.3 / 5 (3) Jan 07, 2018
[de Broglie] later formulated it as a theory in which a particle is accompanied by a pilot wave.


I think that was Bohm.... deBroglie didn't agree with a physical pilot wave precisely because it evolves in a tensor product space,...

Nope, it was deBroglie in 1927-9, Bohm plagiarized all his stuffs many years later


You are mistaken....

"My first reaction on reading Bohm's work was to reiterate, [publish], the objections, insurmountable in my opinion, that seemed to render impossible any attribution of physical reality to the [wave-function] wave, and consequently, to render impossible the adoption of the pilot-wave theory." - Louis de Broglie

You're talking now about Schrodinger wave function, not pilot wave


You're confusing de Broglie's double solution (of which I was responding of), and the Bohm-deBroglie pilot wave theory.
Noumenon
2.3 / 5 (3) Jan 07, 2018
... the de Broglie double solution having the two components, the u-wave and the w-wave, the latter associated with the Schroedinger wavefunction and not considered a physical wave.
Noumenon
2.3 / 5 (3) Jan 07, 2018
de Broglie opposed Bohm's love of pilot wave from perspective of Schrodinger wave and his double solution theory, not with respect to physical realism of pilot wave.


No, he specifically rejected Bohm's pilot wave on account of it's necessary evolution in configuration space.

At any case, once some construct (like the wave function or pilot wave) enables us to predict results of real tangible experiments, I don't see reason, why not also consider it real


It would require postulating a potentially infinitely dimensional space as "real",... or diverging into metaphysics further by accepting MWI as literal.
Noumenon
2.3 / 5 (3) Jan 07, 2018
All interpretations of quantum mechanics have some tangible physical representation behind them which becomes less or more relevant from particular observational perspective.


Which is why proposing as 'real' an additional entity over and above the standard formalism is more from metaphysical desire than predictive desire,.. if the given alternative merely reproduces the same predictions in any case.

If an alternative predicted new observations over and above the standard accepted formalism, then certainly this would be grounds for inferring an additional component of [phenomenal] reality.


Noumenon
2.3 / 5 (3) Jan 07, 2018
Your first link only references one photon in the experiment. The issue, as pointed out, is with a single wavefunction description of a multiple particle system, which then does not evolve in normal space, but rather mathematical configuration space.
Noumenon
2.6 / 5 (5) Jan 07, 2018
More to the point, the notion of a configuration space, and a phase space are used in classical / analytical mechanics, but yet no one supposes these are more than mathematical spaces.

If an alternative theory like pilot wave, only reproduces the same predictive results and no further, and merely substitutes one set of conceptual problems with a different set, then it doesn't extend understanding further, but only as an aid perhaps given certain problems.

It's odd that the pilot-wave can effect the supposedly real particle, but yet that particle can not reciprocally effect the pilot-wave in turn, as there is no such mechanism in the theory. What kind of physics is that?

Da Schneib
5 / 5 (1) Jan 07, 2018
People get this incorrect impression that a quantum wavefunction means something's actually waving in real physical space. It doesn't really work like that. @Noum's point that the wavefunction can affect the particle but the particle can't affect the wavefunction is well taken, since it dispels this misconception.
Da Schneib
5 / 5 (1) Jan 07, 2018
For lurkerz who haven't studied up on this stuff, the way physics works with data and measurements, particularly when there are a large number of items, each with a large amount of data of various different sorts, is by organizing the data for each item in the same way, then constructing what is called a "configuration space" based on these items and these data. Ways of comparing, contrasting, averaging, combining, and other obvious operations to analyze these data are constructed that require much less calculation than would be required to analyze each datum on its own, which correspond to mathematical geometrical operations within this configuration space. The scientists and mathematicians (often the same people) create and check these operations to make sure that the results are the same as if they had calculated for each item separately. The use of these types of techniques has been the most effective task of physics since the seventeenth century.
[contd]
Da Schneib
5 / 5 (1) Jan 07, 2018
[contd]
Since the nineteenth century most serious physics has been done this way. Instead of dealing with individual equations, physicists deal with systems of equations, and instead of dealing with systems of equations they deal with operations in various abstract configuration spaces using only those operations that have been verified to produce correct results. So when someone talks about a configuration space for quantum particles, this isn't just x,y,z,t of some event, but a collection of coordinates for multiple events, and it's not just four parameters for those events but potentially hundreds for each event.

Pretending that a wavelike function in some configuration space that may not even contain position data is some sort of physical wave is not merely ignorant, it's risible.
Da Schneib
5 / 5 (1) Jan 07, 2018
Oh, and in case it's not clear, the Schroedinger wavefunction is nothing more than one of these geometrical operations that can be performed in configuration space and has been confirmed both by mathematics and by experiment to give valid results. This function happens to have some of the mathematical characteristics of the same functions worked out centuries ago to describe waves when they were being studied back then, and this is why it is called a "wavefunction," but this doesn't mean there are actual physical waves involved.
Da Schneib
5 / 5 (1) Jan 07, 2018
Good examples of these sorts of geometrical operations in configuration space are cross products and dot products, which are used all over physics for things like defining the angle and magnitude of the action of an electrical current in a generator, calculating the linear effects of torques, defining curl in electromagnetic theory, and the definition of work in a 3D space in terms of force and displacement.
Noumenon
2.3 / 5 (3) Jan 08, 2018
particle can not reciprocally effect the pilot-wave in turn, as there is no such mechanism in the theory

Of course it can: the pilot wave follows the particle not vice-versa and its wavelength changes with speed of particle (relative velocity toward observer) and so on...


You're mistaken. The particle is guided by the wavefunction (hense "pilot wave"), or more properly, the quantum potential which is determined from the wavefunction. The particle does not in turn effect this potential. It's the form of the apparatus that does so.

When you link to references that show 'pictures of the wavefunction', you're referencing the quantum potential in 3D space, but it is calculated from the wavefunction which determines its form and evoles in a tensor product space.
Da Schneib
not rated yet Jan 08, 2018
To put it another way, it's like claiming that the math of the Moon's orbit determines the orbit, instead of that the orbit determines the math.
Da Schneib
not rated yet Jan 08, 2018
Nice try at covering up, @macurinetherapy. Only problem, you're talking about the Hamiltonian, which is one of those geometric operations I was talking about. Which means you're still claiming the equation tells the Moon what to do instead of the Moon telling the equation what to do.

Dumb da dumb dumb. Dumb da dumb dumb duuuuhhhhh.
Da Schneib
5 / 5 (1) Jan 08, 2018
See, here's the thing about interpretations: we know the math works, but we don't know *why*. Whatever the underlying things are that make the math work, we don't know about them. But all the interpretations have to give the same results, and they all have to give the results the math does; otherwise they're not valid.

But the only reason we know the math works for sure is a) because it's rigorous math and b) because it agrees with experiment. We have no idea what the actual mechanism that underlies this is; we just know it works. Interpretations are just speculation about what the mechanism might be, not statements of what it is.

This is not true of classical mechanics; there, we *do* know why. Your problem, @macurinetherapy, is that you think there has to be some sort of answer for quantum physics just like there is for classical physics. Get over it.
antialias_physorg
5 / 5 (3) Jan 08, 2018
We shouldn't even expect to understand why it works. A 'why' is dependent on mapping stuff to experience (explanation by analogy). All our experiences are of the macro-world. We have no direct experiences where quantumphysical effects matter.

QM is more basic than anything we know or have ever experienced. If anything we can explain our macrocosmic experiences in terms of analogy from QM. But doing it the other way around would be futile (and also quite circular)
milnik
not rated yet Jan 08, 2018
For science there is a problem that there is no clear image and the exact path and way of moving celestial bodies. In the case of any kind of matter, there are the same laws. It should be known that the sum of kinetic and potential energy, one body in relation to the second-constant. This constant remains the same, and its members, potential and kinetic energy are exchanged depending on the position of the body in relation to the center of mass, or the energy center. There is a kinetic energy of radial velocity, which is transformed into a coupling of two spins of the same size and opposite directions. One spin is its own, and the other is a rotation around the center of mass on a sinusoidal radius.
milnik
not rated yet Jan 08, 2018
This is how the planet moves, and the wavy motion of particles, including the photons themselves, is formed in a similar way. But there must be a "backbone" that governs these movements. For everything made up of matter, it is substance Aether, which was rejected by science, and therefore there are no solutions for many phenomena. Without the existence of Aether, nothing in the universe would exist. From matter, matter and matter form everything that exists in the observer of the universe. All these formulas, measurements, and theories will be corrected when the existence of Aether is accepted. So I corrected Kepler's laws so that's how I write.
luke_w_bradley
5 / 5 (1) Jan 08, 2018
Da Schneib, thanks for notes to lurkerz. Educational!
Da Schneib
3 / 5 (2) Jan 08, 2018
We shouldn't even expect to understand why it works. A 'why' is dependent on mapping stuff to experience (explanation by analogy). All our experiences are of the macro-world. We have no direct experiences where quantumphysical effects matter.
We shouldn't expect, in fact, to ever understand why it works. The very foundations of logic and math are in the behavior of classical objects, and we already know that some of those foundations don't work with quantum mechanics. Things as basic as where an object is can't be reliably determined for every quantum particle, and that's merely the beginning.

That's not to say that there aren't some parameters of a quanta that are certain; for example, electric and other charges are not uncertain. But there are significant things we can't ever know about quanta for sure to ultimate accuracy. In fact, we can't even know them about classical objects to ultimate accuracy; but with quanta these inevitable inaccuracies are not swamped.
[contd]
Da Schneib
3 / 5 (2) Jan 08, 2018
[contd]
Now I will introduce a quibble: we have, with X-rays, been able to get short enough wavelengths to observe individual atoms' interactions in chemical reactions, something we didn't think we could do a few decades ago. But the scale of atoms is as far from the scale of quarks in a proton as the scale of atoms is from the classical realm, so I ain't exactly holdin' my breath. I will however point out that neutrino scans might eventually let us see things like the interactions of quarks in a proton.

QM is more basic than anything we know or have ever experienced. If anything we can explain our macrocosmic experiences in terms of analogy from QM. But doing it the other way around would be futile (and also quite circular)
Not sure I quite completely agree with this. I think the things we can know for certain about classical objects are different from those we can know about quanta.
[contd]
Da Schneib
3 / 5 (2) Jan 08, 2018
[contd]
I think one of the things that has been ignored is determining how logic would work if it were derived from quantum mechanics instead of classical mechanics. What would logic look like then, and what would the math derived from it look like?
KBK
not rated yet Jan 09, 2018
It would look kinda like the results of the PEAR research I mentioned earlier. That's how logic would work.

the record is already there... you just gotta put numbers on it. But, it is inherently slippery, that is part of it's nature. Good luck....

You'll make it to rules but not to specifics.

Kinda like, no, exactly like ---the quantum to newtonian issues we struggle with today.

Reality is what you make of it. Literally.

Objectivity is a non starter.

Sucks to be a book projecting scientific linear mind with a projected agenda into mathematical perfection. Not gonna happen. On average, yes, one will get a given consensus reality --- as stable.

In the specific.....?

No.
Da Schneib
1 / 5 (1) Jan 09, 2018
So, my question is, how do you make perpetual motion with urine therapy?
milnik
not rated yet Jan 10, 2018
In nature, in all celestial bodies, subatomic particles exist perpetuum mobile. That's how electrons, planets and so on behave.
The problem, in science, is that it ignored the existence of Aether, which is the basis for the formation of matter and for it to move without borders.
I have a simple proof that perpetuum mobile can be made in many ways.
sirdumpalot
not rated yet Jan 15, 2018
The very foundations of logic and math are in the behavior of classical objects, and we already know that some of those foundations don't work with quantum mechanics. Things as basic as where an object is can't be reliably determined for every quantum particle, and that's merely the beginning.


Take Rovelli's relational QM which has no absolute property or object - only a relational epistemology, and the Peano axioms, specifically the second one: "For every natural number x, x = x.".. this is a 0 information statement, meaning that numbers offer 0 information from their own frames of reference.

Both start from the same principle - the emptiness of inherent existence (that property and object are intrinsically dependent on observation/measurement - no Einstenian realism). The reason for the mathematical explicability of experience is that mathematics starts with this same 'empty of inherent existence' construct.. Physics needs to discover Nagarjuna.
AxnJxn
not rated yet Jan 23, 2018
Commenters, as I read through your discourse I am impressed with the passion that so many of you have through your insights and rebuttals. It also interests me that some of you comment in multiple postings, often times violently agreeing with each other without knowing it. If it pleases, might I offer just one subtle insight acquired along my journey, Physics is the study of our universe; what we know now we owe to those who came before us and what we learn we owe to each other. Classic physics taught us to observe our surroundings and apply disciplined practices to derive understanding. With this came a certain degree of predictability. Now, we are venturing into less clear regimes of knowledge that requires patience and curiosity, accompanied by friendly discourse. It is expected to have differing views, but let's debate and discover, together. I remain a student of life, eager to learn about it. Leave your wet umbrellas at the door and welcome each other and differing views.
milnik
1 / 5 (1) Jan 24, 2018
This astounding action at a distance, in photons and some waves of movement, can be real. But, if we want to find out and confirm this, we must take the substance of Aether as the basis of all creation and change. Aether is neither matter nor energy, nor some bubbles as the cats say, it is a substance that possesses electromagnetic properties. Science still does not know what photon is and how it originates and how it moves. It is a "condensate" of the gluon that "evaporated". This "pair" of gluon is the energy state of what remains as a pair of "emitted" particles of electron positron. This pair moves in the same way as the planet and its companion. One particle is guided by Aether, with its own spin, and the other around it rotates with a spin of the same size and opposite direction, following a sinusoidal radius.

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