Entanglement (split from Multiversal brain electron quantum entanglement)

[Kartazion 3]

2 hours ago, Markus Hanke said:

No. Quantum entanglement does not allow for the instantaneous transmission of information. 

In the principle of nonlocality or not:

Either the information is given at the start of the entanglement, then the information is given thereafter until it is read;
Or the information is given later when we discover the state of one of the two praticles which acts on the other not instantly at c speed?

Edited October 10, 2020 by Kartazion

[Bufofrog 158]

7 minutes ago, Kartazion said:

In the principle of nonlocality or not:

Either the information is given at the start of the entanglement, then the information is given thereafter until it is read;
Or the information is given later when we discover the state of one of the two practitioners which acts on the other not instantly?

This quote below is from is from https://en.m.wikipedia.org/wiki/No-communication_theorem, it seems like a good article.

from quantum information theory which states that, during measurement of an entangled quantum state, it is not possible for one observer, by making a measurement of a subsystem of the total state, to communicate information to another observer. 

[Kartazion 3]

12 minutes ago, Bufofrog said:

from quantum information theory which states that, during measurement of an entangled quantum state, it is not possible for one observer, by making a measurement of a subsystem of the total state, to communicate information to another observer. 

But this rule is related to an observer, not an observable since the observable can be indicative for both observers. 
In other words if the spin is read from one side, then the spin of the other entangled particle can be read at an opposite value.

There you have the Action at distance https://en.wikipedia.org/wiki/Action_at_a_distance

That is, it is the non-local interaction of objects that are separated in space.

[Bufofrog 158]

4 hours ago, Kartazion said:

That is, it is the non-local interaction of objects that are separated in space.

And the interaction may well be instantaneous.  But there is no information that can be communicated this way.

[Kartazion 3]

3 minutes ago, Bufofrog said:

And the interaction may well be instantaneous.  But there is no information that can be communicated this way.

The sentence came from wikipedia, as well as the following:

In physics, action at a distance is the concept that an object can be moved, changed, or otherwise affected without being physically touched (as in mechanical contact) by another object. That is, it is the non-local interaction of objects that are separated in space.

5 hours ago, Bufofrog said:

from quantum information theory...

and from quantum information (not theory) https://en.wikipedia.org/wiki/Quantum_information

Any change in state of one entangled particle automatically affects the other. We must therefore be able to explain how "information" is transmitted from one entangled particle to another.
 

The "information" can be given just before entanglement by hidden variable and retained in memory during the entanglement, for after discovering its state(s).

Or the information is given later and is transmitted from one entangled particle to another when we want to read its states.

This is why we speak of nonlocality and action at a distance for this specific observed case. This is valid for the quantum teleportation.
 

@Markus Hanke ?
 

[Markus Hanke 467]

14 hours ago, Kartazion said:

The "information" can be given just before entanglement by hidden variable and retained in memory during the entanglement, for after discovering its state(s).

Or the information is given later and is transmitted from one entangled particle to another when we want to read its states.

This is why we speak of nonlocality and action at a distance for this specific observed case. This is valid for the quantum teleportation.
 

@Markus Hanke ?
 

Quantum entanglement is neither to do with non-locality, nor with action at a distance; it has to do with non-separability of states, and statistical correlation of measurement outcomes. This difference is crucially important. The outcome of each measurement is subject to the usual rules of quantum mechanics, so the entanglement is not apparent to either one of the observers until they compare measurement outcomes - which is of course only possible at or below the speed of light. So no exchange of information at superluminal speeds is possible; and of course it can’t be, since entanglement features in relativistic quantum mechanics.

[Kartazion 3]

41 minutes ago, Markus Hanke said:

Quantum entanglement is neither to do with non-locality, nor with action at a distance; 

Bravo!

+1

One day Einstein later famously derided quantum entanglement as "spukhafte Fernwirkung".

[joigus 346]

1 hour ago, Markus Hanke said:

Quantum entanglement is neither to do with non-locality, nor with action at a distance; it has to do with non-separability of states, and statistical correlation of measurement outcomes. This difference is crucially important. The outcome of each measurement is subject to the usual rules of quantum mechanics, so the entanglement is not apparent to either one of the observers until they compare measurement outcomes - which is of course only possible at or below the speed of light. So no exchange of information at superluminal speeds is possible; and of course it can’t be, since entanglement features in relativistic quantum mechanics.

Exactly my usual points about this question.

21 hours ago, Kartazion said:

Either the information is given at the start of the entanglement, then the information is given thereafter until it is read;

Correlations are there since the very start of the state preparation. So nothing non-local is implied.

This is the problem: Suppose elementary particles (say, electrons) are coloured balls. Balls can be found to be in any colour state as referred to a basis R, G, B, and you have devices to measure this "colour."

You set both balls to be in an overall state that is white (colourless). So there is perfect anticorrelation; when one of them is found to be at R (total redness) the other one is found to be at GB (total anti-redness). For this you need a specific "redness" detector. But you can not say the ball was red before you measured its level of redness. And the reason is that whenever you measure a different colour component (say, brownness) the particle appears to be either brown or anti-brown (whatever that decomposition is in the RGB basis.) You see our predicament: How did the particle "know" I was going to measure the level of "brownness"? If my particle produced "anti-brown," sure enough, the other one produces "brown."

The problem, thus, is not any communication bridge between the particles. The problem is your classical mind: Your classical mind demands the particles to possess an attribute (namely, definite colourness) that is not there. The property that is packaged in the quantum state is a predicate about both particles, which, when referred to your classical mind, can only be expressed as this predicate:

"Whatever the colourness of particle (1) is measured, particle (2) will produce the corresponding anti-colourness if the same colourness component is measured."

You can write down this property quite simply: J = C_i(1) + C_i(2) = 0 for any possible i-projection in the colour space. But you cannot attribute any particular C_i(1) or C_i(2) separately.

Edited October 11, 2020 by joigus

[Kartazion 3]

9 minutes ago, joigus said:

Exactly my usual points about this question. +1

Yes it's ambiguous for others who Demystifies Entanglement and Quantum Nonlocality or find A Closer Connection Between Entanglement and Nonlocality

But I understood that both have nothing to do.

20 minutes ago, joigus said:

Correlations are there since the very start of the state preparation. So nothing non-local is implied.

It is true that the correlation was subject to debate namely the transfer comes at the start or after.

For the rest it is a nice explanation. Thank you
 

[joigus 346]

35 minutes ago, Kartazion said:

Yes it's ambiguous for others who Demystifies Entanglement and Quantum Nonlocality or find A Closer Connection Between Entanglement and Nonlocality

Thank you for the references. Yes, this (mild) scepticism has been in the air for quite some time. Back in year 2000 you simply could not say you had problems with Copenhagen's interpretation without being classed as a heretic. It was dogma, no doubt due to its astonishing calculational power. Adding to it was Von Neumann's impressive authority on the matter, that went almost unchallenged for decades.

It is my posture that the standing uneasiness can be addressed through a concept sketched by John Bell's (one of the first Copenhagen's sceptics) notion of beables.

If you wholeheartedly accept the fundamental complex-number mapping of "reality" that QM persistently suggests, you can complex-parametrize these states (the way you usually do in QM) and further assume that part of these quantum-dynamical variables can never be measured --overall phase, gauge arbitrariness, spin projections that are not being measured... What you see in an experiment would just be certain real-number projections of these essentially complex states. IOW, any physical system would package a residual internal entropy that cannot be set to zero by experimental determinations. Again (mathematically) IOW: Quantum states can be set in eigenstates of complex operators that are not Hermitian (those would be the beables, what physical systems "are",) but measuring processes (and their outputs) must be represented by Hermitian operators and their eigenvalues (those would be the observables, what systems "look like" to other systems, which we can call observers.) That would be the reason why pure quantum states cannot be generally purely, unambiguously, "coloured" (in my analogy). They would be chameleonically coloured (in your 1st-reference's parlance.) They always look "coloured" whenever I look at them. But they are only "complex-coloured" internally. Still IOW: they have complex colours; I only see real colours.