crowded quantum information

[joigus]

15 minutes ago, bangstrom said:

It isn't EM or limited to c and it is prior to an EM exchange of energy. John Cramer calls it a transaction between advance and retarded waves between a signal and receiver or quantum 'handshake'. Wheeler and Feynman had the same idea with similar names as have other theories but they all agree that it is a direct interaction between a signal and receiver.

This is based on TIQM, which you have declared yourself not to believe in before. Solutions to any wave theory based on advanced waves establish boundary conditions that guarantee that no signal can be "advanced" when everything is said and done. WF theory: absorber at infinity; QFT: Feynman-Stueckelberg propagator that guarantees fields commute or anti-commute at space-like intervals. I don't know TIQM in detail, but I'm sure it imposes boundary conditions to guarantee relativistic causality. Otherwise it would go directly into the trash can.

You're clutching at straws just in order not to answer to an embarrasing question.

At what point will you be done with the stubborn denial of an experimental fact?

Edited October 11, 2022 by joigus
minor correction

[bangstrom]

4 hours ago, joigus said:

This is based on TIQM, which you have declared yourself not to believe in before. Solutions to any wave theory based on advanced waves establish boundary conditions that guarantee that no signal can be "advanced" when everything is said and done. WF theory: absorber at infinity; QFT: Feynman-Stueckelberg propagator that guarantees fields commute or anti-commute at space-like intervals. I don't know TIQM in detail, but I'm sure it imposes boundary conditions to guarantee relativistic causality. Otherwise it would go directly into the trash can.

You're clutching at straws just in order not to answer to an embarrasing question.

At what point will you be done with the stubborn denial of an experimental fact?

I am in favor of TIQM but is not my favorite because I think other lesser known theories of light do a better job of of explaining the same things.

The question I won't answer is what?

That must be some ancient ‘fact’ you favor because you don’t appear to be aware of anything recent.

 

[Eise]

7 hours ago, bangstrom said:

Bell, Aspect and Clauser won the Nobel prize for demonstrating that the first signal was both not fixed from the start and also that it was superluminal.

Bell is, pity enough, dead, so he did not get a Nobel prize. You mean Clauser, Aspect, and Zeilinger.

And Zeilinger himself says in the book you introduced here in the discussion, that he thinks that of our presuppositions, we have to give up on reality, not on locality. Others, see my list of authors, take an even stronger position. QM is local.

And do you realise you really did not answer Swansont's question? 

11 hours ago, swansont said:

How can Bob read a signal before it gets to him?

You are talking around it, without answering the question.

2 hours ago, bangstrom said:

That must be some ancient ‘fact’ you favor because you don’t appear to be aware of anything recent.

Bullshit. Don't ever say this again. Or better show us where Joigus and Swansont are not uptodate, and you are.

Addition:

For what it is worth, the publication years of the sources of my 'authority list':

• Coleman:1994
• Kracklauer: 2002
• Zeilinger: 2010
• Susskind: 2015
• Gell-Man: 2016
• Hossenfelder: 2020

 

[joigus]

4 hours ago, bangstrom said:

I am in favor of TIQM but is not my favorite because I think other lesser known theories of light do a better job of of explaining the same things.

TIQM is not a theory of light. WF theory is. QFT is not.

4 hours ago, bangstrom said:

The question I won't answer is what?

This one (again):

8 hours ago, swansont said:

What interaction is used to send this qubit? Electromagnetic and gravitational are limited to c.

Will you ever answer this question?

You said,

8 hours ago, bangstrom said:

It isn't EM or limited to c and it is prior to an EM exchange of energy. John Cramer calls it a transaction between advance and retarded waves between a signal and receiver or quantum 'handshake'. Wheeler and Feynman had the same idea with similar names as have other theories but they all agree that it is a direct interaction between a signal and receiver.

It isn't EM, and Cramer calls it a transaction. Oh.

What the hell is it?

Will you finally stop talking about what it is not or how some people call it, come clean, and tell us what it is?

 

[bangstrom]

10 hours ago, joigus said:

TIQM is not a theory of light. WF theory is. QFT is not.

This one (again):

You said,

It isn't EM, and Cramer calls it a transaction. Oh.

What the hell is it?

Will you finally stop talking about what it is not or how some people call it, come clean, and tell us what it is?

 

TIQM is a theory of light. It is essentially the old Wheeler-Feynman absorber theory without the innumerable photons that all-but-one get absorbed.

I wasn’t trying to be evasive but I forgot that when explaining advances in QM from the past quarter century to novices it is necessary to explain the basics that are otherwise commonly understood.

The question is, What 'sends' a bit of information? The answer is nothing at all, überhaupt nichts, nada, nada, pues nada.

A quantum bit of information simply appears at both ends of an entanglement when entanglement is lost. With quantum teleportation, a qubit of information can be sent from one point to another but entangled particles act as if they are two particles at the same location so there is no ‘other’ location to ‘send’ a qubit of information to.

This defines what a qubit of information is. Form wikipedia;

“In quantum computing, a qubit (/ˈkjuːbɪt/) or quantum bit is a basic unit of quantum information—the quantum version of the classic binary bit physically realized with a two-state device. A qubit is a two-state (or two-level) quantum-mechanical system, one of the simplest quantum systems displaying the peculiarity of quantum mechanics. Examples include the spin of the electron in which the two levels can be taken as spin up and spin down; or the polarization of a single photon in which the two states can be taken to be the vertical polarization and the horizontal polarization. In a classical system, a bit would have to be in one state or the other. However, quantum mechanics allows the qubit to be in a coherent superposition of both states simultaneously, a property that is fundamental to quantum mechanics and quantum computing.”

 

This is a simplified explanation of the experiments done by Alain, ,Clauser, and Zeilinger.

https://www.nobelprize.org/prizes/physics/2022/popul-information/

"This progress rests on many years of development. It started with the mind-boggling insight that quantum mechanics allows a single quantum system to be divided up into parts that are separated from each other but which still act as a single unit.

This goes against all the usual ideas about cause and effect and the nature of reality. How can something be influenced by an event occurring somewhere else without being reached by some form of signal from it? A signal cannot travel faster than light – but in quantum mechanics, there does not seem to be any need for a signal to connect the different parts of an extended system."

[swansont]

51 minutes ago, bangstrom said:

This is a simplified explanation of the experiments done by Alain, ,Clauser, and Zeilinger.

https://www.nobelprize.org/prizes/physics/2022/popul-information/

"This progress rests on many years of development. It started with the mind-boggling insight that quantum mechanics allows a single quantum system to be divided up into parts that are separated from each other but which still act as a single unit.

This goes against all the usual ideas about cause and effect and the nature of reality. How can something be influenced by an event occurring somewhere else without being reached by some form of signal from it? A signal cannot travel faster than light – but in quantum mechanics, there does not seem to be any need for a signal to connect the different parts of an extended system."

Bold by me.

You seem to be presenting an alternative view that a signal is needed. And I am asking for details of that signal.

[bangstrom]

9 minutes ago, swansont said:

Bold by me.

You seem to be presenting an alternative view that a signal is needed. And I am asking for details of that signal.

What is the non-alternative view and what kind of "details" are you looking for that I haven't given you already.

If you want more information, why can't you Google that information yourself? The name of the signal is a 'qubit of quantum information'.

[MigL]

I would also like a question answered ...

I brought it up previously, but it was dismissed.
Assume Bob and Alice are in two different frames, separated by large distance.
Bangstrom confidently says that Bob makes the first measurement, and a 'signal' then determines Alice's measurement. 
Special Relativity tells us that there may be a question as to who made the measurement first, as they can only compare their measurements much later.

Is this 'signal' then, frame dependant ?
Does it travel from Bobs frame to Alice's, when he has made the first measurement in his frame ?
And does it travel from Alice's frame to Bob's when she has made the first measurement in her frame ?

This is indeed a 'magical' signal.
Makes one suspend belief in reality between the two measurements.

Which is exactly what we've been telling you !

[swansont]

1 hour ago, bangstrom said:

What is the non-alternative view and what kind of "details" are you looking for that I haven't given you already.

Only you know the details. I’m asking because I don’t know. You keep talking about a signal and an interaction but won’t elaborate. 

1 hour ago, bangstrom said:

If you want more information, why can't you Google that information yourself? The name of the signal is a 'qubit of quantum information'.

I can’t Google it because AFAICT it’s your pet theory, rather than mainstream science. 

[joigus]

1 hour ago, MigL said:

Assume Bob and Alice are in two different frames, separated by large distance.
Bangstrom confidently says that Bob makes the first measurement, and a 'signal' then determines Alice's measurement. 
Special Relativity tells us that there may be a question as to who made the measurement first, as they can only compare their measurements much later.

Is this 'signal' then, frame dependant ?

I'm assuming you mean Alice and Bob are at different points in the same inertial frame?

@Eise introduced a reference to a paper in which the detectors are moving, which would correspond to what you're saying literally. The conclusion seems to be that the projection postulate is weakened by the results.

Let me go back to Alice and Bob being distant, but in the same state of motion. Both Alice and Bob tell nothing to each other about what polarisation direction they're going to measure (that way we guarantee that nothing physical is getting through.) If either Bob or Alice told the other one what they're gonna do, and they can trust each other, that's another matter.

You can even bring to the problem whether Alice trusts Bob --or viceversa. That's nothing to do with the physics of it.

And I'll be "brutally" clear: Can a woman ever trust a man? --if you will.

Alice measures S_x (x-projection of spin.) It produces +.

Question: What can she tell from that?

Answer (think about it, @bangstrom😞 Nothing: Zilch, nothing at all, überhaupt nichts, nada, nada, pues nada.

What has Bob measured? I don't know. In fact, I don't trust him.

What has Bob obtained as a result of his measurement? I haven't the faintest idea.

In a nutshell: Alice needs infinitely many experiments to --at least-- know Bob has (even!!!) performed a measurement.

In fact --I can argue this-- she cant can only tell --after an eternity-- precisely what component of spin Bob has measured.

I'm not sure I'm answering your question, @MigL. 

3 hours ago, bangstrom said:

TIQM is a theory of light. It is essentially the old Wheeler-Feynman absorber theory without the innumerable photons that all-but-one get absorbed.

(My emphasis.)

Truly ignorance is bold and knowledge is reserved --Thucydides. That's all I have to say to your suggesting I'm a novice and you're the "expert" explaining to me how this all works.  

I told you I don't know many details of TIQM --I'm not particularly interested in it--, but building up some makeshift acquaintance with it in order to rebut your WAG assumptions is certainly not much of a challenge. Here:

Quote

The transactional interpretation of quantum mechanics (TIQM) takes the wave function of the standard quantum formalism, and its complex conjugate, to be retarded (forward in time) and advanced (backward in time) waves that form a quantum interaction as a Wheeler–Feynman handshake or transaction.

From: https://en.wikipedia.org/wiki/Transactional_interpretation

The wave function: W-A-V-E  F-U-N-C-T-I-O-N. AFAIK, TIQM is for electrons, protons, neutrons... Any particle that, for some regime, satisfies the Schrödinger equation. It is not a theory of light. It basically purports to be a theory of electrons and the like. I don't think anybody has tried to apply it to anything other than semi-qualitative discussions of quantum paradoxes.

Photons are dealt with, not with quantum mechanics, but with quantum field theory.

The WF theory, OTOH, is a theory of half-advanced, half-retarded classical EM fields, the electrons being classical relativistic particles. It is, therefore, a field theory of light. I forget whether it allows you to give any meaning to radiation reaction and electron self-energy. I think you put it by hand. Am I right? You tell me, you're the expert!! 🤣

QFT is a theory reminiscent of the WF theory in that you have the amplitudes half-advanced, half-retarded, but for all fields: matter fields, and radiation fields.

In every one of these theories, you need to impose boundary conditions to the waves, so the resulting wave is relativistic-causality-compliant and, of course, propagates locally.

In none of these theories could you have, eg, a spherically symmetric solution purely sourcing into (instead of out of) a point. Can you do that with any of them without violating the boundary conditions?

Here, boundary conditions all over it, FYI:

Quote

The transactions "knit together" the various otherwise independent particle wave functions that span a wide range of possible parameter values into a consistent ensemble, and only those wave function sub-components that are correlated to satisfy the conservation law boundary conditions at the transaction vertices are permitted to participate in this transaction formation. The "allowed zones" of Hilbert space arise from the action of transaction formation, not from constraints on the initial offer waves, i.e., particle wave functions.

Again from: https://en.wikipedia.org/wiki/Transactional_interpretation

And all known conservation laws are local --continuity equation. If they're talking about conservation of momentum, energy, and angular momentum and probability density, then it's local to the bone. You're very likely disgracing a theory that's probably much more serious than you make it look.

Now, I can see very easily where you get confused. It's easy if you're clueless about the maths and just follow the words. More from https://en.wikipedia.org/wiki/Transactional_interpretation:

Quote

 

Advances over previous interpretations[edit]

TIQM is explicitly non-local and, as a consequence, logically consistent with counterfactual definiteness (CFD), the minimum realist assumption.^[2] As such it incorporates the non-locality demonstrated by the Bell test experiments and eliminates the observer-dependent reality that has been criticized as part of the Copenhagen interpretation. Cramer states that the key advances over Everett's Relative State Interpretation^[6] are that the transactional interpretation has a physical collapse and is time-symmetric.^[2] Cramer also states that the TI is consistent with but not dependent upon the notion of an Einsteinian block universe.^[7] Kastner claims that by considering the product of the advanced and retarded wavefunctions, the Born rule can be explained ontologically.^[8]

The transactional interpretation is superficially similar to the two-state vector formalism (TSVF)^[9] which has its origin in work by Yakir Aharonov, Peter Bergmann and Joel Lebowitz of 1964.^[10][11] However, it has important differences—the TSVF is lacking the confirmation and therefore cannot provide a physical referent for the Born Rule (as TI does). Kastner has criticized some other time-symmetric interpretations, including TSVF, as making ontologically inconsistent claims.^[12]

Kastner has developed a new Relativistic Transactional Interpretation (RTI) also called Possibilist Transactional Interpretation (PTI) in which space-time itself emerges by a way of transactions. It has been argued that this relativistic transactional interpretation can provide the quantum dynamics for the causal sets program.^[13]

 

(My emphasis.) Wow! So it is non-local. Or is it? @bangstrom wants it badly, for some reason, but no. Hold your horses Mr. "expert." What do you find when you click on the magic words "non-local"? (Wikipedia again) This:

Quote

In theoretical physics, quantum nonlocality refers to the phenomenon by which the measurement statistics of a multipartite quantum system do not admit an interpretation in terms of a local realistic theory. 

Which, as discussed ad nauseam, is only because quantum mechanics is essentially, undoubtedly, unmistakably non-realistic. Not because it is non-local in any way. You keep getting starry-eyed by these words "non-local." Do you not understand the implications of the Kochen-Specker theorem? (Rhetorical question.)

QM is local.

Gell-Mann has told you so.

Feynman has told you so.

Coleman has told you so.

Zeilinger has told you that he prefers "non-realistic" to "non-local" --thanks to @Eise

Hossenfelder has told you so.

Swansont has told you so.

MigL has told you so.

Eise has told you so.

I have told you so.

Take care,

Joigus

 

 

Edited October 12, 2022 by joigus
minor addition

[MigL]

2 hours ago, joigus said:

I'm not sure I'm answering your question, @MigL. 

I probably wasn't very clear.
But I found this reference on Wiki which explains better than I did ...

"The distance and timing of the measurements can be chosen so as to make the interval between the two measurements spacelike, hence, any causal effect connecting the events would have to travel faster than light. According to the principles of special relativity, it is not possible for any information to travel between two such measuring events. It is not even possible to say which of the measurements came first. For two spacelike separated events x₁ and x₂ there are inertial frames in which x₁ is first and others in which x₂ is first. Therefore, the correlation between the two measurements cannot be explained as one measurement determining the other: different observers would disagree about the role of cause and effect.

(In fact similar paradoxes can arise even without entanglement: the position of a single particle is spread out over space, and two widely separated detectors attempting to detect the particle in two different places must instantaneously attain appropriate correlation, so that they do not both detect the particle.)"

From       Quantum entanglement - Wikipedia

Edited October 12, 2022 by MigL

[bangstrom]

5 hours ago, swansont said:

Only you know the details. I’m asking because I don’t know. You keep talking about a signal and an interaction but won’t elaborate. 

I can’t Google it because AFAICT it’s your pet theory, rather than mainstream science. 

The timing between the signal and its reception is instant. There is no time or observation to be made between the signal and sink so there is nothing to elaborate upon.

I would like to claim prescience for finding a violation of of Bell’s inequality, for demonstrating non-locality and for the details of signaling by qubits of quantum information but unfortunately the three winner’s of this year’s Nobel prize have the preponderance of evidence that they thought of it first with their experiments.

You may not be able to Google my pet theory but you can Google about why the three won this year.

5 hours ago, joigus said:

 

Truly ignorance is bold and knowledge is reserved --Thucydides.

Is that why you are so reserved?

5 hours ago, MigL said:

I would also like a question answered ...

I brought it up previously, but it was dismissed.
Assume Bob and Alice are in two different frames, separated by large distance.
Bangstrom confidently says that Bob makes the first measurement, and a 'signal' then determines Alice's measurement. 
Special Relativity tells us that there may be a question as to who made the measurement first, as they can only compare their measurements much later.

Is this 'signal' then, frame dependant ?
Does it travel from Bobs frame to Alice's, when he has made the first measurement in his frame ?
And does it travel from Alice's frame to Bob's when she has made the first measurement in her frame ?

This is indeed a 'magical' signal.
Makes one suspend belief in reality between the two measurements.

Which is exactly what we've been telling you !

Sorry, I didn't comment on your statement with so much going on at the time. You may be surprised that I agree with what you said.

This is for both you and Joigus since he asked the same question.

We know from SR that a spacelike separation is one second of time for every 300,000 km of distance.

If the spacelike timing in an experiment is exactly the same from both locations, it is impossible to tell which came first based on that information because the two events are simultaneous. The only way to tell which came first is to ask the experimenter which end of the events they measured first. If the experimenter says they measured Bob’s end first, then Bob’s end was measured first. The experimenter is the only one making observations. Alice and Bob are imaginary so, in reality, neither one can measure anything.

The numerical value for a spacelike timing and the speed of light are exactly the same, so the calculations using the value of c are the same no matter what we choose to call it. It also means that, if the time of a space-like signal between the two events when measured from both ends is is equal, the signal time was instant.

The calculations remain consistent with SR with the one exception being the wording of the second postulate that nothing can travel faster than light.

An instant signal is "magical" which is why Einstein called it, "spooky" and Zeilinger called it "eerie" but a non-local signal by quantum entanglement has been repeatedly demonstrated as real. That is why it has caused so much attention.

An instant non-local signal may be real at the quantum level but we can only view the timing between two points separated by space as 'space-like' which makes it impossible to use quantum signaling for FTL communication.

[joigus]

1 hour ago, bangstrom said:

If the spacelike timing in an experiment is exactly the same from both locations, it is impossible to tell which came first based on that information because the two events are simultaneous.

In what frame are they simultaneous? For spacelike separated events, simultaneity relations depend on the observer, as you should know. And now I understand that's what @MigL was trying to say. IOW simultaneity is frame-dependent.

1 hour ago, bangstrom said:

The only way to tell which came first is to ask the experimenter which end of the events they measured first. If the experimenter says they measured Bob’s end first, then Bob’s end was measured first. The experimenter is the only one making observations. Alice and Bob are imaginary so, in reality, neither one can measure anything.

No. Alice and Bob are not imaginary. They are detectors. Don't dodge the question.

[swansont]

8 hours ago, bangstrom said:

The timing between the signal and its reception is instant. There is no time or observation to be made between the signal and sink so there is nothing to elaborate upon.

I would like to claim prescience for finding a violation of of Bell’s inequality, for demonstrating non-locality and for the details of signaling by qubits of quantum information but unfortunately the three winner’s of this year’s Nobel prize have the preponderance of evidence that they thought of it first with their experiments.

You may not be able to Google my pet theory but you can Google about why the three won this year.

Yes, I can, but as you quoted from the Nobel description, “in quantum mechanics, there does not seem to be any need for a signal to connect the different parts of an extended system.”

Your position is the opposite of that. What this signal of yours is, only you can say. But you don’t.

[Ghideon]

17 hours ago, bangstrom said:

This is a simplified explanation of the experiments done by Alain, ,Clauser, and Zeilinger.

https://www.nobelprize.org/prizes/physics/2022/popul-information/

Correct link: The Nobel Prize in Physics 2022 - Popular science background - NobelPrize.org

The advanced information might be of interest: The Nobel Prize in Physics 2022 - Scientific background - NobelPrize.org. The document gives some historic background, describes experimental setups, mathematics. It comments on what realist and local means in the perspective of the prize.

Quote

... all attempts to construct a local realist model of quantum phenomena are doomed to fail. Bell used the words local and realist here in a technical sense: the former indicates the impossibility of instantaneous signalling, limited by the finite speed of light, and the latter means that the outcome of any experiment is fully determined by properties of the system, often referred to as hidden, that exist independently of any actual or potential measurement

Note: I find no support in the paper for any "faster than light" or "instant signals".  The paper is focused on the science behind establishing the violation of Bell inequalities.

Edited October 12, 2022 by Ghideon
missing sentence added

[bangstrom]

5 hours ago, swansont said:

Yes, I can, but as you quoted from the Nobel description, “in quantum mechanics, there does not seem to be any need for a signal to connect the different parts of an extended system.”

Your position is the opposite of that. What this signal of yours is, only you can say. But you don’t.

If you have a particle A and a particle B a considerable distance apart. The quantum properties of A are are said to be in superposition with particle B as long as the two are entangled. If you observe any one property of either A or B, the Bell test tells us that the observed properties are perfectly random.

The Bell test is a statistical test and it is difficult to explain but explanations are easy to find and not terribly difficult to follow. So, for now, just assume the Bell test is correct and the and the quantum properties of entangled particle are random.

If you observe a single particle, for example, observe particle A for spin direction, it can be observed as either spin-up or spin-down but the spin orientation before it is observed is perfectly random. If the spin of particle A is observed to be spin-down that means the entanglement with particle B is broken so the quantum properties of B are now fixed and no longer random.

We know that, if the spin of particle A is spin-up, the spin of particle B must be spin-down unless something happens to disturb particle B after the loss of entanglement. But, as long as particles A and B are entangled their quantum properties are anti-correlated.

This is all basic stuff of QM that has been known for many years and well described in many sources.

Now to answer your question. If particle A is spin-up, particle B must be spin-down when entanglement is lost. The question is, "How does particle B 'know' it should should be spin-down and when did it 'know' it? There must have been some message to the wave function that kept the two particles anti-coordinated while entangled.

It could be a light speed a signal that maintained anti-correlation, in which case, the spin of particle B could be observed as either spin-up or spin-down when observed since the quantum properties of entangled particles are random until observed

The light speed hypothesis has been tested by observing the the spin of the unobserved particle B before a light speed signal had time to reach B and let it 'know' that particle A has been observed as spin-up so now it should be spin-down. 

This is where something superluminal is happening.

Again, this is all old news and forests have been destroyed to explain how it works.

[joigus]

1 hour ago, bangstrom said:

If the spin of particle A is observed to be spin-down that means the entanglement with particle B is broken so the quantum properties of B are now fixed and no longer random.

Lesson number 1 in quantum mechanics:

The quantum properties of B are not fixed. They're sure to produce the previous result if you happen to measure the same projection of spin. If you measure another projection of spin, they're completely random (equally likely to give + or -) and, in this case totally uncorrelated with the other particle's values.

I told you, "random" doesn't mean much in itself. Give me a probability distribution. Have you ever heard of Bertrand's circle paradox?

I propose the game of spotting your most embarrassing mistakes in each of your entries. It would be a fun game.

There's no other interest in this thread now.

Edited October 12, 2022 by joigus
minor rephrasing

[swansont]

1 hour ago, bangstrom said:

Now to answer your question. If particle A is spin-up, particle B must be spin-down when entanglement is lost. The question is, "How does particle B 'know' it should should be spin-down and when did it 'know' it? There must have been some message to the wave function that kept the two particles anti-coordinated while entangled.

This is a view of the situation, but isn’t actually part of the QM. As has been pointed out, this is a classical interpretation, and it isn’t classical physics.

1 hour ago, bangstrom said:

It could be a light speed a signal that maintained anti-correlation, in which case, the spin of particle B could be observed as either spin-up or spin-down when observed since the quantum properties of entangled particles are random until observed

The light speed hypothesis has been tested by observing the the spin of the unobserved particle B before a light speed signal had time to reach B and let it 'know' that particle A has been observed as spin-up so now it should be spin-down. 

This is where something superluminal is happening.

Only if you insist that a signal is sent.

1 hour ago, bangstrom said:

Again, this is all old news and forests have been destroyed to explain how it works.

But you insist that it works a particular way, and there’s no substance to that argument. 

 

 

 

[bangstrom]

8 hours ago, Ghideon said:

Correct link: The Nobel Prize in Physics 2022 - Popular science background - NobelPrize.org

The advanced information might be of interest: The Nobel Prize in Physics 2022 - Scientific background - NobelPrize.org. The document gives some historic background, describes experimental setups, mathematics. It comments on what realist and local means in the perspective of the prize.

Note: I find no support in the paper for any "faster than light" or "instant signals".  The paper is focused on the science behind establishing the violation of Bell inequalities.

The “faster than light” and the “instant signals” parts go by different different names such as ‘spooky action action at a distance’ or ‘non-locality, or ‘instant interaction’ .

The violation of the Bell test rules out the possibility of classical ‘hidden variable” explanations for the above examples above that are permitted by quantum physics but not classical.

If the three Nobel winners had discovered that the observations of their experiments invalidated the possibility of instant action at a distance and that this was a non-real artifact of classical physics, there would be nothing remarkable about their discoveries.

The disappointing part of their discoveries is that the remarkable parts are only possible at the quantum level and are so far of little use for macro level for such things as FTL communication or Star Trek style teleportation. The exceptions may be for high speed quantum computing and for computer encryption.

1 hour ago, joigus said:

The quantum properties of B are not fixed.

The properties of B are random not fixed prior to the first observation. The observation of particle A fixes the observed property B as anti-correlated to that of A. If A and B were both random they would not necessarily be anti-correlated.

51 minutes ago, swansont said:

This is a view of the situation, but isn’t actually part of the QM. As has been pointed out, this is a classical interpretation, and it isn’t classical physics.

This is not classical because the quantum properties are not fixed from the start. Do you remember the gloves in boxes thought experiment that didn’t work with QM. The violation of the Bell test ruled out the possibility that the quantum properties are fixed from the start.

56 minutes ago, swansont said:

Only if you insist that a signal is sent.

The instant loss of entanglement on both ends is the signal.

 

[MigL]

3 hours ago, bangstrom said:

There must have been some message to the wave function that kept the two particles anti-coordinated while entangled.

You are considering the entangled particles and the wave function to be separate entities.
They are not.
Before the 'first' spin detection of the particle that fixes the spin orientation of the second particle, while entanglement persists, there are no particles, just their common wave function.
That is what is meant by 'abandoning local realism'.

 

As for my previous question and Wiki quote, I notice you again read just the parts that suit your narrative.
The pertinent part was

21 hours ago, MigL said:

It is not even possible to say which of the measurements came first. For two spacelike separated events x₁ and x₂ there are inertial frames in which x₁ is first and others in which x₂ is first. Therefore, the correlation between the two measurements cannot be explained as one measurement determining the other:

If you can't know which comes first, how can you determine which sends the 'magical' signal to the other ?
Do they both ?
Does neither ?

This 'magical' signal is becoming more and more like the 'aether'.
So many conflicting properties, no evidence, and definitely not needed.

Edited October 12, 2022 by MigL

[swansont]

1 hour ago, bangstrom said:

The instant loss of entanglement on both ends is the signal.

And we’ve come full circle again. Same claim, no physics to back it up.

[bangstrom]

4 hours ago, MigL said:

You are considering the entangled particles and the wave function to be separate entities.

Where did you get that crazy idea.

4 hours ago, MigL said:

Before the 'first' spin detection of the particle that fixes the spin orientation of the second particle, while entanglement persists, there are no particles, just their common wave function.
That is what is meant by 'abandoning local realism'.

 

Abandoning local realism involves abandoning the principle that all local change must be mediated by a direct physical connection.

Abandoning the principle of realism involves abandoning the principle that we live in an objective reality.

Abandoning the idea that two entangled particles connected by a common wave function in which there are no particles is what meant by abandoning common sense.

4 hours ago, MigL said:

It is not even possible to say which of the measurements came first. For two spacelike separated events x₁ and x₂ there are inertial frames in which x₁ is first and others in which x₂ is first. Therefore, the correlation between the two measurements cannot be explained as one measurement determining the other:

I have explained this several times before and it is so simple it should need no explanation. The observers at the opposite ends of the experiment have absolutely no way of knowing which measurement came first until later when they can later gather their information together.

But it is possible to say which came first before that. Just ask the experimenters which observation they chose to measure first.

3 hours ago, swansont said:

And we’ve come full circle again. Same claim, no physics to back it up.

The repeated observation that entangled particles are anti-correlated when they drop out of entanglement suggests that the entanglement must have been signaled or at least maintained by some sort of information that that kept the particles anti-correlated throughout the entanglement.

For example, when two particles A and B are entangled even though they might be light years apart. A measurement made on either one of the entangled particles instantly destroys the entanglement for both of the entangled particles and their quantum properties which were indeterminate before (superimposed) instantly become determinate.

This observation suggests that there must be some sort of wavelike connection between the two remote particles that maintained their their quantum properties as anti-correlated and even though the two particles may have been out of range of a light speed signal at the instant when their entanglement was lost.

With the loss of entanglement (decoherence) the previously unobserved particle somehow instantly 'knew' a quantum property of its entangled partner had been observed and it presented a similar quantum property that was anti-correlated
to the newly presented property of its former partner. This suggests some form of a non-local exchange of quantum information often called a 'signal'.

[Eise]

4 hours ago, bangstrom said:

But it is possible to say which came first before that. Just ask the experimenters which observation they chose to measure first.

It seems that you also do not understand special relativity. There is no preferred frame of reference. So in space-like separated events, there will be an observer for whom Alice's measurement occurred before Bob's, and also an observer for whom Bob's measurement was before Alice's. The frames of reference of the source, or of Alice or Bob simply are not  preferred frames of reference, because there are none. I thought MigL was very clear about it, and I also brought this point when I referred to this Geneva experiment the first time, but it seems you do not understand it.

[bangstrom]

5 minutes ago, Eise said:

It seems that you also do not understand special relativity. There is no preferred frame of reference. So in space-like separated events, there will be an observer for whom Alice's measurement occurred before Bob's, and also an observer for whom Bob's measurement was before Alice's. The frames of reference of the source, or of Alice or Bob simply are not  preferred frames of reference, because there are none. I thought MigL was very clear about it, and I also brought this point when I referred to this Geneva experiment the first time, but it seems you do not understand it.

I forgot to mention that Alice and Bob are assumed to be in the same local, inertial reference frame. We can choose a local reference frame, but of course, I understand there is no preferred reference. That is basic.

Perhaps you got confused by my mention of space-like time. If an event happens at at one time, and another event happens the next day, the clock timing of the two events is called 'time-like.'

However, if two events happen at exactly the same time. Say, one event happens on the moon and another event happens on Earth, the time-like separation between the two is zero because they are simultaneous but we know from SR that there is an observed space-like clock time separation of about one second for every 300,000 km of distance. This has nothing to do with the lack of a universal frame of reference.

If Alice and Bob share the same inertial reference frame, the space-like time between the should be exactly the same for both. 

With space-like time, near events are only a short distance away in both space and time (spacetime) but remote events are farther away in space and time. There is a name for that observation and it is space-like time.

Are you saying that is what I don't understand about the experiments?

[Ghideon]

10 hours ago, bangstrom said:

The disappointing part of their discoveries is that the remarkable parts are only possible at the quantum level and are so far of little use for macro level for such things as FTL communication or Star Trek style teleportation. The exceptions may be for high speed quantum computing and for computer encryption.

I don't find it disappointing, it is just a trivial consequence of the experiments? The experiments were not intended to falsify special relativity, the experiments were based on the assumption that SR is correct. 

Quote

Like all theoretical results, Bell inequalities are derived under certain assumptions. One of these was of particular concern to Bell himself: the assumption that the two observers, Alice and Bob, make random choices of what to measure independent of each other.

For this to be true, one must make sure that Alice cannot send a message to Bob about whether A1 or A2 is measured, which Bob receives before he decides to measure B1 or B2. In other words, Alice will not influence Bob’s choices. Assuming that special relativity is correct, this locality condition amounts to making sure that such a message would have to travel with a speed greater than that of light. There are also some other assumptions that we shall briefly discuss in a later section.

(bold by me) https://www.nobelprize.org/uploads/2022/10/advanced-physicsprize2022.pdf