bangstrom

1 hour ago, swansont said:

Argument from incredulity is a fallacy, though, and carries no weight.

Co-opting terminology is just bad form. “signal” has to mean the same thing for everyone. There is no signal- no interaction - between the entangled particles. 

 

The anti-correlation among entangled particles is evidence of something superluminal happening. This is not explained by the argument from incerdulity that there is no signal.

13 hours ago, Eise said:

Nope. Correlation (consistently, not accidentally) means that the events share a common history. And that is the moment that the entangled particle were produced.

Correlation means the particles are matched together in their quantum properties, in the case of entanglement, they are kept opposite, that is, anti-coordinated. Any one quantum property measured before entanglement need not be the same after entanglement is lost. This requires some form of instant transaction of information.

30 minutes ago, studiot said:

You didn't reply to my last post, but I will try this anyway.

I read the your post, the book looked good, I took note of the book, but I don’t have the book. Perhaps sometime later I will have something to say.

33 minutes ago, studiot said:

Consider the equation sinx = 0.866...

No one is suprised when we say that the solution to this equation is x = 60^o or x = 120^o or x = 420^o or  a further infinity of solutions.

So are all these solutions in superposition or entangled, and just waiting to be selected or observed ?

No one is surprised with the math but here is the surprising part. If you measure the polarity of a local entangled photon as 60 degrees, you instantly know the polarity of the other photon should be 105 degrees. The other photon could be miles away or theoretically many galaxies away. The question is, How did the distant photon instantly 'know' what its orientation should be?

On 10/27/2022 at 7:02 AM, swansont said:

No, it’s not. It’s assumed by you, but it’s not a falsifiable assumption. Much like EM waves were not evidence of an aether. Science requires evidence to back up such claims.

There is no interaction in the theory. It’s assumed because of classical physics preconceptions

You are right, the signal is an assumption based on classical preconceptions so we need to take that into consideration. Somehow entangled particles appear to ‘see’ no separation between them, in which case, there is no need for a signal. The quantum explanation is that their properties are superimposed and I don’t find that very satisfactory either. I consider the ‘signal’ to be a placement word for what is behind the changes we observe.

The trouble with all of our assumptions is that over time they eventually over take on an undeserved reality and become unquestionable facts.

On 10/27/2022 at 7:02 AM, swansont said:

Nobody has disagreed that the states are undetermined. Everyone has confirmed it.

You know, I know and everyone knows that entangled states are indeterminate. What everyone doesn’t know is that the indeterminacy of entanglement is what makes it possible.

2 hours ago, Eise said:

10 hours ago, bangstrom said:

"The viewpoint of most physicists is that the violation of Bell's inequality shows us that quantum mechanics is non-local."

So your claim is that Zeilinger considers QM to be local. My claim is the opposite.

Yep. Read, and understand the paragraph after the one where your citation comes from. Your claim is false.

Your interpretation may be correct but the paragraph itself is false. Look at the context from which it came.

Both of our quotes come from a part of the book where Zeilinger is speculating about different possibilities listing the pros and cons of each one without really taking sides so it is hard to tell which of the mentioned views he favors.

Read the introductions.

Zeilinger says,“We now discuss some of the possible conceptual consequences of the breakdown of local realism.”

Here are the intros,

“One possibility is that the reality assumption is not correct.”

“Another possibility would be that the locality hypothesis is not correct.”

My quote in the series began, “ Nearly all physicists agree that the experiments have shown that local realism is an untenable position.”

Your quote began, “The other possibility would be for us to give up the picture of a world that exists in all its properties independent of us. That would mean that we have a very essential influence on reality just by deciding which measurement to perform.”

As I said, Zeilinger later tested the above possibility with his two quasar experiment and found it to be false so I don’t consider that paragraph to be an indicator of Zeilinger’s views no matter how it is interpreted.

2 hours ago, Eise said:

There is a better word: correlation!

Correlation between distant points and under varying conditions requires some form of signaling. Violations of Bell's ineqalities and Zeilinger's teleportation rule out the possibility that particle's quantum properties are not unchanged from the start.

2 hours ago, Eise said:

OMG! Two cars colliding is a single event. Two measurements are two events. Two measurements that are space-like separated do not have the same timely order in all inertial frames. This comparison is BS.

Entangled particles act as if they are side-by-side so any action on one end instantly affects the other as a single event. There is no space-like separation at the particle level, in the way there is at the macro level, so all interactions are essentially instant at the particle level for entangled particles. 

In answer to your question, this is my view of realism:

Realism accepts that the cause of a physical change must be local in that it requires a physical interaction between a cause and effect. It also accepts that objects are real and exist in our physical universe independent of our minds. We live in an objective reality, not one which exists only in our minds or which takes form only upon our looking at it.

3 hours ago, Eise said:

And still you have not been able to cite even one recent text, where a QM specialist argues that we must give up on locality. Yes, you'll find popular science books in which such is stated, and, even worse, standard QM text books that say such things (read the Coleman article again, and try to understand it!). 

On further reading I am open to the possibility that instant action at a distance is 'local' since everything is instant and local for entangled particles and there is no space-like timing between them. I have always considered the emission and absorption of light to be simultaneous events from the perspective of light itself.

As Carver Mead explains, every electron, when the resonant conditions between permit, is capable of a direct interaction with any other electron on the same Minkowski light cone. I can understand that kind of locality but I don't recognize it as the same locality discussed here.                                                                                                                                                                                                                          
 

4 minutes ago, joigus said:

Here's a riddle for you: If there's no way to know which "action" came first --in a given frame of reference--, how do you know the time interval between the "actions" can tagged as FTL?

That is how it is done. Make the measurements to the far left and far right so close together that there is no way of knowing which came first and see if they are still anti-coordinated. If one particle is measured as spin up, how long does it take for the other particle to 'know' it should be measured as spin down. There is no need to know which came first when measuring just the times.

Tests such as Bell's and other experiments have determined that a single observed quantum property of either member of an entangled pair is random before observed, and when observed, the particles are anti-coordinated. 

If the quantum properties are not fixed from the start but always anti-coordinated, that implies that there must be a signal between the particles that keeps them anti-coordinated either at all times or at the instant of the first observation.

Keeping the measurements short and the distance between measurements great allows a comparison between the signaling speed and light speed. The speeds have been measured to be far in excess of light speed. 

The most dubious part of this experiment is that it assumes that the particles have not kept their same anti-coordinated quantum properties since the start, in which case, no signaling would be required.

This is where Zeilinger's experiments with teleportation become important. Zeilinger demonstrated that a second pair of entangled particles can be generated and entangled with the first pair creating a three way entanglement. By measuring the identity of the free particle from the second entanglement, this instantly fixes the properties of all the entangled particles including the first pair. 

Zeilinger's set-up is not complicated but it is hard to explain. It demonstrates that a single observation of a second entanglement can instantly swap the quantum properties of the first entanglement, in which case, the assumption is valid that the quantum properties need not be fixed from the start and they can change in an instant while remaining anti-correlated. This requires some form of instant signaling among entangled particles.

55 minutes ago, swansont said:

The correlations are confirmed, but you have presented no evidence of a signal. You just assume it’s there. But repetition of the claim is not evidence.

Observing a single property of one particle of an entangled pair instantly fixes the same property of the entangled partner.

This is evidence of some form of signaling.

The possibility that the properties were necessarily the same from the start has been ruled out as I just explained...again.

31 minutes ago, joigus said:

Non-realism is just the character of QM. So it's not "we don't need it." It's what it's like.

That is right, but for me, non-locality is what makes realism a -non.

35 minutes ago, joigus said:

It's what it is. A non-realistic theory out and out. OK?

OK, by me.

37 minutes ago, joigus said:

The double-slit experiment has no entanglement, and already tells you that much.

I would disagree but what is that 'something in the environment' that tells the photon how many slits to respond to and where to land. As Wheeler and Feynman and later Cramer concluded, there must be a signal propagating forward and backward in time to initiate the transition of energy.

48 minutes ago, joigus said:

I know you don't like my objections, but I'm here again.

A day without your objections is like a day without sunshine. I am worried when we agree.

1 hour ago, MigL said:

If you wish to pursue the non-locality idea, you had better come up with a solid theory as to what this non-local signaling' entails.
How it is transmitted superluminally.
How it violates relativity, especially SR, in deciding which interaction comes first to cause the other.
And many more.

The 'signal', for the lack of a better word, is measured by clocks synchronized as closely as possible, and the times are observed to be much to fast to measure and far in excess of luminal speed. The explanation is as someone once said, Einstein does not tell God what to do.

I don't find that it violates SR except for the second postulate and possibly not even that.

If it is possible to choose or determine which action came first- then we know which action came first. If we don't know which came first, we simply don't know or usually even care which came first. In SR, if two cars collide is it necessary to know which collided first? Can you explain why this is a even a problem?

8 minutes ago, MigL said:

Non-realism and non-locality achieve the same results in explaining QM effects like entanglement.
Yet you agree that we have no realism.
So why do we need non-locality, if we already have non realism to explain the behavior ?

This is an excellent two-part question, one part of which I have explained again and again because it was ignored again and again. I can explain it later...again if anyone cares... except to add that non-locality violates realism. Non-locality is an exception to realism since it is something we never observe at the macro level which is why we have magic shows.

Non-locality itself is a violation of realism so we have no need for non-realism as an explanation for the effects of entanglement.

The second half of the question is for someone else to answer. If we have non-realism as an explanation for QM effects how does that work without non-locality?

8 hours ago, Eise said:

Nope. You cannot read. Or intentionally interpret it wrong. He is very clear about it, that his stance is another one than 'most physicists' (in 2010), again the same citation:

What a mess, we both read the same thing and come up with opposite interpretations. Just for clarification, you are saying here that Zeilinger is not with "most physicists" in saying QM is non-local.

"The viewpoint of most physicists is that the violation of Bell's inequality shows us that quantum mechanics is non-local."

So your claim is that Zeilinger considers QM to be local. My claim is the opposite.

8 hours ago, Eise said:

In clear text for you: it is not possible to speak about all properties of a particle, or a pair of entangled particles, before they are measured. That is what is meant by realism. And if we give up on realism, we do not have to give up on locality. And QM does not need none-localism.

l agree it is not possible to speak about the properties of particles before they are measured. Minor point, the properties are not a part of our 'reality' until they are measured.  And again you are saying QM is local. " does not need none-localism."

9 hours ago, Eise said:

Why going on a side track? We are not discussing superdeterminism here. 

I see the main disagreement here to be about Zeilinger's, and "most physicists" view about QM. You say the views are that QM is local and I say the views are that QM is non-local. Does that simplify it?

Also everyone agrees that realism. local or not, is violated.

1 hour ago, Ghideon said:

As far as I can tell experimental observation of non-locality is not part of the motivation of the prize*, I do not understand the question, sorry. I do not see the reference I asked for so I assume it's your personal interpretations. 

Yes, it is my very own personal opinion that the one thing behind the experimental observations that sets them apart from the ordinary is their application of non-local entanglement in all of their experiments. That is what made them Nobel winners.

1 hour ago, Eise said:

14 hours ago, bangstrom said:

If you have read and understood Zeilinger you should know that he did not support realism but he strongly supports non-locality.

A blatant lie.

Your out of context citation of Zeilinger:  

Zeilinger is a strong supporter of non-locality and he also rejects local realism. You won't find any quotes in your book to the contrary. On p. 60, Zeilinger says his Ph. D. dissertation was about testing non-locality over large distances.

2 hours ago, Eise said:

Here is a quote from Anton Zeilinger's book.

" Nearly all physicists agree that the experiments have shown that local realism is an untenable position. The viewpoint of most physicists is that the violation of Bell's inequality shows us that quantum mechanics is nonlocal. This nonlocality is exactly what Albert Einstein called "spooky"; it seems eerie that the act of measuring one particle could instantly influence the other one." From "Dance of the Photons" p. 286

Take time to read your quote. The first sentence says,"Nearly all physicists agree that the experiments have shown that local realism is an untenable position."

OK, local realism is untenable and you can include Zeilinger as one of the,"Nearly all physicists."

Next part:

"The viewpoint of most physicists is that the violation of Bell's inequality shows us that quantum mechanics is nonlocal. This nonlocality is exactly what Albert Einstein called "spooky"; it seems eerie that the act of measuring one particle could instantly influence the other one."

Here Zeilinger says, the viewpoint of most physicists is that QM is non-local. I am sure Zeilinger includes himself among the "most physicists".  Zeilinger rejects local-realism but accepts non-locality just as I have been claiming. Nicht wahr?

2 hours ago, Eise said:

On 10/6/2022 at 12:43 PM, Eise said:

Ok, back to business: I found a pdf of Zeilinger's book. This is the paragraph immediately after the paragraph bangstrom cited:

Quote

The other possibility would be for us to give up the picture of a world that exists in all its properties independent of us. That would mean that we have a very essential influence on reality just by deciding which measurement to perform.There are indeed hints that this might be the message we have to accept. The most significant result in that connection is the so-called Kochen-Specker paradox.It would go too far to explain it in detail here. A brief mention of the result must suffice. The Kochen-Specker paradox can be stated rather easily. It says that even for individual quantum systems, if they are sufficiently complex, it is not possible to assign to them elements of reality that explain all possible experimental results independent of the full experimental context, i.e. which measurement is performed at the same time on the same system. Now, since Kochen and Specker only considered measurements on single quantum particles, the locality hypothesis does not come into play.

Expand  

In the latter part of the book Zeilinger listed several alternative views to his own that could explain the results of his experiments. Your quote above is one of those alternative views. To quote,"The other possibility would be for us to give up the picture of a world that exists in all its properties independent of us. That would mean that we have a very essential influence on reality just by deciding which measurement to perform."

This possibility has a recent history. Zeilinger et al. devised an experiment to test the possibility that an experimenter's choice of which measurements to perform could affect the results of an experiment as if by 'wishful thinking'.

As I recall, they decided upon some types of Wheeler's delayed choice experiments and let a computer randomly decide which one to run. Someone complained that a computer could also be responding an experimenter's 'wishful thinking' so they decided to let the colors of the first photons from an extremely distant galaxy tell the computer which tests to run. The galaxy would decide which measurements to be made at one end of the experiment and another galaxy far from the first would decide which measurements would be made at the end.

They found statistically that choices made by distant galaxies gave the same results as when the choices were made by the experimenters so the hypothesis above was busted.

13 hours ago, Ghideon said:

I can't find support for that in official statements*; can you provide a link? Or is it your interpretation of the experimental results?

(The short official reason* is: "for experiments with entangled photons, establishing the violation of Bell inequalities and pioneering quantum information science")

I am sure the statement from the Royal Swedish Academy is as good as it gets for information but why, except for the experimental observation of non-locality, is anything the prize winners discovered worthy of a Nobel?

Entangled photons demonstrate, as described in John Cramer’s transactional interpretation, that two photons are part of the same direct interaction between emitter and absorber moving both forward and backward in time as described by Wheeler and Feynman. Their transactions are non-local at the quantum particle level but local in our space-time view of the same events.

The violation of Bell’s inequalities demonstrates the reality of the non-local interactions among remote particles having no direct physical contact between them. This is what Einstein called ,”Spooky action”. The violation of Bell’s inequalities also ruled out the possibility hidden variables in the environment that might serve as an alternate explanation for non-locality.

As for pioneering quantum information science, the instant, non-local nature of signals among electrons holds promise for smaller and much faster computers as well as secure means for encryption of EM signals and instant detection if a signal has been hacked.

The one thing that all three of these discoveries have in common is that non-locality sets their experimental results apart from the classical physics of EM signals. Take away the non-locality and they have discovered nothing new.

On 10/24/2022 at 3:17 AM, Eise said:

On 10/21/2022 at 6:55 PM, bangstrom said:

The three Nobel prize winners won their laurels for demonstrating the reality of non-locality- aka "spooky action at a distance".

Nope. They showed that at least one of both, locality or realism is not valid. All my bulleted authors above say, or tend to, give up on realism, especially Zeilinger himself.  

Why do you say they did not demonstrate non-locality. That was what was so remarkable about their discoveries and the discovery of non-locality is what most clearly violates locality and realism.

9 hours ago, Eise said:

On 10/24/2022 at 10:52 AM, bangstrom said:

As for realism, I say realism is dead

Only after you redefined realism to contain locality. Zeilinger and your IBM lady are very clear: 2 distinct assumptions flow into the CHSH inequality: realism and locality. In this whole thread you were defending that we should give up on locality. And now you are saying that instead we should give up on realism??

 

This is a serious misunderstanding if you think it is an EITHER-OR binary choice. I explained that realism AND locality are BOTH violated. If you go to Paris and find that the Leaning Tower has instantly swapped places with the Eiffel tower (entangled particles can do this) that would be a non-local event as well as violations of BOTH locality and realism.

If you have read and understood Zeilinger you should know that he did not support realism but he strongly supports non-locality. Realism and locality are not mutually exclusive. Non-locality violates realism and I think that should be obvious.

8 hours ago, joigus said:

15 hours ago, bangstrom said:

Do you still claim that the violation of realism does not invalidate Einstein's view of realism?

As I never claimed that, there is no way that I might still claim that.

Einstein's view of realism is untenable today.

However, Einstein's original argument was about space variables.

But spin cannot be understood in terms of space variables. In fact, spin variables cannot even be consistently understood as coming from any internal reality based on commuting variables, or "just parameters." Period.

Why don't you read what people say, draw conclusions carefully, are rigorous about what you say yourself, and stop offending?

There is a statement by Einstein often referred to as the EPR Criterion of Reality:

“If, without in any way disturbing a system, we can predict with certainty (i.e., with probability equal to unity) the value of a physical quantity, then there exists an element of reality corresponding to that quantity.”

MigL said on Sept 9, “Say I take a pair of gloves, and put one in one sealed box, and the other in another sealed box. I give you one box and a plane ticket to Australia, and the other box to Joigus. Neither of you knows which glove is in your box.
When you get to Australia, you open the box, and find a right-handed, or left-handed glove.”

As soon as you've done that, you immediately know the handedness of the glove in Joigus' box, as they are correlated by pairing.

No information transferred, and the only 'black boxes' are the ones that held the gloves.”

This fits Einstein’s “Criterion of Reality” like a glove where you have an undisturbed system with predicted certainty and you appeared to endorse this point of view.

You said of Sept. 12 “Go back to the example of the gloves that MigL was talking about. One glove goes to Australia and the other stays with me. I open the box and find out that it's LH. I thereby know immediately that hoola got the RH one. Would you think for a moment that one glove corresponds to the right hand and the other to the left hand because some "spooky action at a distance" has taken place between them? That's what's foolish to say. The gloves are perfectly anti-correlated just because the correlation was there from the beginning. “

That sounds like an endorsement of Einstein’s reality where you have an undisturbed system with a predictable element of reality, “because the correlation was there from the beginning.” Perhaps instead of asking about Einstein’s reality I should have asked if you still adhere to the gloves in boxes scenario.

7 hours ago, Eise said:

On 10/21/2022 at 6:55 PM, bangstrom said:

he three Nobel prize winners won their laurels for demonstrating the reality of non-locality- aka "spooky action at a distance".

Nope. They showed that at least one of both, locality or realism is not valid. All my bulleted authors above say, or tend to, give up on realism, especially Zeilinger himself.  

6 hours ago, Eise said:

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

We obviously have different interpretation of what some of there authorities have said.

As for realism, I say realism is dead, you say realism is dead, Zeilinger says realism is dead. Everybody agrees that realism is dead. What is your fixation about realism that you keep bringing it up again and again.  Can you state your point and move on?

6 hours ago, Eise said:

On 10/22/2022 at 12:17 AM, bangstrom said:

The mentioned equations say nothing about the timing of events between entangled particles when one is observed.

Exactly. Especially, they say nothing about a signal.

 The equations said nothing about a signal or the timing of a signal that is why I found them irrelevant.

6 hours ago, Eise said:

On 10/22/2022 at 12:17 AM, bangstrom said:

CHSH states that either a violation of locality or a violation of local realism would indicate that entangled particles do not have definite values before observed as is necessary for the EPR hypothesis to be correct. You may say that realism is violated and I ask, Why?

You are arguing in ill faith. Where CHSC clearly distinguish between the two assumptions, locality and realism, you are suddenly talking about 'locality' and 'local realism'. It was already explained to you ad nauseam that in CHSC 'local realism' means 'locality' and 'realism'. 

 What is in ill faith?

I understood that CHSC distinguished between locality and realism BEFORE you clowns tried to explain it again, and again, and again.

What is your objection about local realism? Local realism and realism were both violated by The Bell test so realism is violated simultaneously by different names.

And what is your obsession with the violation of realism. Everyone agrees that realism is dead, dead, dead but you keep bringing it up ad nauseam. What is the point you are trying to make?

5 hours ago, joigus said:

Realism is violated by QM in the most glaringly obvious way:

<snip>

IOW, QM violates realism in a way in which it implements an inherent, irreducible, totally from-the-ground-up indeterminism. Deeply-rooted indeterminism. Indeterministic to the bone and marrow.

Furthermore:

For entangled states with maximal entanglement entropy (Bell, GHZ, etc.) not even the individual quantum states are determined, let alone the underlying "reality" of eigenvalues.

Furthermore:

Identity of a particle doesn't mean anything --anything measurable, that is-- in QM.

These things appear to violate Einstein et al's. EPR article where the individual quantum states are determinate. Do you still claim that the violation of realism does not invalidate Einstein's view of realism?

23 hours ago, joigus said:

On 10/21/2022 at 1:52 AM, bangstrom said:

An exception is when newly entangled particles are created by some means such as spontaneous down conversion where their previous states are unknowable.

What do you mean spontaneous?

You mean parametric down conversion of photons? It's essentially the same case we've been discussing all the time.

Spontaneous parametric down conversion is something we have never discussed here because it is difficult enough to explain the results of quantum experiments without getting into the methods and SPDC is used in nearly all quantum experiments.

Down converted UV photons are not parametric until passed through a red filter so it is proper to to leave off the parametric part. SPDC involves passing a powerful UV laser light through a beta-barium borate crystal BBO to generate pairs of entangled photons. When a molecule of the crystal absorbs a UV photon it SPONTANEOUSLY emits two photons of lower energy. This happens much less than one time in a billion so it is a rare event called DOWN CONVERSION.

Two entangled photons of equal wavelength are necessary for experiments. PARAMETRIC means they have equal wavelengths. So a UV light passes through the crystal and rarely a pair of red entangled photons emerges. The red filter allows the photons to pass through without destroying the entanglement because it is not actually a measurement.

20 hours ago, Eise said:

Joigus mentioned it several times. And in Susskind's Quantum Mechanics; the theoretical minimum you find it on page 166. And here you find it on Wikipedia.

So refresh your memory:

The mentioned equations say nothing about the timing of events between entangled particles when one is observed.

I don't see the relevance.

21 hours ago, Eise said:

That simply is not what CHSH is about. It clearly distinguishes the two assumptions on which it is based: locality on one side, realism on the other side.

 

CHSH states that either a violation of locality or a violation of local realism would indicate that entangled particles do not have definite values before observed as is necessary for the EPR hypothesis to be correct. You may say that realism is violated and I ask, Why?

I say the preponderance of experimental evidence in favor of non-locality is evidence enough for dismissing local reality.

In either case, the EPR is no longer valid. Or would you disagree?

1 hour ago, MigL said:

Information, according to Relativity is constrained to stransfers equal to, or less than, the speed of light.
Are you saying Relativity is wrong ?

Relativity is correct but Einstein’s second postulate has an exception when it comes to the transactions among entangled particles needing to be no faster than light speed.
 

1 hour ago, MigL said:

3 hours ago, bangstrom said:

The three Nobel prize winners won their laurels for demonstrating the reality of non-locality

No, they did not demonstrate the 'reality of non-locality'.
They demonstrated the absence of local realism.

You can twist and bend that as much as you like, but they are NOT equivalent.

The absence of local realism was demonstrated by the violation of Bell’s inequalities that showed entangled particles do not have definite values prior to their observation.

The demonstration of a FTL signal between entangled particles is another observation that could violate local realism so either type of observation could do the job.

If one entangled particle is observed to be spin-up the other particle is instantly known to be spin down. This suggests some form of instant transfer of information from the observed particle to the unobserved particle if the the other particle is certain to be anti-correlated. But, perhaps not, there may be something to the entanglement that guaranteed the particles would be anti-coordinated when observed.

Zeilinger demonstrated with his quantum teleportation that the unobserved quantum identity of the second particle can also be determined by an even later entanglement nullifying the ability of the first entanglement to decide the anti-coordinated nature of the entanglement. This strongly suggests a non-local signaling among entangled particles.

2 hours ago, swansont said:

Quantum computing is not synonymous with entanglement. Where in discussion of the alleged entanlement “signaling” is it described as a single qubit? (not by you; you seem to only cite your own claim. I mean someone with credibility in the matter) 

Quantum computing involves entanglement for some things such as security keys.

I am having trouble getting this citation to work for details about qubits of information but you can look for:

Videos of Susskind Lectures #1 of #1 bing.com/videos

Or Leonard Sussikind Lecture 1|Quantum Entanglements, Part 1 (Stanford)

This will probably lead to a long series of videos. Look for the one with Sussikind standing in front of a hand drawn grid.

Skip the first 6 minutes.

2 hours ago, swansont said:

Then your explanation of identifying particle states in connection with entanglement is awkward. If particles that had determined states become entangled, you can’t tell which particle is which afterward, so you can’t tell if particles states have been reversed. 

 

If you know the before and after you can tell if the states have been reversed. If you go to Pisa Italy and find the Eiffel tower where the Leaning tower once stood, you know something has changed.

11 hours ago, swansont said:

Yes, you have frequently avoided answering the question. Where did you find this “official” description?

The non-local signal between two entangled particles is known as a ‘single qubit of information’. The word ‘qubit’ is common jargon used in discussing the non-local transfer of information found nearly everywhere the topic is discussed especially in quantum computing.

Susskind says physics is information and a ‘bit’ of information in physics is defined the answer to a binary question. It could be yes or no, 0 or 1, + or – etc.. A qubit of information is the answer to a binary question in QM. A classical bit of information is called a c-bit.

Qubit From 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.”

11 hours ago, swansont said:

 

12 hours ago, swansont said:

All entanglement is based on not knowing the states of the individual particles. “original state of a particle” makes no sense for an entangled particle. You can’t describe them in terms of individual states.

I never said one could know the individual states of entangled particles.

15 hours ago, Eise said:

Right. The only thing @bangstrom does is repeating points that he made already; evading questions; redefining words; suggesting his knowledge of QM is uptodate, where yours and Swansont's is not (on the brink of being insulting); cite text passages out of context or not relevant; and obfuscating with new formulations that have simply no content ('effect of correlation'). He is not seriously interested to learn something. He cannot confess he is wrong, either because he doesn't want to lose his face, or because he is ideologically attached to the idea of non-locality.

He is just trolling around.

I have no interest in relearning physics from the 1950's. The three Nobel prize winners won their laurels for demonstrating the reality of non-locality- aka "spooky action at a distance".

Einstein et al.'s EPR has been demonstrated as invalid by the the violation of Bell's inequality and reinforced by the quantum teleportation experiments by Zeilinger.

21 hours ago, Eise said:

Wrong as wrong can be. Susskind derives it in his book.

22 hours ago, bangstrom said:

What did Sussikind have to say and are you dismissing the many experiments demonstrating that quantum entanglement is non-local, 'instant'?

21 hours ago, Eise said:

She says that only 2 assumptions flow into the CHSH inequality locality and realism. And she says literally:

Quote

The way that most scientists have interpreted this, is that we have to give up on the idea of realism

I have repeatedly stated that we have to give up on the idea of realism. Where do you find a difference in our views?

21 hours ago, Eise said:

22 hours ago, bangstrom said:

Zeilinger was able to take advantage of entanglement swapping with his quantum teleportation where he could instantly transfer the quantum identity of one entangled particle to another entangled particle far away.

Nope. Not instantly. They even had to ensure that the entangled photons were delayed, so that the conventional signal arrive at Bob first. So quantum teleportation is slower than FTL. 

I thought this misconception was cleared up long ago. Alice and Bob are not entangled particles so their communications are always classical with space-like time between them. Their communication is always slower than light speed.

Quantum signaling is between entangled particles and that is the only part that is non-local, 'instant'. I hope that is clear.

Forget about Alice and Bob.

12 hours ago, swansont said:

No, the best you can say is if there is a signal, it’s superluminal. But you haven’t identified the signal.

I have frequently given the official description of the signal. It is defined as a single qubit of quantum information.

12 hours ago, swansont said:

Teleportation destroys the knowledge of the state of the source particle; it’s not a copy, since that would violate the “no-cloning” theorem

The knowledge of the original state of the particles is destroyed. If the original state of a particle to the left was spin-down and the particle to the right was spin-up, then when entanglement is gained and then lost, the spin states can be reversed. The particle to the left can be spin-up while the particle to the right is spin-down. A naive view is that the particles have swapped places but the particles have remained in place and only swapped quantum identities.

An exception is when newly entangled particles are created by some means such as spontaneous down conversion where their previous states are unknowable.

On 10/16/2022 at 9:06 AM, swansont said:

Or show where the formula indicates a signal between the particles. 

Eise claims to have the formula but I don't think there is one. The evidence for a non-local signal is observed in experiments but I don't know of any formula.

6 hours ago, swansont said:

No, it’s that the particles are in undetermined states. There is no “swap” 

Since there is a correlation of states, all of the information about the states is revealed once you make a single measurement.

If the observed quantum particle identities before entanglement are reversed after entanglement, they have "swapped" locations. Zeilinger's quantum teleportation is another example of entanglement swapping.

Just now, bangstrom said:

 

3 hours ago, joigus said:

Anyway, correlation is not causation.

Correlation is an effect and not a cause.

7 hours ago, Eise said:

Wrong as wrong can be. Susskind derives it in his book.

What has Susskind derived and is the speed of a signal via entanglement what he is discussing and not the speed of the after analysis?

7 hours ago, Eise said:

She says that only 2 assumptions flow into the CHSH inequality locality and realism. And she says literally:

Quote

The way that most scientists have interpreted this, is that we have to give up on the idea of realism

I have said several times that we have to give up on the idea of realism. Where do you see a difference in our claims?

7 hours ago, Eise said:

Nope. Not instantly. They even had to ensure that the entangled photons were delayed, so that the conventional signal arrive at Bob first. So quantum teleportation is slower than FTL. 

Quantum teleportation is instant from particle to particle. The signal is classical from Alice to Bob and slower than FTL.

I thought this was clear long ago. Totally forget about 'what's their names.' The non-local, instant signal is entangled particle to entangled particle. Quantum entanglement can not be used for human FTL communication and that is a whole different topic and connection.

4 hours ago, joigus said:

You're confusing correlation with causation. That's not what I'm saying. The experimenter's minds are determined by a common cause, either in the past --exactly as in the singlet state-- or not. Only state of affairs is more complicate in the case of the singlet.

Confusing of correlation with causation can be very, very misleading. Sometimes, not even causal connection in the past can be significantly attributed.

For causation to be attributed, you must have a theory for the common cause.

4 hours ago, joigus said:

You're confusing correlation with causation. That's not what I'm saying. The experimenter's minds are determined by a common cause, either in the past --exactly as in the singlet state-- or not. Only state of affairs is more complicate in the case of the singlet.

Confusing of correlation with causation can be very, very misleading. Sometimes, not even causal connection in the past can be significantly attributed.

For causation to be attributed, you must have a theory for the common cause.

Correlation is an effect, not a cause. What do you think is the cause of correlation?

On 10/16/2022 at 8:15 AM, joigus said:

Because the truth of the theorem was already encapsulated in their respective minds long before they performed the measurement.

You appear to be saying that what the experimenters think determines the outcome of the experiment. The sort of experiment mentioned in the OP was the experiment that won the Nobel for Aspect and Clauser. Clauser was certain that the experiment would support local realism and locality as found Einstein's EPR paper but it failed to do so.

On 10/16/2022 at 6:12 AM, Eise said:

Which of "not an article about QM" you did not understand?

In the hope I correctly understand Swansont's Ansatz, he is doing the following. He gives you the formula which rolls out of the math of QM. I hope you recognise it. Joigus also mentioned it (I think even a few times). The importance of the formula in this context is that it does not contain a dependency of the distance between the measurements, i.e. it is valid even if the measurements are space-like separated. So your task is to show the formula wrong.

There is nothing wrong with the formula except that it does not apply to the issue of the speed of a signal. The formula is classical like a calculation one could use for flipping coins and it says nothing about the timing of events.

John Bell supplied the QM version of the same equation which allowed for more possibilities than permitted by the classical version.

The timing of a signal when entanglement is lost is derived from actual experiments. It is not mathematically derived so asking for a mathematical derivation makes no sense.

On 10/16/2022 at 6:12 AM, Eise said:

On 10/16/2022 at 4:23 AM, bangstrom said:

I find the views expressed here so far about quantum entanglement to be outdated and quite contrary to the mainstream consensus (not that that makes them wrong).

The IBM lady you have called as witness, disagrees with you. The video is less than 50 years old...

 She said there is no such thing as FTL communication but the transaction that maintains entangled particles as anti-coordinated on both ends is a single qubit signal which has been declared as having too little information to qualify as a 'communication'. Also, because the signal is non-local action at a distance with no movement within the signal, it does not fit the definition of a communication.
 

On 10/16/2022 at 6:12 AM, Eise said:

Your citation contains no description of the question 'locality or realism'. I think it also contains nothing Swansont would disagree with. So this article might be a correct description of entanglement, but it is not relevant.

I think Swansont said something about how entangled particles are anti-correlated because their quantum properties remain unchanged from the start but the violation of the Bell test and actual experiments indicate they are not. If entangled particles can instantly ‘swap identities’ while remaining anti-correlated, this requires some form of non-local, instant transfer of information.

This is the part of the citation that specifically refers to locality and local realism.

“Surprisingly, it is also viable to generate quantum entanglement between quantum particles or systems that have not directly interacted with one another. It can be done through entanglement swapping.”

Entanglement swapping of quantum properties is entirely unknown at the macro level. We know that the Eiffel tower is in Paris and the Leaning Tower is in Pisa. Both towers have a specific ‘location’ but Entangled particles have no ‘location’. Their locations, like their other properties, are indefinite until observed. Because they have no locality, locality is violated and because entangled particles can instantly swap identities, local realism is violated. The loss of entanglement is instant and non-local.

Zeilinger was able to take advantage of entanglement swapping with his quantum teleportation where he could instantly transfer the quantum identity of one entangled particle to another entangled particle far away. Entanglement swapping is a violation of local reality, and since it can happen instantly across any distance makes it non-local so locality is also violated.

On 10/16/2022 at 6:12 AM, Eise said:

13 hours ago, hoola said:

if alice determines an up and that delivers a down measurement for bob, what if they determine their respective particles at the same instant in time, should that somehow be made to happen, and would that matter to the outcome?

Experiments such as the one you are asking have been done many, many times and with greater accuracy over the years. The observations are that A and B can't be far enough apart and the measurements can't instant enough to change the expected outcome. By comparing the shortest times between measurements and the distance between A and B  it is possible to find a lower limit for the time of the interaction compared with c.

https://newatlas.com/quantum-entanglement-speed-10000-faster-light/26587/

https://www.scientificamerican.com/article/china-shatters-ldquo-spooky-action-at-a-distance-rdquo-record-preps-for-quantum-internet/

https://www.newscientist.com/article/2134843-chinese-satellite-beats-distance-record-for-quantum-entanglement/

"Quantum entanglement, one of the odder aspects of quantum theory, links the properties of particles even when they are separated by large distances. When a property of one of a pair of entangled particles is measured, the other "immediately" settles down into a state compatible with that measurement. So how fast is "immediately"? According to research by Prof. Juan Yin and colleagues at the University of Science and Technology of China in Shanghai, the lower limit to the speed associated with entanglement dynamics – or "spooky action at a distance" – is at least 10,000 times faster than light."