crowded quantum information

[joigus]

1 hour ago, bangstrom said:

The violation of the Bell test indicates that the quantum properties of the entangled particles are not established from the start so the first observation is random (Alice's observation in this case) and the second observation is instantly decided by the first. Even if it is beyond the range of a light speed signal.

The properties of the entangled particles are established from the start. When a neutral pion decays into two photons, all the correlations are there from the start.

Both measurements are random. But any observer that has access to both results, once information from both Alice and Bob is gathered and "centralised" --and therefore the criterion for FTL or not FTL will long have been outdated-- will discover eventually that the results were anti-correlated, if they happened to measure the same projection of spin. And they will be totally non-correlated, if they happened to measure different projections of spin.

The tenses in "will" and "were" are essential here.

At the moment they measure spin, either Alice or Bob, they write down the result, but they have no way to know whether:

1) The other one measured the same projection of spin, and their result is anti-correlated with theirs.

or,

2) The other one measured another projection of spin, and their result is totally non-correlated with theirs.

I told you, it's like a house of cards. If you drop randomness but keep quantum superpositions, sending FTL signals would become possible. That doesn't happen.

If you drop quantum superpositions and non-commutativity, it becomes like a pair of gloves dice that are totally correlated (or anticorrelated, as the case might be) for every observable.

It's random, totally, unmistakably. And it's superpositions (no internal reality.)

It's impossible to explain this to you with firecrackers, boots, dice, or little leprechauns that take decisions. Firecrackers don't have internal non-commuting variables. There is a fathomless void, and impossibility, an insurmountable logical obstruction here in the space of classical analogies.

There are no classical analogies.

Local, totally. But random, not because,

1 hour ago, bangstrom said:

[...] because one fuse might catch before the other, manufacturing differences, lengths etc. etc..

but because:

No. No internal mechanism, no manufacturing differences, no internal switches. Nothing. Niente. Nada. Nichts. Zilch. Quantum mechanics! Quantum mechanics! Quantum mechanics!

 

3 hours ago, TheVat said:

Am going to try and read this thread this weekend, not only to better understand the scientific attitudes towards realism, but also how someone broke Joigus.  JK.  

Oh, no matter, you can say that they broke me. I was playing this ping-pong match Nadal style, until I finally went all Djokovic on Bangstrom.

3 hours ago, TheVat said:

Years ago, I had this notion that entanglement was analogous too two distant astronauts tethered together.  When the tether breaks in the middle, there is no FTL signal, but their state changes instantly to "untethered." Nothing spooky.  Just a change such that, if we measure either astronaut for tetheredness, we will find them unmoored.  Yeah.  That was when I realized it was a mistake to map RW situations onto QM.  

It's not a totally bad analogy. But all our classical analogies are doomed in the end, because classical tethers cannot reproduce non-commutativity: Say, eg, in the case of the astronauts, (nationality)x(handedness)-(handedness)x(nationality) = i x (gender)

What the hell does that mean in terms of tethers, coins or dice?

Systems that behave this "crazy" deserve the name of "quantum." The intermediate tether holds the anti-correlation, but in such a way that, while it's evolving, following the Schrödinger equation, it cannot be said --without falling into inconsistencies-- that the astronauts are this or not this, that or not that. They are in a quantum superposition of all the "this" and "not this" possible questions. Being American or not, lefty or not, woman or not, equally likely.

When you put two astronauts inside respective space pods, you want to believe they either are American or not American, lefty or not lefty, and a woman or not a woman. You want to believe, eg, the American is, say, left-handed, and a woman. She must have been!! She was all that from the get go!! Then the other one is not American, right-handed, and a man. You want to believe that, naturally! Why, they are real astronauts, right? If the American is a woman, she must have been a woman all along. If she's right handed, she must have been RH all along, etc. That's what doesn't work with quantum systems. The system "selects" the pairing of results --corresponding to one property-- only after you perform your measurement, and not before.

And I say "pairings of results" knowing full well what I mean. According to QM, if I want to know if the astronaut is a woman, I must give up knowing whether she's LH or RH, or her nationality. The reason is they are incompatible properties.

If you "measure" the gender, one space pod has a woman in it, and the other has a man.

If you measure the nationality, one space pod has an American, the other not.

What if you "measure" the handedness in one and the gender in another? Then anything's possible. You sometimes get a lefty here and a woman there, a right-handed here and a woman there, etc. All combinations equally likely. 

It is an intimate connection between the astronauts, much more intimate than you could get with any classical bipartite system. It's as if they both were just one thing, and you could only look at each of the "parts" through one filter: nationality, or handedness, or gender. You must decide which one.

I don't know how to package that into a single analogy. The best I can do is: Try to picture a reason why, if you want to know my gender, you absolutely cannot say anything about my handedness, or my nationality. In fact, if I'm a man, I'm absolutely neither right-handed, nor left-handed, neither American, nor not American.

This is as weird as can be, but not because of non-locality. It's because of non-realism. Because gloves, and dice, and coins are real --whatever that means--, they hold all their meaningful properties at once --yeah, that's what it means!!--, they can't illustrate anything deep about QM one hundred per cent.

19 minutes ago, joigus said:

or little leprechauns that take decisions.

Little leprechauns that take decisions would actually be possible to accomodate to superdeterminism.  

Edited October 14, 2022 by joigus
minor change

[swansont]

2 hours ago, bangstrom said:

There seems to a major misunderstanding here and it has nothing to do with SR.

I can give a simple example and, if it makes sense, we can go from there.

Suppose you take two firecrackers and twist the fuses together so when lit they both go off at the same time. You light the fuses and both firecrackers go off so close to the same time that there is no way of knowing which went first. It is next to impossible to get two firecrackers to fire simultaneously because one fuse might catch before the other, manufacturing differences, lengths etc. etc..

If they are co-located, everyone agrees that the events are simultaneous. This is a poor example to use, since the issue at hand involves measurements that are not co-located.

Firecrackers that go off simultaneously according to an observer in one frame will not be seen as going off simultaneously in other frames if the firecrackers are separated. 

If they are separated, “both firecrackers go off [at] the same time” is not a blanket statement you can make. It is always frame-dependent.

[bangstrom]

17 hours ago, swansont said:

If you aren’t ignoring it, please show me where QM requires the signal you insist is present. 

Not your personal unsupported opinion, mind you.

 

"In the simplest terms, quantum entanglement means that aspects of one particle of an entangled pair depend on aspects of the other particle, no matter how far apart they are or what lies between them. These particles could be, for example, electrons or photons, and an aspect could be the state it is in, such as whether it is “spinning” in one direction or another.

The strange part of quantum entanglement is that when you measure something about one particle in an entangled pair, you immediately know something about the other particle, even if they are millions of light years apart. This odd connection between the two particles is instantaneous, seemingly breaking a fundamental law of the universe. Albert Einstein famously called the phenomenon “spooky action at a distance.”

QM found it necessary to incorporate non-local entanglement after the theoretical experimental work of Bell and Aspect.

Entanglement demonstrates the presence of some kind of 'signaling', for the lack of a better word, between remote particles where an observation of one particle non-locally affects it's entangled partner.

https://www.bing.com/search?q=In+the+simplest+terms%2C+quantum+entanglement+means+that+aspects+of+one+particle+of+an+entangled+pair+depend+on+aspects+of+the+other+particle%2C+no+matter+how+far+apart+they+are+or+what+lies+between+them.+These+particles+could+be%2C+for+example%2C+electrons+or+photons%2C+and+an+aspect+could+be+the+state+it+is+in%2C+such+as+whether+it+is+“spinning”+in+one+direction+or+another.&FORM=AFSCVO&PC=AFSC

 

17 hours ago, swansont said:

 You really have no clue about relativity and simultaneity, too.

The part I don't understand is what bit of information do we gain from relativity that is useful in interpreting the recently mentioned Alice and Bob experiment with entangled particles?

 

 

 

 

17 hours ago, swansont said:

 

 

10 hours ago, swansont said:

If they are co-located, everyone agrees that the events are simultaneous. This is a poor example to use, since the issue at hand involves measurements that are not co-located.

I gave two examples, one with co-located firecrackers, and an Alice and Bob scenario. Alice and Bob examples are always in the same reference frame but as widely separated one would care to make them. In my Alice and Bob scenario, I said they were one light second apart. Should they have been farther apart?

10 hours ago, swansont said:

Firecrackers that go off simultaneously according to an observer in one frame will not be seen as going off simultaneously in other frames if the firecrackers are separated. 

Did you figure that out by yourself?

10 hours ago, swansont said:

If they are separated, “both firecrackers go off [at] the same time” is not a blanket statement you can make. It is always frame-dependent.

I said the firecrackers were together, twisted fuses and all. If they were separated the observations would be different. Who’d a thunk it.

16 hours ago, Eise said:

21 hours ago, bangstrom said:

That is the 'realism' we have to give up.

But then, we see how you bend what is said, even in your video. At 7:55 she says that the only two assumptions that went into the CHSH inequality are locality and realism. See the screenshot I made from the video.

So it is locality or realism (or both) that we must give up. And to repeat: later on she says "The way that most scientists have interpreted this, is that we have to give up on the idea of realism".

I underlined the last part and how is that different from what I said in my quote above?

[Eise]

2 hours ago, bangstrom said:

Entanglement demonstrates the presence of some kind of 'signaling', for the lack of a better word, between remote particles where an observation of one particle non-locally affects it's entangled partner.

And another foot shot. From the same article:

Quote

Importantly, there is also no conflict with special relativity, which forbids faster-than-light communication. The fact that measurements over vast distances are correlated does not imply that information is transmitted between the particles. 

Italics and bold by me.

2 hours ago, bangstrom said:

I underlined the last part and how is that different from what I said in my quote above?

You redefined 'realism', so that it contains 'locality'. But your IBM speaker clearly distinguishes in a very technical way between the two, namely as the only two assumptions of the CHSH inequality.

You've made clear for all of us:

• You cannot understand the argumentative arc of texts
• And related, you cite pieces of texts that seem to support you viewpoint, but in fact the text as a whole does not
• You are not able to refer to a modern article (less than 50 years old, if you know what I mean) of a respectable physicist that defends that of the two, locality and realism (in their technical sense, not in your unjustified interpretation of it), we have to give up on locality
• You do not understand how we use special relativity to argue that there is no direction in the correlation of Alice's and Bob's measurements
• You do not even understand special relativity
• And last but not least, you simply do not understand quantum mechanics.

I think we should close the thread. Because of Joigus' mental health 😉, and my ability to express my free will (didn't I say I am out?) 😟, and because of this:

And I found this elaborate extension of it:

 

Edited October 15, 2022 by Eise

[joigus]

2 hours ago, Eise said:

And another foot shot. From the same article:

Italics and bold by me.

You redefined 'realism', so that it contains 'locality'. But your IBM speaker clearly distinguishes in a very technical way between the two, namely as the only two assumptions of the CHSH inequality.

You've made clear for all of us:

• You cannot understand the argumentative arc of texts
• And related, you cite pieces of texts that seem to support you viewpoint, but in fact the text as a whole does not
• You are not able to refer to a modern article (less than 50 years old, if you know what I mean) of a respectable physicist that defends that of the two, locality and realism (in their technical sense, not in your unjustified interpretation of it), we have to give up on locality
• You do not understand how we use special relativity to argue that there is no direction in the correlation of Alice's and Bob's measurements
• You do not even understand special relativity
• And last but not least, you simply do not understand quantum mechanics.

I think we should close the thread. Because of Joigus' mental health 😉, and my ability to express my free will (didn't I say I am out?) 😟, and because of this:

And I found this elaborate extension of it:

 

LOL.

I'm passionate about arguing, and I can't hide the fact that I'm loving this particular debate. But in the end it's about learning, not about winning. I've tested your patience in the past, haven't I? I learnt a very important observation back then from our debate on free will. Namely: The fact that a property is emergent doesn't make it any-the-less factual, any-the-less consequential. It was so important to learn that I may have missed other, more subtle points you were making. But I'm thankful for having learnt something from that debate.

If the landscape of ideas eventually gets cleared up in this debate, then perhaps we will be able to tackle the "crowding of information" that @hoola was talking about, with interesting advances like, eg,

https://phys.org/news/2021-08-critical-advance-quantum.html

Which go right to the heart of the matter as per OP question. The crowding of millions of qbits.

Or perhaps we will be able to discuss what happens to the wave function when measurements are performed, or whether the state vector is a figment of our imagination or not. Or whether we should consider the quantum phase as a placeholder for beables. Or...

 

[swansont]

11 hours ago, bangstrom said:

I said the firecrackers were together, twisted fuses and all. If they were separated the observations would be different. Who’d a thunk it.

Yes, and I questioned the relevance of the example.

Perhaps you could actually answer the questions put to you. Or perhaps the reason you don’t is that you can’t.

11 hours ago, bangstrom said:

 

"In the simplest terms, quantum entanglement means that aspects of one particle of an entangled pair depend on aspects of the other particle, no matter how far apart they are or what lies between them. These particles could be, for example, electrons or photons, and an aspect could be the state it is in, such as whether it is “spinning” in one direction or another.

The strange part of quantum entanglement is that when you measure something about one particle in an entangled pair, you immediately know something about the other particle, even if they are millions of light years apart. This odd connection between the two particles is instantaneous, seemingly breaking a fundamental law of the universe. Albert Einstein famously called the phenomenon “spooky action at a distance.”

QM found it necessary to incorporate non-local entanglement after the theoretical experimental work of Bell and Aspect.

Entanglement demonstrates the presence of some kind of 'signaling', for the lack of a better word, between remote particles where an observation of one particle non-locally affects it's entangled partner.

You should provide a citation when you post a quote 

And I asked for QM, not an article about QM (which, as Eise points out, says that there is no signal)

The QM says that if I have 1/sqrt2 |12> - 1/sqrt2 |21> and I make a measurement, I will get either |12> or |21>. IOW I will know the states of both. 

There’s nothing about a signal between the particles. It’s simply not part of the theory.

[bangstrom]

18 hours ago, swansont said:

You should provide a citation when you post a quote 

And I asked for QM, not an article about QM (which, as Eise points out, says that there is no signal)

I did provide a citation and it was one of those really long ones.

You asked for a QM citation and not just my personal opinion and you and you got it.

I have explained several times that signal via entanglement is a one qubit of information and that is not officially sufficient an amount of information to be considered a 'communication'.  It may be faster than light but it is not a 'communication' faster than light. I find that a bit contrived but that is the way it is explained.

18 hours ago, swansont said:

It’s simply not part of the theory.

It's not part of which theory? QM, EPR, classical?

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). I am inclined to ask, if entanglement is not non-local and nothing unusual or anything that can not be described as classical or a violation of the EPR effect, then why did the Big Three ACZ win the Nobel for discovering something so ordinary?

I am obviously either quite wrong or haven’t made myself clear about anything. My views about about entanglement can be found in this simple article.

https://byjus.com/physics/quantum-entanglement/  (this is a citation)

Here are the high-lights.

“Quantum entanglement is one of the most bizarre phenomena occurring in the quantum realm. When multiple particles are linked in a particular way, even if they are far away from each other, their states continue to be connected. In simple terms, they share an identical quantum state.”

“Quantum entanglement is a quantum phenomenon whereby a group of particles is produced so that their quantum states are unclear until calculated as a whole. The act of calculating one decides the result of calculating the other even if they are far from each other. In other words, each particle’s quantum state cannot be sketched independently of the state of other particles (despite the spatial differences).”

“The subject of quantum entanglement is at the centre of the fundamental difference between quantum and classical mechanics. Entanglement is a unique quantum phenomenon that is completely absent in classical physics.”

“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. Two identical particles from different sources could be entangled if their wave function just spatially overlapped (at least partly).”

“The word “entanglement” was first used by physicist Erwin Schrödinger (one of the pioneers of quantum mechanics). He explained quantum entanglement as one of the fundamental features of quantum mechanics. He said that its presence is an absolute deconstruction of classical mechanics or physical logic.”

Edited October 16, 2022 by bangstrom
Citation didn't work. Changed citation

[Eise]

2 hours ago, bangstrom said:

You asked for a QM citation and not just my personal opinion and you and you got it.

I think Swansont asked for a QM derivation, not for citations:

20 hours ago, swansont said:

And I asked for QM, not an article about QM

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.

2 hours ago, bangstrom said:

It's not part of which theory? QM, EPR, classical?

QM. Just QM.

2 hours ago, bangstrom said:

My views about about entanglement can be found in this simple article.

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.

2 hours ago, 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...

2 hours ago, bangstrom said:

I am inclined to ask, if entanglement is not non-local and nothing unusual or anything that can not be described as classical or a violation of the EPR effect, then why did the Big Three ACZ win the Nobel for discovering something so ordinary?

Because, from a classical view, the results are outrageous. Two of the fundamental assumptions of classical physics are challenged, locality and realism (in the technical sense of those words, not of your vague interpretations of them, see CHSH). There obviously were physicists that trusted QM so much, that they did not find it necessary to do such experiments, e.g. Feynman. He was not interested in Clauser's experiment. And Zeilinger's experiments also lead the way to applications of entanglement: quantum cryptography, quantum teleportation and quantum computing. You did read the articles on the Nobel prize website, didn't you? But of course you did not understand them.

2 hours ago, bangstrom said:

“The word “entanglement” was first used by physicist Erwin Schrödinger (one of the pioneers of quantum mechanics). He explained quantum entanglement as one of the fundamental features of quantum mechanics. He said that its presence is an absolute deconstruction of classical mechanics or physical logic.”

Hm. Reminds me of a posting here...

Edited October 16, 2022 by Eise

[joigus]

2 hours ago, 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). I am inclined to ask, if entanglement is not non-local and nothing unusual or anything that can not be described as classical or a violation of the EPR effect, then why did the Big Three ACZ win the Nobel for discovering something so ordinary?

EPR is not an effect, nor is it a "theory" as you say further below this quoted piece of text.

EPR is a theoretical argument presented as a contingency:

• If this (what I propose here) is true, then that (what you've been saying) must be false.
• If what you've been saying is true (in the face of this example), then something we know for sure (relativistic causality) would have to be false.

It's a bit involved, granted. But no "effect" is proposed, and no "theory." And it is a very crude argument in its original form, although it's very astute.

The EPR argument, in its original form, is quite flawed. I've tried to explain why somewhere else:

https://www.scienceforums.net/topic/127991-an-analogy-for-superposition/#comment-1219399

22 hours ago, joigus said:

But he (and Rosen, and Podolski) missed a couple of tricks.

1) You cannot prepare a bipartite quantum state in which the momentum is zero in the CoM system with total accuracy. So momentum is actually always indefinite.

2) The state is actually entangled: (momentum p)_{particle 1}(position x)_{particle 2}-(momentum -p)_{particle 1}(position -x)_{particle 2}.

Here, David Bohm enters the story. He took the whole discussion to the case of spin. Why? Because angular momentum is exactly conserved, but for angular momentum (spin is a particular case) you can actually prepare states that are totally indefinite in each variable, while completely definite for the sum of both. Then you can do the correlation analysis very cleanly, and reasonably clearly.

Then comes John Bell, and for some unfathomable reason --IMO-- rescues a word from Einstein's old toolbox that had better been left out, because --again, IMO-- plays no actual role in the argument, except indirectly. Namely: "locality."

In fact, if you go over Bell's papers on the subject, and its antecessors: V. Neumann, Gleason, Jauch and Piron, etc., and its sequel: Clauser, Greenberger, Horne, Zeilinger; the position of the particle plays no role in the theorems. It's not even mentioned in the axioms. It's only there because these great physicists mention it over and over. Why? Because Einstein mentioned it in his original argument. And they have deep respect for Einstein. And they don't want to be wrong.

They all knew in their heart of hearts they were doing a theorem about realism, but didn't want to drop this word "locality," --IMO-- only just in case they missed something essential. But all those theorems about "local realism" were actually theorems about "realism." If I disprove local realism, it's just as good to disprove realism. If there isn't any realism, there certainly won't be any local realism.

Nobody said "nothing unusual," and certainly nobody said "nothing non-classical." It's completely non-classical. It's quantum mechanics!

ACZ and others performed experiments which bring out the flavour of quantum mechanics at its most strange and counter-intuitive: This fundamental non-reality can be transported at a distance. For one thing, they proved quantum mechanics to be right. For another thing, they managed to keep quantum coherence for very long distances. The last one in particular is a monumental technological achievement.

This could be very useful for quantum computing. I'm thinking, eg, that you could delay the decision of defining a qubit until some ancillary calculation is completed. You could decide to set your qubit to a totally random couple of qbit states. It gives you handlers for your qubit logical gates (the AND, the NOT, the OR, the CNOT...). When you transport qubits instead of bits, there's a phenomenally richer set of possibilities. You would have to ask an expert in quantum computing to learn more. But you could do many things with those gates that would be impossible with classical gates.

[swansont]

2 hours ago, Eise said:

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.

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

[bangstrom]

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:

Edited October 20, 2022 by bangstrom
Added word "entanglement swapping."

[Eise]

51 minutes ago, bangstrom said:

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

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

1 hour ago, bangstrom said:

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.

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

 

1 hour 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. 

 

Troll.

[swansont]

1 hour ago, bangstrom said:

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.

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.

[joigus]

Dear @bangstrom. I think it's very much possible that at the bottom of your misunderstanding of this question is your confusion of causation with correlation. I've just commented on a related topic:

The theme "correlation is not causation" could be where you're having difficulties. I do suggest you to do a look-up for that theme on SFN. It's come up before in many different contexts.

I've seen statistics in the past going something like "people who take the bus are more prone to getting cancer."

A hurried interpretation of this could be true, not because taking the bus is giving you cancer, but because, if you're more likely to take the bus, you're also more likely to be exposed to carcinogens, on the grounds that your lifestyle is more likely to be whithin that particular statistical cohort.ç

Anyway, correlation is not causation.

[bangstrom]

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.

[joigus]

45 minutes ago, bangstrom said:

Correlation is an effect and not a cause.

Correlation is an effect, or a coincidence. Depends. Most of the times it's an effect of something happening before, or even independently of time. Yeah, sure. It's an effect. An effect of what?

Correlation (positive) between A and B. Possibilities:

1) A causes B

2) B causes A

3) Both, A and B, are caused by the same: C

4) A is caused by B plus other factors (not perfect correlation: B makes A more likely)

5) B is caused by A plus other factors (not perfect correlation: A makes B more likely)

6) Both A and B are caused by common cause plus other factors (both are more likely together because antecedent cause C makes both more likely)

7) Coincidence... If you can expand the sample space you can in principle rule this out.

I think you're confused beyond recovery here. Also, you constantly cherry-pick what you want to answer. On top of that, you don't distinguish anything relevant here with any care.

"Correlation is an effect." Yeah, sure. And a thing is a thing. And what's more, an effect is a something. And something is some thing.

Thank you for your illuminating arguments --I'm being sarcastic.

[swansont]

1 hour ago, bangstrom said:

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.

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

 

1 hour ago, bangstrom said:

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.

Since the states are undetermined, this is moot

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

 

[bangstrom]

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.

Edited October 21, 2022 by bangstrom
Added qu to bit.

[Eise]

14 hours ago, bangstrom said:

Eise claims to have the formula but I don't think there is one.

WHAT? Swansont showed it:

On 10/15/2022 at 5:23 PM, swansont said:

The QM says that if I have 1/sqrt2 |12> - 1/sqrt2 |21> and I make a measurement, I will get either |12> or |21>. IOW I will know the states of both. 

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:

On 10/16/2022 at 4:06 PM, swansont said:

On 10/16/2022 at 1:12 PM, Eise said:

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.

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

It is called the singlet state, and QM shows it can be created.

14 hours ago, bangstrom said:

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?

In that you shifted the meaning away from how it is used in the CHSH inequality. For you, realism includes locality. For CHSH it doesn't.

Here you are redefining it:

On 10/14/2022 at 11:35 AM, bangstrom said:

When entanglement is lost, it is lost instantly across both ends of the wave function and experiments have demonstrated that the changes to one particle are simultaneous with changes other particle. This is why the interaction is considered to be non-local and FTL. Since no physical connection is involved, that is what Einstein called “Spukhafte Fernwirkung” and he thought, That can't be right.

That is the 'realism' we have to give up.

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.

 

[joigus]

1 hour ago, bangstrom said:

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

If that's your argument, it's as good as saying that the description of an angel consists in that it's defined as a single being of pure grace. This is a non-argument. You have no experimental basis for your FTL signal, nor theoretical description of it.

1 hour ago, bangstrom said:

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.

(my emphasis in bold)

Wrong. The spatial part of the state propagating to the left is a quantum superposition (up)₁(down)₂-(down)₁(up)₂, and the spatial part of the state propagating to the right is too.

1 hour ago, 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.

Eise is reminding you that none of your points are new. We've visited them before. But every time you make a new comment, I find more and more ways in which it's obvious you totally misunderstand both the facts, and the formalism of quantum mechanics. There is no such a thing as "the identity of a particle" in quantum mechanics. The state is undetermined in the particle indices. There is no such thing as "spontaneous down conversion." Etc.

And you haven't "described" the signal yet. You've just given it a fancy name.

Edited October 21, 2022 by joigus
minor correction

[Eise]

30 minutes ago, joigus said:

Eise is reminding you that none of your points are new. We've visited them before. But every time you make a new comment, I find more and more ways in which it's obvious you totally misunderstand both the facts, and the formalism of quantum mechanics.

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.

Edited October 21, 2022 by Eise

[swansont]

4 hours ago, bangstrom said:

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

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

 

4 hours ago, bangstrom said:

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.

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.

[joigus]

9 hours ago, Eise said:

[...] cite text passages out of context or not relevant; and obfuscating with new formulations that have simply no content ('effect of correlation').

(My emphasis in bold)

Yes. Another thing that bothers me is that sometimes it's a transaction or handshake --TIQM--; while other times it's the collapse of the quantum state --Copenhagen. One would think it's one or the other.

But, as I said before, let them clean their own house.

[bangstrom]

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.

[swansont]

1 hour ago, bangstrom said:

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.”

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) 

 

1 hour ago, bangstrom said:

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

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.