bangstrom

To simplify this discussion I would be satisfied if everyone ignores all of my questions and just answers those on Eise's list. When entanglement is lost, it is not renewed. Multiple particle entanglements have been observed. As I recall, nearly one hundred particles have been observed to be part of a group entanglement and the count is rising.

My understanding is that the topic here is about quantum entanglement and about the use of entanglement for superluminal communication at the macro level. That is Alice and Bob. I thought the we had put to rest with certainty that superluminal communication at the macro level (Alice and Bob) is absolutely impossible under any circumstances. I hope we can also agree that impossibility of non-local communication at the macro level is irrelevant to what may be happening at quantum level. Your two recent references, are about macro communication of the Alice and Bob type. I have explained in detail why the classical view is irrelevant to what is happening at the quantum level. More references about the dead issue of classical communication being local is just another irrelevant ‘ping’ waiting for a ‘pong’. You did have an interesting but lengthy article that included a discussion of the EPR/B experiment that was about quantum entanglement at the quantum level and the authors’ conclusion was that the events were local. My first impression was that they were ignoring the wave-like entanglement itself which is where non-locality resides. I intend to review the article when I have the time but I don’t intend to comment until I have reviewed the article in detail and considered the validity of my first impression. Are you saying, QUANTUM MECHANICS IS LOCAL ? From my reading, QM allows for non-locality and this appears to be the long term, widely held consensus. I know there are contrary opinions about all physics being local, including QM, from dubious sources like the Superdeterministic school but can you support your views with more than just personal opinion or your impressions of what Aspect or Bell had to say. I know what they said.

I have never stated that entangled particles have an observable state before they are observed. I have repeatedly stated that the quantum state of entangled particles is indeterminate prior to the first observation and I have never stated that they communicate. Apparently you have imagined a model different from my own. You only presented one side of the issue. Entanglement is necessarily two or more sided. I explained how your analogy works on both sides. Your complaint I changed your analogy is petty.

The coin flip analogy is a good one. But if one person flips a coin in Hong Kong and another flips a coin in London and their random flips are always anti-coordinated this demonstrates a non-local connection of a sort not permitted by classical physics. QM does not require a direct physical connection for one particle to be able to effect the condition of a remote particle if the two particles are entangled. QM permits non-locality. Classical physics does not. That is a major distinction between the two. That’s right, hidden variables have been eliminated as an alternate explanation for non-local interactions. Classical mechanics does not permit non-local interactions without a direct physical contact. “Spooky action at a distance” is not possible according to classical physics. In QM non-local interactions are possible. Here via wiki are quotes from Bell. https://en.wikipedia.org/wiki/Bell's_theorem "In the words of physicist John Stewart Bell, for whom this family of results is named, "If [a hidden-variable theory] is local it will not agree with quantum mechanics, and if it agrees with quantum mechanics it will not be local."[1] Also, from another source. "Bell's theorem is a "no-go theorem" that draws an important distinction between quantum mechanics (QM) and the world as described by classical mechanics. It proves that quantum physics is incompatible with certain types of local hidden-variable theories. This theorem is named after John Stewart Bell." Classical mechanics is always local, QM is not. That may be your personal interpretation of “Bertelman’s Socks” but not mine. When the particles involved are separated by a distance beyond the range of a “light speed” signal and the results are both random and always correlated like coin flips on two continents, the results are not classical. They demonstrate a non-local correlation.

From your statements, such as the one above, the implication appears to be that the lack of ‘hidden variables’ implies locality. Einstein et al. suggested the hypothesis of ‘hidden variables’ as an alternative explanation to his anathema of non-locality. What significance do you find to the lack of ‘hidden variables’ if the conclusion is ‘locality’ either way. Or, is that not the way it works? This appears to a description of non-locality. How can the wavelike connection and transaction between entangled particles be something other than non-local if the timing of events is far less than space like (super-luminal). The interaction among entangled particles is a part of our material world and not just a wave function on paper. When the wave-like connection between entangled particles is lost the quantum identities of the particles involved become determinate at both ends of the connection simultaneously. There is no time interval between the events on both ends which is why I call the event non-local. Or, global if you will.

What does that mean? Bacteriophages are not given genus and species names they are identified by numbers and letters.

I would interpret “arbitrary measures” to mean that there is no established protocol for naming bacteriophages especially when it comes to the selection of letters. Generally, the first person to characterize a new virus picks an arbitrary letter from the Greek or Roman alphabet followed by the number 1 followed by the genus of the bacteria they infect. Other variants are given numbers in sequence of their discovery. There is no systematic meaning to the choice of letters.

This is absolutely not my understanding. I agree that QM is probabilistic and I have never claimed otherwise. ‘God roles the dice’.

This is a quote from Wiki, “Physicists such as Alain Aspect and Paul Kwiat have performed experiments that have found violations of these inequalities up to 242 standard deviations.[20] This rules out local hidden-variable theories, but does not rule out non-local ones.” https://en.wikipedia.org/wiki/Hidden-variable_theory As I said earlier, ruling out “hidden variables” leaves non-locality as the default explanation. It also rules out and the determinate nature of entangled particles prior to observation. The quantum identities of entangled particles are random and indeterminate prior to their first observation. 'God roles the dice.' Einstein et al. rejected the idea of “Spooky action at a distance” so they proposed the hypothesis of “hidden variables” to explain the apparent non-locality as a local interaction due to a "something" common to all local environments that affects the outcome of experiments in remote locations. Now you and “joigus” appear to be saying that the absence of hidden variables rules out non-locality which is the opposite of the historical conclusion. How bizarre, how bizarre.

Sure. It's the main theme of my cover photo. Not that you noticed, I know. I've spent a great deal of time thinking about spectral analysis. There are two definitions of "projection". One is about light and another is the name of a defense mechanism. I find the first sentence is contrary to the conventional interpretation. If there ARE “hidden variables” we would need no non-local interaction to explain correlations. Hidden variables would provide the explanation. Tests of Bell’s Inequalities ruled out the presence of hidden variables so non-local interaction became the default explanation. The second sentence appears to assume that spin eigenvalues exist prior to observation but experiments suggest that they do not. This is classical physics and the now discredited assumption found in the EPR paper. Entanglement is an exception where what happens to one particle instantly affects its entangled partner no matter what the distance. They could be galaxies apart. The second sentence appears to assume that spin eigenvalues exist prior to observation but experiments suggest that they do not.

Not exactly, the act of measurement caused the instant (superluminal) loss of entanglement between the particles (decoherence) and the particles emerged with identifiable spins. The spins were indeterminate prior to the first measurement and became determinate, instantly, and at both ends, with the loss of entanglement. The conventional explanation is that they were in a state of “superposition” prior to observation. I suspect the particles were spinning before entanglement but one question is, ‘Are the spins after entanglement the same as they were at the beginning or was their emergence anti-correlated but random? I favor the random interpretation. There is always something anthropometric about our observations of quantum events. We can not measure an event without disturbing the quantum status quo and one observation initiates changes. I'd like to hear about it. Yes, they did test the dead/alive cat thought experiment but not with a cat or a radioactive isotope. The first tests were statistical tests of Bell's inequality with anti-correlated photons. Instead of dead/alive cats they used entangled, this-way/that-way polarized photons. The results suggested that a photon is neither polarized one way or the other until first measured like Schroedinger's dead/alive cat and the quantum identities did not become fixed until the instant of the first observation.

Speed IS a ratio of distance over time so a ratio can be a speed. But not all ratios of distance over time are necessarily a speed. Some say c is the speed of causality. That last point is an understatement. I know from experience. One issue is that the true speed of light is unknown and unknowable. Our units of distance, time, and the value of c are all mutually defined. The length of a meter is defined the distance light travels in 1/c seconds and a second is defined as the time it takes light to travel a c number of meters. Consider the absurdity of trying to measure the speed of light over the distance of a light year. This is the conundrum of trying to measure the speed of light. The cat is a macro object so QM does not apply but something similar happens at the particle level.

Where were you when we discussed this before? I can agree that the correlations are initial and the spin states are indeterminate. But are the spin states fixed from the start like a pair of gloves or are they in a state of alternate flux like two pendulums swinging in alternate directions? You never made this clear despite my asking. I favor the alternate flux view even over the conventional view of superposition. Does the word "projection" sound familiar? You got it. Are you saying that entanglement where two remote particle are connected as if they were side so that an action upon one instantly affects the other, is not a superluminal connection? I agree with Ernst Mach that the invention of ad hoc conjectures "metaphysicals" to explain physical events should be avoided if at all possible. It is better to leave the "unknowns" unknown if we want to progress. The danger is that conjectures tend to become "reality" with time and conjectures tend to compound over time. Conjectures are used to explain more conjectures. Do you have anything specific in mind?

Thank you for the encouraging words Here is a quote about an old experiment from one of the books in my personal collection. “THE NON-LOCAL UNIVERSE” by Robert Neadau and Menas Kafattose Oxford University Press 1999 p.4 “The “observed” phenomena in the Aspect and Gisin experiments reveal correlations between properties of quanta, light or photons, emanating from a single source based on measurements made in space-like separated regions. What cannot be measured or observed in this experimental situation, however, is the total reality that exists between the two points whose existence is inferred by the presence of the correlations. When we consider that all quanta have interacted at some point in the history of the cosmos in the manner that quanta interact at the source of origins in these experiments and that there is no limit on the number of correlations that can exist between these quanta, (4) this leads to another dramatic conclusion- nonlocality is a fundamental property of the entire universe.” The experiment by Aspect and Gisin was an experiment testing Bell’s Inequality in 1972 at the University of California, Berkley Were Alice and Bob able to send a signal? No. The non-local signal was not between Alice and Bob it was from one quantum particle to its entangled partner. Forget Alice and Bob. Your thinking is totally anthropomorphic if you think a signal can only be a signal if it sends a message from one person to another. The signal under consideration was between two entangled particles. Whether it was understood by two humans is irrelevant. When one particle was measured to be spin-up the other particle instantly responded by becoming spin-down. Both particles “got” the message instantly. The signal was non-local at the quantum level. It could only be observed to have been non-local at the macro level by means of an after analysis of the events. I suspect we may be discussing two different signals? One was non-local at the quantum particle level and the other was local between macro participants, Alice and Bob.

Naturally, QM is NOT classical. One provision of Occam’s Razor is that it cautions against the addition of unknown and unobserved entities like Leprechauns or worlds beyond our own to explain a hypothesis. In this video Sabina Hossenfelder explains why MWI is not science. “The Multiverse: Science, Religion, or Pseudoscience?” https://www.youtube.com/results?search_query=sabine+hossenfelder+multiverse And for @joigus, Hossenfelder cautions against confusing math with reality. I am a gadget person. My gold standard for truth is if a hypothesis can be reproducibly tested or observed. The non-local and super superluminal nature of entanglement has been demonstrated at CERN and a number of other laboratories around the world so that works for me. https://www.technologyreview.com/2013/03/07/179528/chinese-physicists-measure-speed-of-spooky-action-at-a-distance/ I don’t see instant action at a distance as a violation of anything in SR with the single exception of Einstein’s second postulate where nothing can travel faster than the speed of light. The second postulate is a provisional statement and it does not work as a law of physics. Faster-than-light need not extend into the main body of SR if we recognize c as a dimensional constant of space and time rather than as a speed. The value of c serves as a universal constant for converting between units of distance and units of time. The constant c is essentially the length of a standard meter expressed in seconds. It is a ratio and not a speed, and in SR, c works perfectly well as dimensional constant but it acts nothing like a speed. This is why c is the same for all observers independent of their own velocities. Nothing can go faster than c because c is a ratio and NOT a speed. Nothing can go faster than a ratio just as nothing can go faster than 1.6 km per mile. If c were a speed c +/- v should be possible. Whether we choose to call c the “speed of light “ or a “dimensional constant” the numerical values are identical so none of the math is changed. This change in perspective simplifies SR and it eliminates the paradoxes such as the “Pole in the Barn”. A slight modification to the wording of the second postulate could set everything right. Olaf Roemer observed the planet Jupiter and its moons and discovered c as the constant ratio between units distance and units of time and he mistakenly called it a “speed”. Unfortunately the misnomer has carried into SR. The “flip” involves going from an indeterminate state of superposition to a determinate state.

Yes, something is "real" if it can be explained by interpretation. But, what is 'real' for one may not be 'real for another'. Do you know the interpretation of this quote from "MigL"? If not, read the article or other articles about MWI and see if you agree. The interpretation holds that entangled particles are in superposition as are their observers. An observer in one world is in superposition with an observer in another world. But in a universe other than our own. When one observer measures his particle to be spin-up, his entangled Doppelganger in another world measures his particle as spin-down. In an instant, entanglement is lost between both worlds and they become separate entities. However, the events appear entirely local from the perspective of each world. I like speculation but that is a little over the line for me. The connecting particle fields interact non-locally such that the particles are essentially side-by-side. The connecting waves are not energy bearing so there is no energy passing from a to b. An energy exchange may be possible but that gets into a real can of worms.

I like to think indeterminacy as a coin spinning in the air. We cant give it a call until it lands. I think superposition can better explained but the idea works so I’m not about to dispute it. It’s an omen but watch for the little black tag at the bottom that reads “ Paste as plain text instead” when you enter a quote. Entangled particles are connected non-locally and by a likely Schroedinger wave-like connection. The loss of this connection is instant for both particles. This is not a light signal.

Entanglement is non-local and non-local interactions are superluminal. That means that two entangled particles can interact instantly as if side-by-side no matter what the distance between them. If one flips up the other instantly flips down and the change takes place superluminally. This never happens in the macro world. In the macro world, two observers are always have a “space-like” separation. That means that if they are separated by space they are also separated by a c/d amount of time... “spacetime”. This makes superluminal communication at the macro level absolutely impossible. Once entanglement is lost, the particles become independent of each other so that any change to one has no effect on the other. No telling if it's the suggestion at play, but yes I found it peculiar; isn't that pointing at the entanglement having a non-local character? I need to re-read, I can figure, I did not understand the whole discussion. I don’t understand it either. I think eliminating the space-time factor would make any interaction non-local. That is what non-locality is- no spacetime between. “joigus” has yet to explain how this is local.

Two questions. Why would you pick an article from such a sketchy source as a Many-Worlds Interpretation article to support your opinion. And what is your opinion of the MWI. I am aware of two cosmologies where non-locality is not possible. One is the Many-Worlds Interpretation MWI and the other is Superdeterminism. I vaguely recall the nature of these cosmologies, but as I recall, in the MWI when one of a entangled pair of particles is measured to be in the spin-up position, there is an identical entanglement in one of the many alternate universes -remote from our own- where an identical particle is measured to be in the spin-down position. So one particle is spin-up and another is spin-down but in alternate universes. I also clearly recall an article by John Cramer in which he thoroughly trashed the Many Worlds Interpretation. In the Superdeterminism cosmology, the present and past are like a movie running in the projector and our reality is the scene that is playing out so there is nothing we can to change events since our reality is that movie.

The main calculation you gave me is the same calculation physicists give to explain non-locality. The same maths that work for non-locality also work for locality. That means the many renowned physicists may be right. The quote below is what I said. And here is what you said. Show me where I failed to understand the problem, misinterpreted your words, or came to the wrong conclusion. It doesn’t take long to look up what the current authorities are writing or saying about commonly discussed topics such as non-locality or entanglement. Naturally, understanding takes longer. You never responded when I asked you the question… so now its my turn? Einstein’s view of non-locality works for me. “Spooky action at a distance.” Non-locality is a non-observable time interval between an action and a reaction because the timing is either instant or far too fast to measure. It is instant action at a distance.

Not at all and you side-stepped my question. I don't find your explanation of the bicycle story to be an example of of either interpreting correctly or reaching the right conclusions. Here is your explanation. I find the bicycle story to be intuitively simple even without any math. A heavy rider is at a big disadvantage when climbing a hill because he has to input so much more energy to get to the top. When he is at the top, he has more potential energy with which to overcome the friction when going down. Therefore he can go faster. The acceleration is not that different because of the force of friction. The heavier rider has even more wind friction because of his speed. The potential energy of the riders is the dominating factor. As for the rest of our discussion: I don’t see where you have been addressing the problems at hand with much more than unsupported personal opinions. Why do the same math examples you give not work with non-locality as well as with locality? How do you define non-locality? I think a quick view of the literature will show your views to be to be long out of date. Things like the non-locality of entangled particles, and the super position state of entangled particles prior to their measurement are the commonly accepted, mainstream views. Not that that makes it right. And, can you support your views with anything more than just personal opinions?

Then you certainly don't understand the question. 12√(|↑↓〉−|↓↑〉) independently of the space-time factor of the state. In fact, the space-time factor of the state is completely omitted. Don't you find that peculiar? What you are saying is largely what I am saying so I do find it peculiar because what you are saying sounds like non-locality. "Independently of the space-time factor of the state. In fact, the space-time factor of the state is completely omitted". That sounds like what I would call non-locality. If two entangled particles are moving in opposite directions and beyond the range of light speed communication, Observing the identity of particle A as spin-up instantly fixes the identity of its partner B as a predictable spin-down. How does particle B “know” what has happened to particle A? Or, how would you explain it without non-locality. This appears to be an overly broad a generalization that may apply to entangled particles or entangled particles in quantum computers but normally particles have a largely predictable nature otherwise there would be nothing but chaos. All electrons may look alike but Nature at least "knows" where they are.

A doesn’t “change” its identity, since it doesn’t have one in the first place. Its spin is not determined until the measurement That is a valid point but when A was entangled with AB its spin could have been either up or down. But when the particles are in a three way entanglement D-CB-A and particle D is observed to have a spin-down, that collapses the wave function for all the particles which fixes the observation of A to a predictable spin-up. This is why your gloves in boxes model does not work for entangled particles. Gloves have a fixed identity before observation but entangled particles do not.

I have a lot of respect for Gell-Mann but two things made me suspect his views. One was that they appeared to be based on the long discredited EPR paper and mainly because I find non-locality to be a long established reality. I can agree with that. I don’t find that “well-defined at all times” applies to quantum identities which are an entirely different matter. I don’t see your point. What principles of QM make quantum identities constant at all times or rule out the possibility of non-locality? Have you heard of “identity swapping” where entangled particles non-locally swap identities? Quantum teleportation is an example. Consider this possibility. One can generate two entangled particles A and B. Later they can generate two more entangled particles C and B. Then if they entangle particles B and C, the result is a four-way entanglement ABCD. As with single entanglements, the pairs are all anti-correlated. A multiple ABCD entanglement is called a GHZ state named after the first experimenters to study multiple entanglements Greenberger, Horne, and Zeilinger. If one measures just the identity of particle D as spin-up, they can predict the identity of particle A as spin-down. Since particles A and D are always anti-correlated, this means that particle A must change its identity half the time to conform to the later ABCD pairing. This and several other experiments suggest that quantum identities are not fixed at the moment of their origin but they only become fixed at the first measurement. This is why entangled particles are considered to be in a state of superposition prior to observation. In QM, the cat is neither dead nor alive until examined.

I think we are largely in agreement about the impossibility of rotating a signet state. Swansont mentioned something about contemplating a rotation of the signet state so I mentioned Kracklauer’s paper where he described entanglement as a rotation through Q-bit space just to indicate that I had given rotation some thought but I also thought I made it clear that I did not share Kracklauer’s view. On other matters, if I understand correctly, your view is that that there is nothing superluminal about entanglement? Could you explain? Also, I mentioned that the general consensus about entanglement is that the particles involved are in a state of superposition prior to their first measurement. I qualified this statement with my view that it could be better explained. I got some contrary opinions about this but a quick Google search should indicate that the main stream, hyper peer reviewed, everybody knows it, consensus of opinion is that entangled particles are in a state of superposition prior to their first measurement and this has been the case for many years. I don’t always agree with Don Lincoln but his video below is one I can agree with from start to finish. https://www.youtube.com/watch?v=JFozGfxmi8A He explains why entanglement is superluminal, why the gloves/ balls in a box analogy is not valid, and rather than saying the particles are in superposition, he says their spin directions can be in any possible direction governed by their common wavefunction. This is essentially the same thing but better than saying they are in a superposition of both spin directions at the same tine.