Jump to content


Senior Members
  • Posts

  • Joined

  • Last visited

Everything posted by bangstrom

  1. Information has no energy and a signal need not be energy bearing. The question is, if an electron on one end of an entanglement is found to be spin-up, how does it's former partner in the entanglement instantly 'know' it should be spin-down? Simultaneous within the reference frame of the experiment itself and its measurements. Or, simultaneous relative to the origin of the entangled particles if you want to be really precise. The detectors are ideally widely spaced so the events will never be simultaneous to all observers but that has no relevance to the experiment or its measurements since outside observations can not change the results.
  2. That's what I said. If it matters to know which measurement came first, the experimenters can decide which to measure first. I have explained many, many times I understand this. What are you saying I don't understand? Agreed, a purely space-like separation has no timely order. Also, the term 'privileged reference frame' is specifically a cosmological term and one that I would not use in reference to an ordinary reference frame so your claim that I did had me confused. I understand the point you were making but, in reality, when two different measurements are made in the 'real' world it has to be nearly impossible to make both measurements at absolutely and precisely the same femtosecond or less so there will always be a first measured. I know you say there is no message. But I say there does appear to be evidence of a signal and response and that is suggestive of a message being sent and received so I am not convinced. Different observers seeing signals going in different directions is a well understood phenomenon of SR. It may be counter intuitive but I don't understand how it means there is no signal. It also makes no difference to the measurements at the local level of the experiment itself. . That seems incompatible with Special Relativity. Clarification: I'm sure the actual experiment is consistent with Special Relativity, your explanation is not. Agreed, changing the names to first observed and second observed or to widow and widower has nothing to do with SR. Also, the experiments with entanglement are consistent with SR because they are designed with SR in mind. They are perfectly symmetrical with pairs of entangled particles originating in the precise center between two measuring devices so the measurements on both ends are made simultaneously. This eliminates any time variations due to either classical or relativistic variations. Very much so- right from the start. Could it be that the common wave function that “defines” the correlation is a form of ‘signal’ that maintains correlation? I don’t find the view that a correlation is because “it simply is” as explanatory when the quantum identities are indeterminate until observed and entangled particles always appear anti-coordinated even when separated by a great distance.
  3. Yes, you did: 23 hours ago, Eise said: I never claimed the inertial frame of the experiment was a ‘privileged’ frame. Sorry, the first part or this was omitted so I will repeat it in the next comment. My underline. In physics, the term ‘preferred frame’ or ‘privileged frame’ has a specific meaning much different from the common usage of the word meaning favored or selected. It has a cosmological meaning unrelated to anything we were discussing. So I never claimed my frame was ‘privileged’. Using a local reference frame to the exclusion of others is a normal and accepted practice. It is absolutely not the same as a ‘preferred frame’. A ‘preferred frame’ is a global reference frame that unifies all reference frames. Various preferred frames, such as the CMBR, have been proposed but so far they have all been proved unworkable so there is really no such thing as a preferred frame. This is from Wikipedia, "In theoretical physics, a preferred frame or privileged frame is usually a special hypothetical frame of reference in which the laws of physics might appear to be identifiably different (simpler) from those in other frames. In theories that apply the principle of relativity to inertial motion, physics is the same in all inertial frames, and is even the same in all frames under the principle of general relativity." If it is necessary to know which measurement came first, the experimenters can decide which measurement to make first. Easy-peasy. Usually it is not necessary to know which came first and the measurements may not be able to determine which was first but that only means that the timing was below the device's threshold of measurement. On the other hand, when one particle is measured, the other responds correctly by being predictably anti-coordinated so the second measured particle apparently ‘got the message’ no matter how quickly or beyond measure the timing was. I nowhere said such a thing. If you think I did, cite the relevant text passage. That was one of MY explanations for why SR considerations are neither relevant nor used in the the calculations. I made no claim that you said that. You would have been right if you did. My underline. In physics, the term ‘preferred frame’ or ‘privileged frame’ has a specific meaning much different from the common usage of the word meaning favored or selected. It has a cosmological meaning unrelated to anything we were discussing. So I never claimed my frame was ‘privileged’. Using a local reference frame to the exclusion of others is a normal and accepted practice. It is absolutely not the same as a ‘preferred frame’. A ‘preferred frame’ is a global reference frame that unifies all reference frames. Various preferred frames, such as the CMBR, have been proposed but so far they have all been proved unworkable so there is really no such thing as a preferred frame. This is from Wikipedia, "In theoretical physics, a preferred frame or privileged frame is usually a special hypothetical frame of reference in which the laws of physics might appear to be identifiably different (simpler) from those in other frames. In theories that apply the principle of relativity to inertial motion, physics is the same in all inertial frames, and is even the same in all frames under the principle of general relativity." It is more like they are soft-wired since we know nothing about the properties of entangled particles until observed and then it all comes together. In the actual experiment, the first particle observed instantly makes the other particle the second particle to be observed. You should write a paper.
  4. I was discussing two objects in ordinary space. You assumed I was discussing a diagram. I was not discussing a diagram so the confusion was on your end. I never claimed the inertial frame of the experiment was a ‘privileged’ frame. As usual, it was a frame of its own. I said the particles ‘know’ which was measured first. That was a teleological statement but how better to say it? If you understand SR, you should know that observers from outside a single reference frame can not go back in time and change events that have already happened to conform to their various outside observations. The "people" in this case were telling me SR applies across reference frames. I was saying that ain't so. This sentence doesn't make sense gramatically, let alone physically. A cohort is a set. An ‘entanglement’ is a ‘set’ of two or more particles that may be widely separated in space but they act as if they were side-by-side.
  5. There are no cohorts among quantum properties but there is a non-local connection among entangled particles that maintains correlation. Are you implying that entanglement itself is a cohort? Non-local updating of the system without ‘hidden variables’ is a generally accepted principle of QM. The non-local updating of the system is what Einstein objected to as, “Spooky action” but it has been routinely verified as a real effect ever since it was first demonstrated by Bell. Why is this not an interaction? It represents an updating of the system itself. Your observation tells you that the system has been updated but the system was updated whether you are aware of it or not. Experiments involving entanglement work over both large or small distances and there are no 'hidden variables' in position.
  6. I don’t know if you noticed but the first part of my statement was self contradictory because I inadvertently omitted a word. I intended to say interacting particles can not have a space-like separation. In the second part, where I said that any two particles in different locations have a space-like separation, I was referring to different locations in the usual sense of ‘different locations’ not to locations on a diagram. So your comments about diagrams do not apply. I made a statement that, with entangled particles, the “first particle observed” breaks the entanglement for both particles simultaneously. The result was that everyone, including yourself as I recall, were claiming that different observers see space-like events differently so no one could say which observation came first therefore I was ignorant of SR because I ignored SR in my explanation. I agreed that remote observers may not know which came first but the “particles know” which was ‘first observed’ and no outside SR observations could change the order of events. I don’t know if anyone got the message that SR was irrelevant to the problem because the bickering about my omission of SR continued for much longer than it should have. I was not aware that a space-time diagrams should plot events and not physical objects. You can't have events without physical objects so I would would think plotting one would be redundant to plotting the other. All the light cones I have seen, do plot physical objects and they plot them as world-lines. Never as points. I was not aware that my arguments are so vague. Could you point which of my depictions of a space-time diagram got you so confused, or in the future, let me know when my arguments are vague.
  7. It is simply not true that every particle, given enough time, will eventually interact with another particle. Two photons that are being lost beyond the cosmic horizon in opposite directions, eg, will never meet again, or interact in any way. You are reading something into it that isn't there. Each photon will eventually strike another particle. Not necessarily the other photon or any specific particle. Just another particle. I don’t agree that a local interaction is required to initiate entanglement although that is necessary for experimental sources. Any non-local, two-way interaction among particles, usually electrons, such as Cramer’s advanced and retarded potentials constitutes an entanglement. If you can have numerous observers in different inertial reference frames all claiming a different timing and different orders of the same event, I call that “ambiguous”. That may not be the best word but it appeared to be a fit regurgitation at the time and it was mine. That sounds like a line from my gazpacho in support of Bell’s analysis. To continue: I say the observation of one property determines nothing about the possible outcome of any of the others, with the one exception of the same property to be observed with the other entangled particle. I think our difference in opinion is with quantum properties having cohorts. Classical objects have cohorts but quantum particles do not so any of the combinations in your “Collectivity (2)” are possible. No quantum properties necessarily go together. If you have a quantum coin that is heads on one side and tails on the other- and red on one side and blue on the other- you can get Heads- Red one time and Heads-Blue the next. Quantum properties do not cohort and that is the Bell test.
  8. Yes, for space-like separated events, timing is ambiguous but the ambiguous nature of SR events for different observers can not reverse or even slightly affect the order of time-like events. You and others were trying to tell me some discussions ago this is possible but I still say outside observations can not go back in time and reverse the order of events that have already happened. I thought this was eventually understood but you raised the issue again. I agree with Bell that the many kinds of variations such as those found in your "Collectivity (2)" are observed with observations involving entangled particles. The observation of one quantum property can not indicate the possible nature of any other of the several quantum properties. They can all vary independently and this indicates that they are not fixed from the start. There are no cohorts among quantum properties as there are among classical properties and every observation is random.
  9. The outer bounds of a space-time diagram are the propagation distance of a light flash and the inner contents of a light cone can include anything within the entire visible universe. The light cones themselves are imaginary constructs and it is legitimate to populate the cones with any ‘objects’ relative to the discussion. The contents of a light cone are not limited to events alone and other contents frequently include particles, world world lines, smaller cones, and even space travelers as with illustrations of the twin paradox so your assertion that the addition of anything other than events alone in not kosher with SR is without merit. No. Two photons parting away from each other will never meet. OK, but that is not what I said. The generation of an entanglement event is like the generation of a light flash. It can be anywhere an origin is possible and it makes no difference where the origin may be if you are just speaking of entanglement or light flashes in general. A major difference with entanglement is that it can begin at a single point when two particles are generated from a common source or it could be generated at more than one point as when two electrons in different locations spontaneously entangle. In that case, it would be the origin of two separate light cones but with electrons sharing a common non-local wave-like connection. Your second picture of light cones illustrates that sort of an event.
  10. This isn't what I said but close enough. What is so wrong about this statement? Essentially it says that every particle, given enough time, will eventually interact with another particle. I don't find that to be so controversial. This statement had something to do with how a thrown stone has an impact site in its future light cone but that doesn't mean it is entangled. Also, I learned nothing from your excellent discussion about light cones because it was nothing I didn't know before. We appear to be in general agreement but you missed the points where our views part company. One minor point is that particles can not have a space-like separation. I say that any two particles in different locations have a space-like separation. The only major disagreement I see is the one below. There is one remarkable exception to the rule and that is with entanglement. When two similar charged particles, usually electrons, establish a two-way resonant connection and act as if they were side-by-side, even though they may be galaxies apart, that is entanglement. Their connection is non-local and you could say they even reside in different light cones because they have no ordinary classical connection. As I recall there are some basics of SR that you never explained if I may go back and review. For one, if you have a source of entangled photons (usually a down converter) exactly in the middle of two synchronized clocks, so that two photons are generated simultaneously and they reach opposite detectors at exactly the same time, how do the observer-dependent views of outside observers affect the timing of the events. I say they have no effect on the the timing at all. Secondly, with the same setup, if one timer is closer to the source than the other so a measurement is made on the closer particle before the farther particle, that makes the closer particle the ‘first observed’ and the difference in the timing of the measurements both time-like as well as space-like. Then, as before, if an observer closer to the farther particle sees the farther particle as the ‘first observed’, how does this change the order of events and make the farther particle the actual ‘first observed’ and the closer particle the ‘second observed’? I would say the local view where the closest particle is the first particle observed still holds true and the view of an outside observer has no effect on the local observation of which came first. What is wrong with these scenarios?
  11. I asked the question because your explanations of why the particles always appear anti-coordinated only work when one assumes that they are unchanging as with the 'gloves in boxes' example or how the particles are always anti-correlated with no signal between them. I wasn't asking about the quantum properties while they were entangled. Knowing the “before” state is not necessary to observe that changes in the quantum properties of entangled particles are taking place. It is NOT necessary to know the ‘before’ state with the Bell test. The Bell test demonstrates that there are more possible outcomes of an ‘after’ observation when more than a single quantum property is observed than are possible with the classical model where the quantum properties are fixed and unchanging from the start. Are you implying the Bell test is faulty? Also, knowing the ‘before’ identity is also NOT necessary for quantum teleportation because a second entanglement can change the observation of a remote entangled particle from indeterminate to determinate. If you understand how quantum teleportation, works you should know that the instant teleportation of a single quantum property from one particle to that of a remote entangled particle is only possible if the quantum property under observation is capable of being instantly changed (teleported) from one particle to a distant particle. You may not know what the quantum property of the particle may have been without teleportation but you can reliably predict what it will be after teleportation because it will always be identical to the identity of the particle whose property you teleported. This requires some kind of instant signaling between the particles. Experiments demonstrate that the quantum properties of entangled particles are random and anti-coordinated on both ends of an entanglement and become determinate when the first particle is observed. So how does a particle on one end of a remote entanglement 'know' it should be anti-coordinated with its partner when its distant partner is observed without some kind of an instant signaling?
  12. Are you incapable of determining whether or not I said that? Or that I’ve repeatedly confirmed that the states are undetermined? I guess reading comprehension is one of the issues here. We both know entangled particles are indeterminate before the first observation is made so why tell me they are indeterminate? Quantum particles have observable properties BEFORE and or AFTER entanglement and you say they are coordinated or anti-coordinated after entanglement. The Bell test and quantum teleportation experiments tell us that any AFTER property is not necessarily the same as the BEFORE. Do you agree with this observation or not? Entanglement is not SR and think about what you said in the above. Every particle large or small is “within the absolute future light-cone of another.” If that is your understanding of ‘entanglement’ then every interaction is an entanglement so entanglement is no different from throwing a stone. I don’t know if that is what you mean but that is what you appear to have been saying the whole time. Do you recognize that there is a difference between entanglement and classical interactions? I know the problem well so take your time.
  13. Again, are you saying the quantum properties of entangled particles are ‘fixed’ at the start and unchanging? This is contrary to the Bell test and Zeilinger’s teleportation experiments would be impossible if it were so. This should be a yes or no question. More examples with macro objects will not answer the question since the question is about entangled “particles” and not macro objects after separation. Energy, spin and all other properties are conserved but are the quantum properties unchanging? Are you saying they are fixed from start to finish? I'm waiting. "So you force the quantum state to "decide" (select, einselect) what particular value of the quantity Q it --for lack of a better word-- "encapsulates." How does that 'force to decide' not involve some kind of a signal? The individual quantum properties are binary, either one state or another, and they don’t disappear with the loss of entanglement. They become determinate. What happens with the others is unknown because we can only observe one property and that causes entanglement to be lost. Would you say space-like separated particles interacting on the same light cone are local or non-local? I would call that a non-local interaction. If that is 'local,' what would you call non-local? Or, are you saying nothing is non-local?
  14. I will leave it to you to speculate about how a correlation is not an interaction? The correlation may be present from the beginning but the quantum properties have been demonstrated to be random at the first observation and instantly predictable at the second observation. If the observed properties were unchanging from the first, then the instant correlation could have a simple classical explanation but it has been determined that this is not the case. This makes it difficult to explain how a correlation can be constantly maintained from one end of the connection to the other, no matter what the distance between, without some kind of an instant signal common to both ends of the entanglement. The conventional explanation is that the quantum properties are random, indeterminate and superimposed prior to the first observation. This explains the random nature of the observation but it doesn’t explain the correlation. Some have described the connection between the two or more entangled particles as a Schroedinger wave-like connection and that implies some kind of a circular undulation like the one depicted with “Hoola’s” wave a few posts ago. If the two particles are always at opposite points of the wave function such that, when one particle is at a point that could be considered the ‘peak’ of the wave, the other particle will be at a point that could be considered the ‘trough’. This could explain how the entangled particles remain anti-correlated where opposite positions on the common wave function represent opposite quantum properties. N. “Viv” Pope explained the connection as “swapping stools” much like two persons in a game of musical-chairs with two chairs. When the music stops, each one grabs a chair but they will always be anti-correlated. The first observation is the thing that breaks the entanglement and the loss of a connecting wave function instantly ‘stops the music’ on both ends and this signals each particle to take on an identity that is appropriate for whichever its position on the wave function calls for at the time. In this scenario, the connecting wave function is what maintains the correlation and the instant loss of entanglement is the signal that ‘stops the music’ and ends the entanglement leaving the particles on both ends of the former entanglement with the appropriate anti-correlated quantum properties.
  15. The point I was trying to make is that the results are random whether you make the observation once or a dozen times. Agreed, they are always random. What do they consider to be "local interactions"? If one electron entangles with any other electron on their common light cone, would that be considered 'local'? One peculiarity of entanglement is that the particles appear to be without any space-like separation between them. Their properties are superimposed and that may be as local as anything can get.
  16. Agreed that the anti-correlations are built into the state. I question how they are maintained after entanglement when the Bell test has ruled out the possibility that the quantum properties of the entangled particles are not static. To go back to the old gloves in boxes scenario. If you open your entangled box and find a RH glove you know the other box is LH. If you could close the box and somehow re-entangle the boxes the handedness of the gloves again becomes random. If you open the box a second time and find your glove to be LH the handedness of the glove in your box has changed and you know the other box contains now contains the RH glove. How did the glove in the distant box 'know' it should be LH on your first observation and RH on your second observation? Then the correlation has become the signal. I am sorry if that offended you and I thank you for the suggestion. I meant no offense. The entangled properties are not 'set' they become random, The conventional explanation is that they are superimposed and indeterminate until the first observation is made and then they become set again until something disturbs them. Close proximity is only necessary for generating entangled particles for experimental purposes but spontaneous entanglement at a distance among charged particles (especially electrons) is normal and common. Carver Mead is THE authority on entanglement among electrons and he claims that any electron can spontaneously become entangled with any other electron on its light cone. He explains this in detail in his book, "Collective Electrodynamics" Part 5 Electromagnet Interaction of Atoms. Electrons in a molecule are entangled as are the electrons in an atomic cloud of electrons and a electron in one atom can entangle with an electron in a distant atom. "In a time-symmetric universe, an isolated system does not exist. The electron wave function in an atom is particularly sensitive to coupling with other electrons; it is coupled either to far-away matter in the universe or to other electrons in a resonant cavity or other local structure."- Carver Mead
  17. There is a demonstrable action and a predictable reaction. That is a demonstration of some kind of connection.
  18. 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.
  19. 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. 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. 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?
  20. 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. 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.
  21. 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. 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. 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. 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.
  22. 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. 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.
  23. That is right, but for me, non-locality is what makes realism a -non. OK, by me. 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. A day without your objections is like a day without sunshine. I am worried when we agree.
  24. 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?
  25. 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?
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.