bangstrom

Nope. They showed that at least one of both, locality or realism is not valid. All my bulleted authors above say, or tend to, give up on realism, especially Zeilinger himself. We obviously have different interpretation of what some of there authorities have said. As for realism, I say realism is dead, you say realism is dead, Zeilinger says realism is dead. Everybody agrees that realism is dead. What is your fixation about realism that you keep bringing it up again and again. Can you state your point and move on? Exactly. Especially, they say nothing about a signal. The equations said nothing about a signal or the timing of a signal that is why I found them irrelevant. You are arguing in ill faith. Where CHSC clearly distinguish between the two assumptions, locality and realism, you are suddenly talking about 'locality' and 'local realism'. It was already explained to you ad nauseam that in CHSC 'local realism' means 'locality' and 'realism'. What is in ill faith? I understood that CHSC distinguished between locality and realism BEFORE you clowns tried to explain it again, and again, and again. What is your objection about local realism? Local realism and realism were both violated by The Bell test so realism is violated simultaneously by different names. And what is your obsession with the violation of realism. Everyone agrees that realism is dead, dead, dead but you keep bringing it up ad nauseam. What is the point you are trying to make? These things appear to violate Einstein et al's. EPR article where the individual quantum states are determinate. Do you still claim that the violation of realism does not invalidate Einstein's view of realism?

What do you mean spontaneous? You mean parametric down conversion of photons? It's essentially the same case we've been discussing all the time. Spontaneous parametric down conversion is something we have never discussed here because it is difficult enough to explain the results of quantum experiments without getting into the methods and SPDC is used in nearly all quantum experiments. Down converted UV photons are not parametric until passed through a red filter so it is proper to to leave off the parametric part. SPDC involves passing a powerful UV laser light through a beta-barium borate crystal BBO to generate pairs of entangled photons. When a molecule of the crystal absorbs a UV photon it SPONTANEOUSLY emits two photons of lower energy. This happens much less than one time in a billion so it is a rare event called DOWN CONVERSION. Two entangled photons of equal wavelength are necessary for experiments. PARAMETRIC means they have equal wavelengths. So a UV light passes through the crystal and rarely a pair of red entangled photons emerges. The red filter allows the photons to pass through without destroying the entanglement because it is not actually a measurement.

The mentioned equations say nothing about the timing of events between entangled particles when one is observed. I don't see the relevance. CHSH states that either a violation of locality or a violation of local realism would indicate that entangled particles do not have definite values before observed as is necessary for the EPR hypothesis to be correct. You may say that realism is violated and I ask, Why? I say the preponderance of experimental evidence in favor of non-locality is evidence enough for dismissing local reality. In either case, the EPR is no longer valid. Or would you disagree?

Relativity is correct but Einstein’s second postulate has an exception when it comes to the transactions among entangled particles needing to be no faster than light speed. No, they did not demonstrate the 'reality of non-locality'. They demonstrated the absence of local realism. You can twist and bend that as much as you like, but they are NOT equivalent. The absence of local realism was demonstrated by the violation of Bell’s inequalities that showed entangled particles do not have definite values prior to their observation. The demonstration of a FTL signal between entangled particles is another observation that could violate local realism so either type of observation could do the job. If one entangled particle is observed to be spin-up the other particle is instantly known to be spin down. This suggests some form of instant transfer of information from the observed particle to the unobserved particle if the the other particle is certain to be anti-correlated. But, perhaps not, there may be something to the entanglement that guaranteed the particles would be anti-coordinated when observed. Zeilinger demonstrated with his quantum teleportation that the unobserved quantum identity of the second particle can also be determined by an even later entanglement nullifying the ability of the first entanglement to decide the anti-coordinated nature of the entanglement. This strongly suggests a non-local signaling among entangled particles. Quantum computing involves entanglement for some things such as security keys. I am having trouble getting this citation to work for details about qubits of information but you can look for: Videos of Susskind Lectures #1 of #1 bing.com/videos Or Leonard Sussikind Lecture 1|Quantum Entanglements, Part 1 (Stanford) This will probably lead to a long series of videos. Look for the one with Sussikind standing in front of a hand drawn grid. Skip the first 6 minutes. If you know the before and after you can tell if the states have been reversed. If you go to Pisa Italy and find the Eiffel tower where the Leaning tower once stood, you know something has changed.

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

What did Sussikind have to say and are you dismissing the many experiments demonstrating that quantum entanglement is non-local, 'instant'? I have repeatedly stated that we have to give up on the idea of realism. Where do you find a difference in our views? 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. I have frequently given the official description of the signal. It is defined as a single qubit of quantum information. 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.

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. 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. Correlation is an effect and not a cause. 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? 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? 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.

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

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

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. 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. 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.

Experiments such as the one you are asking have been done many, many times and with greater accuracy over the years. The observations are that A and B can't be far enough apart and the measurements can't instant enough to change the expected outcome. By comparing the shortest times between measurements and the distance between A and B it is possible to find a lower limit for the time of the interaction compared with c. https://newatlas.com/quantum-entanglement-speed-10000-faster-light/26587/ https://www.scientificamerican.com/article/china-shatters-ldquo-spooky-action-at-a-distance-rdquo-record-preps-for-quantum-internet/ https://www.newscientist.com/article/2134843-chinese-satellite-beats-distance-record-for-quantum-entanglement/ "Quantum entanglement, one of the odder aspects of quantum theory, links the properties of particles even when they are separated by large distances. When a property of one of a pair of entangled particles is measured, the other "immediately" settles down into a state compatible with that measurement. So how fast is "immediately"? According to research by Prof. Juan Yin and colleagues at the University of Science and Technology of China in Shanghai, the lower limit to the speed associated with entanglement dynamics – or "spooky action at a distance" – is at least 10,000 times faster than light."

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. 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.”

"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 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? 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? Did you figure that out by yourself? I said the firecrackers were together, twisted fuses and all. If they were separated the observations would be different. Who’d a thunk it. 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?

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.. You have four observers, who because of SR have four different views of the timing and they may have even been able to observe which firecracker they think went first. The problem is which observer caused one firecracker to go before the other. I would say none of them caused the event because all observations were made after the event. Is that clear? Looking at an experiment, Alice and Bob are one light second apart. A...................................................................Source...................................................................B <-- one light second apart --> The dotted line is the non-local wave function between the two entangled particles. If Alice measures her particle one nano sec. before Bob, this instantly fixes the quantum identity of Bob's entangled particle so it is anti-correlated with Alice's particle. If Bob measures his particle one nano sec. after Alice, somehow his observation should be anti-correlated with hers. It is not necessary that Bob know what Alice's observation was or that he know his observation was not first and he need not wait for a light speed signal to reach his location. The entangled particles 'know' how to respond to the loss of entanglement and that is what matters. 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 observations of outside observers do not switch which observation came first because the die is cast with the first local observation. I have explained this several times before in bits and pieces but here it is it is in one post

Why do you think I don’t understand? Initially, Alice think she is first and Bob thinks he is first but it maks nix. The wave function decides.

It is really amusing to see how you shoot yourself in the foot again and again. At about 10:05: I think we need to abandon 'realism' at the quantum level but not at the macro level because that is where it works- nearly all of the time. I never felt I understood the nature of light until I encountered non-locality and then all the things that never made sense before began to make sense. Non-locality also simplifies the explanations of SR without changing it one bit except that all of the light related paradoxes vanish. That is, things like the ‘Pole in a Barn’ paradox that only adds to the confusion.

I haven’t been ignoring the “suggestion”. I just don’t follow the practices here of saying you are wrong and confused and your idea is garbage if I disagree. Nor do I think unsupported personal opinions pass for expertise. I don’t find these things very convincing and many others in other science forums must not either since personal comments and unsupported opinions are less infrequent. I keep saying the violation of the Bell test has ruled out the possibility that anti-correlation among entangled particles has a classical explanation So, the “suggestions” to the contrary are wrong and confused and garbage in case anyone feels ignored. I don’t agree that these examples are without direct physical interaction and I can explain why but that is another topic. The Alice and Bob analogy assumes a single reference frame. Your comment about other reference frames is a ridiculous obfuscation. And, please, oh please, do learn something about QM from this past half century. The EPR effect is dead and non-locality is real.

That is no problem because the timing is non-local (instant) no matter which way the whatever-you-call it is going. That was the case with the early Aspect-Clauser experiment and many others but they were only looking for anti-correlation among entangled particles, in which case, it didn’t matter which detection came first. The signals were detected as anti-correlated before a light speed signal could reach opposite ends of the experiment indicating that the connections were non-local. You are right right. That is a perfectly good explanation for correlation and there are many experts who would agree with you. Hold that thought and consider the implications. Bell did the math and theoretical work. Aspect and Clauser did the experiments and Zeilinger came along much later.

The experiments of Bell, Aspect, and Clauser demonstrated that entangled particles are non-locally connected so that if you measure one entangled particle you instantly fix the quantum identity of its partner. Einstein was demonstrated to be wrong about his idea that any change to one particle could never affect a change to another distant particle without a direct physical, light speed connection. “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." https://phys.org/news/2022-10-quantum-entanglement-physicist-science-einstein.html

Here are two You Tube videos from the last few days. The first one from IBM’s Qskit explains Bell’s inequality and some of its implications. It also explains how the violation of the Bell test demonstrates that non-local correlations are not classical. "Bells Inequality: the weirdest theorem in the word | Nobel …" https://www.youtube.com/watch?v=9OM0jSTeeBg The first part of this video below is from Sabina Hossenfelder where she explains non-locality “Spooky action at a distance.’ and how it is real. https://www.bing.com/videos/search?q=Sabina+hossenfelder+videos%2c+what+is+spooky+action+at+a+distance&docid=14063314246435&mid=B10F06990A26C1994BEFB10F06990A26C1994BEF&view=detail&FORM=VIRE

I forgot to mention that Alice and Bob are assumed to be in the same local, inertial reference frame. We can choose a local reference frame, but of course, I understand there is no preferred reference. That is basic. Perhaps you got confused by my mention of space-like time. If an event happens at at one time, and another event happens the next day, the clock timing of the two events is called 'time-like.' However, if two events happen at exactly the same time. Say, one event happens on the moon and another event happens on Earth, the time-like separation between the two is zero because they are simultaneous but we know from SR that there is an observed space-like clock time separation of about one second for every 300,000 km of distance. This has nothing to do with the lack of a universal frame of reference. If Alice and Bob share the same inertial reference frame, the space-like time between the should be exactly the same for both. With space-like time, near events are only a short distance away in both space and time (spacetime) but remote events are farther away in space and time. There is a name for that observation and it is space-like time. Are you saying that is what I don't understand about the experiments?

Where did you get that crazy idea. Abandoning local realism involves abandoning the principle that all local change must be mediated by a direct physical connection. Abandoning the principle of realism involves abandoning the principle that we live in an objective reality. Abandoning the idea that two entangled particles connected by a common wave function in which there are no particles is what meant by abandoning common sense. I have explained this several times before and it is so simple it should need no explanation. The observers at the opposite ends of the experiment have absolutely no way of knowing which measurement came first until later when they can later gather their information together. But it is possible to say which came first before that. Just ask the experimenters which observation they chose to measure first. The repeated observation that entangled particles are anti-correlated when they drop out of entanglement suggests that the entanglement must have been signaled or at least maintained by some sort of information that that kept the particles anti-correlated throughout the entanglement. For example, when two particles A and B are entangled even though they might be light years apart. A measurement made on either one of the entangled particles instantly destroys the entanglement for both of the entangled particles and their quantum properties which were indeterminate before (superimposed) instantly become determinate. This observation suggests that there must be some sort of wavelike connection between the two remote particles that maintained their their quantum properties as anti-correlated and even though the two particles may have been out of range of a light speed signal at the instant when their entanglement was lost. With the loss of entanglement (decoherence) the previously unobserved particle somehow instantly 'knew' a quantum property of its entangled partner had been observed and it presented a similar quantum property that was anti-correlated to the newly presented property of its former partner. This suggests some form of a non-local exchange of quantum information often called a 'signal'.

The “faster than light” and the “instant signals” parts go by different different names such as ‘spooky action action at a distance’ or ‘non-locality, or ‘instant interaction’ . The violation of the Bell test rules out the possibility of classical ‘hidden variable” explanations for the above examples above that are permitted by quantum physics but not classical. If the three Nobel winners had discovered that the observations of their experiments invalidated the possibility of instant action at a distance and that this was a non-real artifact of classical physics, there would be nothing remarkable about their discoveries. The disappointing part of their discoveries is that the remarkable parts are only possible at the quantum level and are so far of little use for macro level for such things as FTL communication or Star Trek style teleportation. The exceptions may be for high speed quantum computing and for computer encryption. The properties of B are random not fixed prior to the first observation. The observation of particle A fixes the observed property B as anti-correlated to that of A. If A and B were both random they would not necessarily be anti-correlated. This is not classical because the quantum properties are not fixed from the start. Do you remember the gloves in boxes thought experiment that didn’t work with QM. The violation of the Bell test ruled out the possibility that the quantum properties are fixed from the start. The instant loss of entanglement on both ends is the signal.

If you have a particle A and a particle B a considerable distance apart. The quantum properties of A are are said to be in superposition with particle B as long as the two are entangled. If you observe any one property of either A or B, the Bell test tells us that the observed properties are perfectly random. The Bell test is a statistical test and it is difficult to explain but explanations are easy to find and not terribly difficult to follow. So, for now, just assume the Bell test is correct and the and the quantum properties of entangled particle are random. If you observe a single particle, for example, observe particle A for spin direction, it can be observed as either spin-up or spin-down but the spin orientation before it is observed is perfectly random. If the spin of particle A is observed to be spin-down that means the entanglement with particle B is broken so the quantum properties of B are now fixed and no longer random. We know that, if the spin of particle A is spin-up, the spin of particle B must be spin-down unless something happens to disturb particle B after the loss of entanglement. But, as long as particles A and B are entangled their quantum properties are anti-correlated. This is all basic stuff of QM that has been known for many years and well described in many sources. Now to answer your question. If particle A is spin-up, particle B must be spin-down when entanglement is lost. The question is, "How does particle B 'know' it should should be spin-down and when did it 'know' it? There must have been some message to the wave function that kept the two particles anti-coordinated while entangled. It could be a light speed a signal that maintained anti-correlation, in which case, the spin of particle B could be observed as either spin-up or spin-down when observed since the quantum properties of entangled particles are random until observed The light speed hypothesis has been tested by observing the the spin of the unobserved particle B before a light speed signal had time to reach B and let it 'know' that particle A has been observed as spin-up so now it should be spin-down. This is where something superluminal is happening. Again, this is all old news and forests have been destroyed to explain how it works.

The timing between the signal and its reception is instant. There is no time or observation to be made between the signal and sink so there is nothing to elaborate upon. I would like to claim prescience for finding a violation of of Bell’s inequality, for demonstrating non-locality and for the details of signaling by qubits of quantum information but unfortunately the three winner’s of this year’s Nobel prize have the preponderance of evidence that they thought of it first with their experiments. You may not be able to Google my pet theory but you can Google about why the three won this year. Is that why you are so reserved? Sorry, I didn't comment on your statement with so much going on at the time. You may be surprised that I agree with what you said. This is for both you and Joigus since he asked the same question. We know from SR that a spacelike separation is one second of time for every 300,000 km of distance. If the spacelike timing in an experiment is exactly the same from both locations, it is impossible to tell which came first based on that information because the two events are simultaneous. The only way to tell which came first is to ask the experimenter which end of the events they measured first. If the experimenter says they measured Bob’s end first, then Bob’s end was measured first. The experimenter is the only one making observations. Alice and Bob are imaginary so, in reality, neither one can measure anything. The numerical value for a spacelike timing and the speed of light are exactly the same, so the calculations using the value of c are the same no matter what we choose to call it. It also means that, if the time of a space-like signal between the two events when measured from both ends is is equal, the signal time was instant. The calculations remain consistent with SR with the one exception being the wording of the second postulate that nothing can travel faster than light. An instant signal is "magical" which is why Einstein called it, "spooky" and Zeilinger called it "eerie" but a non-local signal by quantum entanglement has been repeatedly demonstrated as real. That is why it has caused so much attention. An instant non-local signal may be real at the quantum level but we can only view the timing between two points separated by space as 'space-like' which makes it impossible to use quantum signaling for FTL communication.