Electron and Information.

[bangstrom]

Yes I can, the question is, why can't you? I provided the links, you just have to follow them. So why don't you? You have no interest in the science.

The problem is I can’t work long and hard enough to wrestle the facts into submission to see things as you see them. If you can’t point to which parts of your citations support your opinions, I can only assume that you can’t either.

LOL LOL LOL space-like intervals are outside the light cone, therefore by your own statement any causality you claim to exist over space-like intervals is part of an "imaginary zone beyond observable reality."

Outside the light cone is an imaginary zone where I can imagine causality exists just as you can imagine it does not.

Incorrect. Bell's inequality demonstrates NOTHING about the order of events, which are either fixed for time-like intervals or arbitrary (relative to the inertial frame) for space-like intervals.

The point is that there is no basis for them to agree on which was first and the only rational conclusion is that with a space-like interval between them neither of the two measurements are first. Thus there is no instantaneous causality or information transfer between the two events. There is only the agreement between the random results of simultaneous measurements. The result is not a violation of relativity or the Minkowsky limitation of causality to time-like intervals, but there is a contradiction with Einstein's premise of local realism and we have to accept that there are non-local aspects to reality.

The measurements are not simultaneous and the timing of events is part of the experimental data so, when the observations on both ends of the experiment are compared, we can discover exactly the order in which the observations were made. When the experiments are repeated many times, they are found to be in violation of Bell’s inequality suggesting that the first entangled particle to be observed instantly fixes the quantum state of the other particle.

The observation of the first particle breaks the entanglement causing the other particle to assume an anti-correlated quantum state. If one particle is observed to be spin up, we know that the other particle is now permanently in the spin down position. This is contrary to Einstein’s local realism and evidence of non-local action at a distance.

http://courses.theophys.kth.se/5A1381/r ... chuetz.pdf
"We will see that things are different in the ’microscopic’ world, i.e., the two atoms do not decide which of them has spin 1 and which −1 until a measurement is performed."

[mitchellmckain]

Yes I can, the question is, why can't you? I provided the links, you just have to follow them. So why don't you? You have no interest in the science.

The problem is I can’t work long and hard enough to wrestle the facts into submission to see things as you see them. If you can’t point to which parts of your citations support your opinions, I can only assume that you can’t either.

Looks to me like a tactic of wasting my time. But ok, I will do the first one, which is Wikipedia on causality.

In modern physics, the notion of causality had to be clarified. The insights of the theory of special relativity confirmed the assumption of causality, but they made the meaning of the word "simultaneous" observer-dependent.[4] Consequently, the relativistic principle of causality says that the cause must precede its effect according to all inertial observers. This is equivalent to the statement that the cause and its effect are separated by a timelike interval, and the effect belongs to the future of its cause.

The key part here is in bold. Cause and effect are separated by a timelike interval. The separation has to be either time-like or space-like so this is equivalent to saying that there is no cause and effect separated by a space-like interval. I included more in the quote because the part in italics is the relativity of simultaneity again.

Outside the light cone is an imaginary zone where I can imagine causality exists just as you can imagine it does not.

Ok, I guess you are not joking. Time to put a stop to this nonsense. Outside the light cone is not an imaginary zone because we are not limited to a single place and time. As we move forward in time the events outside the light cone move into our past light cone and thus we know there is nothing imaginary about them. The same happens in reverse with events in the future light cone as they move out of it into the area outside the light cone. Thus if the events inside the light cone are real then so are the ones outside the light cone -- this follows by simple logic.

Regardless, if you admit that the the causes going outside the light cone are a product of your imagination then I would count that as conceding the point. In which case, there is no longer any need for me to address the issue in any more posts.

The measurements are not simultaneous and the timing of events is part of the experimental data so, when the observations on both ends of the experiment are compared, we can discover exactly the order in which the observations were made. When the experiments are repeated many times, they are found to be in violation of Bell’s inequality suggesting that the first entangled particle to be observed instantly fixes the quantum state of the other particle.

No you cannot. Any such determination of order is entirely relative to which inertial frame you look at them. This has already been demonstrated. Since this choice of inertial frame is arbitrary then so is any order determined for the events.

[bangstrom]

Looks to me like a tactic of wasting my time. But ok, I will do the first one, which is Wikipedia on causality.

In modern physics, the notion of causality had to be clarified. The insights of the theory of special relativity confirmed the assumption of causality, but they made the meaning of the word "simultaneous" observer-dependent.[4] Consequently, the relativistic principle of causality says that the cause must precede its effect according to all inertial observers. This is equivalent to the statement that the cause and its effect are separated by a timelike interval, and the effect belongs to the future of its cause.

The key part here is in bold. Cause and effect are separated by a timelike interval. The separation has to be either time-like or space-like so this is equivalent to saying that there is no cause and effect separated by a space-like interval. I included more in the quote because the part in italics is the relativity of simultaneity again.

I don't see where this article states that causality does not exist at space-like intervals. This is an assumption that goes beyond the wording.

Special relativity was formulated long before the experiments of Bell and Aspect that demonstrated non-local action at a distance where intervals are space-like (or possibly far to fast to be measured) and the same article makes no claim that special relativity has the last word on the topic.

If you read a few lines down, the same Wiki article says, “New subtleties must be taken into account when we investigate causality in quantum mechanics and relativistic quantum field theory in particular. In quantum field theory, causality is closely related to the principle of locality. However, the principle of locality is disputed: whether it strictly holds depends on the interpretation of quantum mechanics chosen, especially for experiments involving quantum entanglement that satisfy Bell's Theorem.”

This article from 2001 is a bit dated with its consideration of things like tachyons but it explains how special relativity and Minkowsky space are compatible with superluminal causality.

“Our analysis is motivated by some recent theoretical predictions of “superluminal” photon propagation [2, 3, 14]. We have shown that such effects are kinematically compatible with special relativity, because the latter requires only the existence of an in-variant speed, not necessarily a maximum one.”
https://arxiv.org/pdf/gr-qc/0107091.pdf

Ok, I guess you are not joking. Time to put a stop to this nonsense. Outside the light cone is not an imaginary zone because we are not limited to a single place and time. As we move forward in time the events outside the light cone move into our past light cone and thus we know there is nothing imaginary about them. The same happens in reverse with events in the future light cone as they move out of it into the area outside the light cone. Thus if the events inside the light cone are real then so are the ones outside the light cone -- this follows by simple logic.

This interpretation implies there is a direct connection between (a real) future, past, and present which may be correct and supported by experiments in QM but it is incompatible with the traditional interpretation of special relativity and this view does not exclude the possibility of causality in space-like intervals. It implies that the present has its cause in the future.

No you cannot. Any such determination of order is entirely relative to which inertial frame you look at them. This has already been demonstrated. Since this choice of inertial frame is arbitrary then so is any order determined for the events.

The determination of order is not relative when the experimental setup is analyzed from both perspectives. The timing order of a solar flare on the sun and a solar flare on Alpha Centauri can be determined from either end if we know the exact timing of each observation and the distance between the stars. The proper order of events can be calculated.

For example, if observer Alice observes her nearest particle first and finds it in the spin-up position she knows that observer Bob will find his particle in the spin down position. The same is true for Bob except that his observations are always anti-correlated to Alice’s observations.

Bell’s inequality is a statistical test to determine if the quantum status of entangled particles was present from the beginning, as with a coin that is either heads or tails, or if it was established at the time when the first particle was observed. Alice may think her observations were first so she determined the quantum state of the other particle and Bob may think his observations were first so he determined the quantum state of the second observation. In either case, the violation of Bell’s inequality suggests that the quantum state of the particles was determined at the time of the first observation. It doesn’t say which observer made the first observation and it doesn’t matter because both observers record the same violation of Bell’s inequality.

The actual timing of events can be determined by a later analysis of the times but it makes no difference which observer was first to cause the events because Bell’s inequality was violated for both observers.

[Faradave]

if ...Alice observes her nearest particle first and finds it in the spin-up position she knows that observer Bob will find his particle in the spin down position. The same is true for Bob except that his observations are always anti-correlated to Alice’s observations.

There's an important subtlety here that I believe you (as many) are missing. The total-spin-zero (TSZ) entanglement that you describe is a single shared state, not two separate states. Further (this is the subtle part), measuring one does not require any communication between them to determine the state of the other.

Here's a classical example adapted from the movie "Gravity". George Clooney and Sandra Bullock are astronauts in space bound by a long, mutual, umbilical tether (i.e. they are thus, "entangled"). Relative to the tether, they have opposite spins, a classical, total-spin-zero state. Even if they are very far separated, they maintain that state, relative to their entanglement connection.

1. (skip if it doesn't make sense) If they are translationally at rest (in the same inertial frame, ignoring spin), cutting their tether breaks entanglement simultaneously for each, because they share a "simultaneity" (they share the spatial coordinate of their inertial frame).

If (allowing slack in the tether) they happen to have a speed relative to each other, they have different inertial frames with different simultaneities. They'll argue as to which one was disentangled first, though this was clearly a single event to their mutual tether (state of entanglement). But they don't say it that way. Instead, each will argue that disentanglement occurred at a different time, according to their respective clocks. Who was disentangled "first" depends on whose clock you accept, as each sees the other's clock running slow. This is carefully avoided in nearly all discussions of entanglement (because it's confusing enough in the same inertial frame).

2. When the tether is cut, which way is Sandra spinning?

You can't say, because you didn't do the measurement! The only thing we know, is that she's opposite George. Say Sandra's clockwise, if the measurement is done from the front. Then George is counter-clockwise from his front. Similarly they're opposite if both measured from the back. Neither situation, required any "instantaneous" communication between them. What is required is careful prior orientation of the measurement. The spins are not absolute. They are observer dependent.

This applies equally for the orientation of (Stern-Gerlach or other) devices used to asses entangled properties. If an SG device on the north pole of the moon gives you a "spin up" reading for an electron, the same electron will be called "spin down" from an SG device on the moon's south pole (because the two SG devices are oriented opposite to each other at those poles).

P.S. While Sandra is equally beautiful from front or back (Oh, my!), those views are distinguishable. No such luck with electrons. The agreed scheme for orienting the measuring devices in space, is just as important as any agreed scheme for synchronizing clocks in time.

[bangstrom]

There's an important subtlety here that I believe you (as many) are missing. The total-spin-zero (TSZ) entanglement that you describe is a single shared state, not two separate states.

The shared state exists prior to observation but become two separate states after observation. The TSZ may be maintained after observation but can be disturbed by an outside force acting on one particle without altering the state of the other. This is not the case with entanglement where, if you mess with one particle, you mess with the other.

Further (this is the subtle part), measuring one does not require any communication between them to determine the state of the other.

The connection may not involve “communication” but it does require a non-local action at a distance which makes entanglement different from a classical connection such as a tether between astronauts where severing the connection causes no change.

With entanglement, the two particles act as if they are part of a single particle sharing a common Schroedinger wavefunction just as though they were side by side. Their location in space is indeterminate, not because their locations are unobserved, but because they have no location in space. It is as if the particles were were at both locations at once or rapidly swapping locations. In other words, their states are in “superposition.” This was the quantum absurdity that Schroedinger tried to dispel with his dead/alive cat experiment but Bell’s test found the Schroedinger theory of superposition alive contrary to Schroedinger’s expectation.

Here's a classical example adapted from the movie "Gravity". George Clooney and Sandra Bullock are astronauts in space bound by a long, mutual, umbilical tether (i.e. they are thus, "entangled"). Relative to the tether, they have opposite spins, a classical, total-spin-zero state. Even if they are very far separated, they maintain that state, relative to their entanglement connection.

1. (skip if it doesn't make sense) If they are translationally at rest (in the same inertial frame, ignoring spin), cutting their tether breaks entanglement simultaneously for each, because they share a "simultaneity" (they share the spatial coordinate of their inertial frame).

I don't see where this is an example of quantum entanglement or “action at a distance." The tether connection is strictly classical.

If (allowing slack in the tether) they happen to have a speed relative to each other, they have different inertial frames with different simultaneities. They'll argue as to which one was disentangled first, though this was clearly a single event to their mutual tether (state of entanglement). But they don't say it that way. Instead, each will argue that disentanglement occurred at a different time, according to their respective clocks. Who was disentangled "first" depends on whose clock you accept, as each sees the other's clock running slow. This is carefully avoided in nearly all discussions of entanglement (because it's confusing enough in the same inertial frame).

I can’t agree with this point and say there is a “first” and which one is first makes a difference. I will explain later.

2. When the tether is cut, which way is Sandra spinning?

You can't say, because you didn't do the measurement! The only thing we know, is that she's opposite George. Say Sandra's clockwise, if the measurement is done from the front. Then George is counter-clockwise from his front. Similarly they're opposite if both measured from the back. Neither situation, required any "instantaneous" communication between them. What is required is careful prior orientation of the measurement. The spins are not absolute. They are observer dependent.

The results are no longer observer dependent when you consider the total experimental setup or in the case of single observer where you have only one perspective. With two or more observers, you can examine both perspectives and see how they correspond.

This applies equally for the orientation of (Stern-Gerlach or other) devices used to asses entangled properties. If an SG device on the north pole of the moon gives you a "spin up" reading for an electron, the same electron will be called "spin down" from an SG device on the moon's south pole (because the two SG devices are oriented opposite to each other at those poles).

P.S. While Sandra is equally beautiful from front or back (Oh, my!), those views are distinguishable. No such luck with electrons. The agreed scheme for orienting the measuring devices in space, is just as important as any agreed scheme for synchronizing clocks in time.

In QM theory Sandra and George are in a state of superposition with both spinning in both directions like Schroedinger's dead/alive cat until observed.

The examples you give all involve situations where the anti-correlation of the two “particles” is set from the beginning and with two sets of dependent multiples. The Bell test is used to determine if the anti-correlation was established and maintained from the beginning or if it was established at the moment of first observation. The Bell test concludes that the quantum states in the case of entanglement are set at the instant of the first observation rather than from the beginning as with your examples.

The following is my understanding of your example but it does not demonstrate quantum entanglement. Alice is our first observer and if, she observes George first, she then knows Sandra is on the other end and, if George is rotating clockwise, Bob’s Sandra is rotating counter clockwise. She also knows George is male and Sandra is female. Essentially she knows a great deal about the other unobserved “particle.”

This example is different with quantum entanglement because quantum states come in a variety of independent combinations and we can only observe quantum states one at a time.

To make the example more quantum like, Alice has a 50/50 chance of observing George first and, if she does, Bob is certain to find Sandra on his end. If Bob is the first to make an observation of rotation, he has a 50/50 chance of observing Sandra with a clockwise rotation and, if he does, he knows Alice’s George is rotating counterclockwise from his perspective. If Bob observes the sex of the astronaut on his end he has a 50/50 chance of finding that Sandra is male and, if so, that means Alice’s George is female. This is where the firstist observation is the importantist.

Either Alice or Bob can make all of the first observations or they can both make observations without knowing which was first but the results are the same. If the quantum states are anti-correlated from the beginning, then observers automatically know the condition of the opposite pair by just observing a single particle. This is the sort of results one can expect if the quantum identities were established from the start and it equates to the Bell test results of +/- 2.0.

There is a quantum alternative where the entangled particles are in a state of superposition and the first observation of one particle sets the quantum state of the other particle. I don’t quite follow the statistics but some tests of Bell’s inequality are like the experiment where a third polarizing filter placed between two polarizing filters that completely block the light will let light pass. This equates to the Bell test where the results are an unexpected +/- 2.8.

There is another test of Bell’s inequality where three quantum states are observed and the results are again an unexpected +/- 2.8 indicating that the quantum states were set at the instant of the first observation rather than present from the beginning.

This article explains the Venn diagram and the sort of results one should expect from a classical experiment then it mentions how quantum results are different and counter intuitive. http://www.techlib.com/science/bells_inequality.htm
“In quantum mechanical systems where particles are "entangled" the number of items in the solid orange and blue areas can seem to exceed the number of items in all four colored bins. That's just crazy talk.”

The larger than expected blue and orange areas represent the greater +/- 2.8 results of Bells test indicating that the quantum states were established at the instant of first observation rather than present from the start.

[Faradave]

Much of what you write is spot on. You've clearly done your reading. For the record, I'm in full agreement with Bell's theorem as he brilliantly demonstrated it.

The shared state exists prior to observation but become two separate states after observation. The TSZ may be maintained after observation but can be disturbed by an outside force acting on one particle without altering the state of the other. This is not the case with entanglement where, if you mess with one particle, you mess with the other.

This is critical to understanding (or at least specifically identifies where we disagree). If, in fact, rotating one particle here actually caused an distant entangled particle to simultaneously rotate, that would indeed be superluminal "spooky action at a distance". But that's not the case.


First, it's very difficult to manipulate a fundamental particle without doing the equivalent of making a measurement, thus breaking entanglement. This is one of the reasons single electrons are never sent through an SG device to assess a spin component (typically silver atoms are used).

Second, rotating a particle simply changes the spin component being assessed (say from a Left-Right to a Front-Back assessment). Assuming this can be accomplished without breaking entanglement, it would be like turning Sandra while still tethered to distant George. No matter how you turn Sandra, you are not doing anything to George. They maintain their total-spin-zero (TSZ) state, with respect to their umbilical tether, as long as that connection is unbroken.

The connection may not involve “communication” but it does require a non-local action at a distance which makes entanglement different from a classical connection such as a tether between astronauts where severing the connection causes no change.

"action" (i.e. interaction) involves transmission of mass, energy or information. "Non-local action at a distance" is at least as untenable as mere communication. Neither may violate universal speed limit c in any observable way. (Literature will allow "virtual" particles such violation, within the bounds of uncertainty, or the unobservable confines of a Feynman diagram. I intend to dispel all that, but not here.)

ER=EPR equates the entanglement connection to a spacelike (thus, specifically "non-traversable" by mass, energy or information) wormhole. One consequence is that entanglement can only be broken at the particles, nowhere in between. Being spacelike, to access the "tether" connecting entangled particles, you'd have to go back in time!

I ... say there is a "first" [observer] and which one is first makes a difference.

Relativity of simultaneity, as expressed by Einstein's "simultaneous" lightning bolts, says that "first" is relative for spacelike (non-causal) events. For causal events, located on or within a lightcone, different inertial observers will argue the spatial and temporal separation of events but all will agree that cause precedes effect.

The results are no longer observer dependent when you consider the total experimental setup or in the case of single observer where you have only one perspective. With two or more observers, you can examine both perspectives and see how they correspond.

Be careful! "when you consider the total experimental setup" itself requires an observer perspective (such as a center-of-mass, or center-of-momentum frame). With two observers, you'd have to declare if they share an inertial frame or not. It does indeed make a difference. But, I probably shouldn't have brought up the subject of entangled particles in motion.

[Faradave]

Euclidean, interval-time coordinates (as an alternative to non-Euclidean spacetime) depict the 4D continuum divided differently.

Left: Minkowski spacetime typically divides the continuum with a lightlike interval of slope 1.
Right: With interval-time coordinates, regions are divided by the interval coordinate, having slope 0.

A natural consequence of this is a curved-space, radial-time model, as shown in this video.



In that model, spacelike V_x represents a superluminal velocity, unattainable because it violates the fundamental unidirectionality of time. Yet it can still serve as a mutual reference (like a tether) about which distant particles can co-relate a shared property, such as total-spin-zero.

Each blue arc represents a spatial simultaneity from which the tangent separates allowable trajectories (at & above) from non-traversable ones below. (t1=now, t2=a future moment)

Thus interval-time coordinates imply a speed limit in two ways:
By magnitude - c is an absolute speed limit because zero interval separation is an absolute proximity limit.
By slope - c is the limit of speed because tangent is the limit of slope, without crossing the arc (and going backward in time).