Why does action-at-a-distance have to be "spooky"?

Discussion in 'Physics & Math' started by cosmictotem, Oct 13, 2016.

  1. cosmictotem Registered Senior Member

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    I was just watching a doc showing how Bell's equation proved Bohr to be correct about the states of quantum particles before they are observed.

    And the conclusion seems to be that it's difficult if not impossible to explain in logical terms.

    But I'm not sure exactly why that is. I don't know if I'm just not understanding how unintuitive quantum theory is or if I've found a sensible way to explain it to myself.

    The way I try to explain away the "magic" of the entanglement problem for myself is this:

    Suppose we have two observers. One human and, let's say, one alien, possibly even from another dimension.

    Now say both the human and this alien process colors differently. And say, both the human and the alien are looking at a pair of the same two stars. Star A and Star B.

    To the human, the color of Star A looks blue and the color of Star B looks red.

    This is because our perceptions, by their nature, process the color spectrum in a certain way.

    But to the alien, Star A looks yellow and Star B looks, say, green.

    This is because due to the nature of the alien's perceptions, they process the color spectrum in a unique way to humans.

    So because of the nature of the elements composing these two stars and the nature of the two different observers perceiving them, a star with the nature of Star A is always going to look blue and a star with the nature of Star B is always going to look red, to the human eye.

    Before we knew these two stars existed we didn't know what color they would be. But once we observed the first star, Star A, by how the color spectrum works with our unique perceptions, the color of the other star, Star B, falls into line because star colors conform to the color spectrum that acts upon our perceptions and the way they process light from elements.

    In other words, if "star" conforms to the definition of an existent for human perceptions, then the state of all stars must automatically conform to the color spectrum compatible with human perceptions.

    And the same thing could be said for the alien. The alien sees different colors when they look at the same stars because they process the color spectrum differently or the physics by which they process existents is different.

    So once you observe the color of Star A, the physical laws that determine how humans process the color of stars automatically gets applied to the other star, Star B as the color red.

    In other words, the physics is always there (Star A and Star B share the same physics, no matter whose physics it is) but the state depends on the presence of the observer and the physics compatible to the nature of that observer.

    So in essence, contrary to Bohr, it's really not "spooky" or unexplainable by logic.

    Does this make sense or is the problem stranger than I realize?
     
    Last edited: Oct 13, 2016
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  3. danshawen Valued Senior Member

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    If both the alien and us use the same instrument (a spectrograph) to measure color, then there will be no ambiguity in the way it is measured, as opposed to an individualized form of perception.

    As for "spooky" action at a distance, it is only spooky to us because we don't yet know enough about quantum entanglement to connect one quantum spin flip to another, like a row of tumbling dominoes.
     
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  5. billvon Valued Senior Member

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    Well first of all that's just perception. I could say "in my language 'red' is really 'blue' - so that star is blue" and be just as right as the alien.
    Second, that red star might look very different if you are approaching it at a significant fraction of the speed of light; it might well look blue to you then. (It wouldn't really BE blue, it would just be blue-shifted so you see blue light from the star.)

    But that's somewhat beside the point. What you call a phenomenon has little to do with the actual physics of it.
    No. Both creatures could measure the energy of the photons coming from the star and relate them to universal constants (like, say, the Planck wavelength) and if done correctly their observations would be identical.

    That is quite different than the quantum collapse of entangled particles. ANYONE, alien or not, who observes such a state will cause a collapse of both particles no matter how distant they are - and that (per classical physics) should not happen.
     
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  7. cosmictotem Registered Senior Member

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    Why is that? Are not the physics the same for both particles?
     
  8. cosmictotem Registered Senior Member

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    Okay, then what about because they share the same physics that conform to our interpretation of states? Is not the physical laws that govern the expression of existents already in place?
     
  9. billvon Valued Senior Member

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    That's spooky action for you. It _seems_ not to be possible that such a change could propagate faster than the speed of light, or that observing one could affect the other at all. It turns out that sending information via selective observation is still impossible, though.
     
  10. cosmictotem Registered Senior Member

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    Ah, that's what I was missing. ...The physicists do not just observe one particle, they change its state and that causes the state of another particle to change?

    As I attempted to explain, I think I could understand how observing one particle could seem like it causes another particle to conform to an observation. But I guess it would be harder to explain how altering the initial state of one particle (if physicists indeed do that) could change the state of another particle instantaneously.

    i guess I'm unclear exactly what "observing" entails because I keep coming back to trying to explain it. Are scientists only just observing the state or are they changing the state of a particle from one state to another?
     
  11. DaveC426913 Valued Senior Member

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    Two particles A and B are emitted from a source and travel in opposite directions.
    They travel far enough apart that they can no longer interact classically (over the course of our test).

    We measure a binary property of one (say, spin which could be up or down), and this will cause the other one to have the opposite spin.

    Here is the kicker: they did not have that spin when they were interacting, and they did not carry any information about their eventual spin with them. In fact, Bell's Hidden Variables theorem shows that they cannot have any "hidden" properties that they might have taken with them from the initial interaction.

    So, how can a particle - unable to communicate, and not carrying any information with it - cause the other fall into a specific state?
     
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  12. cosmictotem Registered Senior Member

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    Isn't it obvious that, for the particles we observe, by observing them we are interacting with them in some way and changing them?

    Btw, if we measure particle A, how do we know the state of B if we don't measure it? And if we measure B, isn't that interacting with it?

    It just seems to me the secret to the riddle is by observing particles that exist in the same universe as ourselves, we are applying our physics on them when we observe them.

    In other words, they conform to the physics in the universe of the observer. That doesn't seem weird at all to me.
     
    Last edited: Oct 14, 2016
  13. DaveC426913 Valued Senior Member

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    The key word above is cause. i.e. one makes a change in the other.

    In your example of two observers, one observer has no effect on the other observer, so it does not matter if they are separated and can't communicate with each other. They are only interacting individually with an intermediate object (the star).

    What would be crazy is to have one obsever at one end of the galaxy read the spin on a photon from the star and have the other observer, at the other end of galaxy capture the corresponding photon and know what its spin is going to be. How did photon B know what photon A decided to do?
     
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  14. DaveC426913 Valued Senior Member

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    The crux is: how does particle B know what change happened to particle A, since they can't communicate?
     
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  15. cosmictotem Registered Senior Member

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    It doesn't. My point is, if we change A from no state to a state by observing it, the answer is we are the ones changing B because, no matter where B is in our universe, if we were to check it, we would be checking it under the same physical laws of our universe.

    I mean, think about it. What is the one thing that the universe might have in common from one end to the other? Physics. But who interprets physics? The observer.

    So we are changing particle B by our mere existence and observing of particle A. B is changing because we are here to change it by looking at the universe from our own perspective.

    That doesn't seem weird to me but maybe I'm still not understanding the entanglement experiment.
     
  16. danshawen Valued Senior Member

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    I'm going to try much harder to avoid any wacky or pseudoscience answers to such questions here for once and just provide you with what Einstein himself had to say on the subject. Have a look at this:

    https://www.technologyreview.com/s/...ion-at-a-distance-paradox-older-than-thought/

    and IN PARTICULAR, this is what Einstein had to say about quantum entangled particles:

    "Entangled particles can become widely separated in space. But even so, the mathematics implies that a measurement on one immediately influences the other, regardless of the distance between them.

    Einstein also pointed out that according to special relativity, this was impossible and therefore, quantum mechanics must be wrong, or at least INCOMPLETE. Einstein famously called it spooky action at a distance."

    What sort of incompleteness do you think Einstein was talking about? That's right, the kind of incompleteness that was the entire career of Einstein's friend Kurt Gödel. What is it about the mathematical reasoning used in Special Relativity that is rendered incomplete by a description of quantum entanglement? It's the part where Einstein's mentor Minkowski famously said that IN SPECIAL RELATIVITY, NO TWO EVENTS ARE EVER SIMULTANEOUS. Since entanglement spin flips of electrons and photons are known to occur faster than light can traverse the distance between them, the description of bulk propagation of energy at speeds less than or equal to the speed of light is what is "incomplete". This incompleteness can only be overcome by an extension of the theory which includes quantum entanglement spin flips at velocities which exceed c, and do not obey Minkowski's edict that no two events in spacetime are ever simultaneous.

    Get it?
     
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  17. DaveC426913 Valued Senior Member

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    Sorry. The final piece of the puzzle is that the two states (in the case of spin) will be ALWAYS be opposite. It might be A:up, B:down, or A:down, B:up. And no way of knowing which it will be.

    So, A has no spin state, and when it is measured, it turns out to be up.
    If B is never measured, we'll never know, but if it is, it WILL be down.

    It is not any arbitrary change. The changes - despite being light years apart- and with no hidden properties being carried with - are in sync.

    B did not choose up or down until A was measured. And then B instantly became the opposite.
     
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  18. PhysBang Valued Senior Member

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    No. Entirely different sort of incompleteness.

    Not what either said. They merely said that the simultaneity of events, given a decent operational definition, depends on the choice of the system of coordinates.

    So much for avoiding pseudoscience.
     
  19. PhysBang Valued Senior Member

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    cosmictotem is actually offering up a plausible interpretation of quantum mechanics. States do not know things, people know things. Entanglement may be part of a logical requirement of physics. There is a rich field of quantum logic.
     
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  20. cosmictotem Registered Senior Member

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    Ok thank you. I do get that part.

    But what if the propagation of physical laws (physics) themselves is never two events but one? And what seems like instantaneous action is just us seeing the physical laws that are already laid out between the two particle working on both particles?

    In other words, to recognize the physical laws that say one particle at one end of the universe should have an up spin, is the same event as another particle at the other end of the universe having a down spin.
     
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  21. cosmictotem Registered Senior Member

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    Correction: In my opening post, I erroneously attributed the description of "spooky" to Bohr. He was only defending what Einstein described as spooky.
     
  22. cosmictotem Registered Senior Member

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    Suppose there are two physics occurring in the universe.

    Suppose there is a super-physics of the universe that says particle A and particle B are already opposites but have undefined states.

    And then suppose there is a second local-physics compatible to human perceptions and our nature.

    The super-physics of the universe says particle A and particle B are opposites but says nothing about what kind of opposites they will be or in what state that will manifest.

    But the local, human physics, when applied to the particles through our interaction with one or both, creates states measurable and perceptible to human perceptions.

    So the super-physics of the universe is sort of an undefined physics which says only the basics, that things will be either this or that, opposite or same, slightly different or more different but it says nothing about HOW they will be those things.

    And local-physics (the physics humans understand) lays on top of super-physics, coloring things, giving them specific states we can measure and see, etc...

    Local-physics is therefore relative to the observer and super-physics is not.
     
    Last edited: Oct 14, 2016
  23. danshawen Valued Senior Member

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    And what if Minkowski's other edict, that space and time are inseparable, was also mistaken because one of them does not really exist, and the one that doesn't exist is space, not time. They are one in the same, and do not require complex numbers just to rig it so that time has an arrow. Both time and inertia have an arrow that is related to the direction of propagation, or in the case of entanglement, direction of spin.

    Photons only carry linear inertia in a single direction (the one of propagation), but bound energy may have inertia in all directions. Galileo and Newton never provided that detail explicitly. It is also easy to forget that if there is a rest frame with respect to linear propagation, then there must be an equivalent invariant state for quantum spin or entanglement as well. Zero quantum spin is the Higgs mechanism, finally verified, but not immediately understood, in 2012. That is how inertia crosses to/from linear/spin or entanglement mode. The Higgs field is entangled everywhere. It makes large gravitating objects round, provides for 2% of inertia of atomic structure, and even works at the exact geometric centers of black holes. It may take forever to fall into a black hole, but it doesn't take forever to be affected by the gravity of one. Quantum entanglement is the reason this is the case.

    How much energy went into producing the first ever detected gravity wave? One solar mas out of 50. Does that sound like a familiar percentage? It wasn't e=mc^2, was it? Energy, bound or not, is neither created nor destroyed when black holes merge, but evidently about 2% of it from its very core goes into making gravity waves.
     
    Last edited: Oct 14, 2016
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