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Generalizing entanglement: Aren't all quantum events superluminal?

  1. May 29, 2009 #1
    Generalizing entanglement: Aren't all quantum "events" superluminal?

    If as it seems, the speed of the collapsing wave front of entangled particles occurs at a superluminal velocity, what is special about entangled particles? It follows that all quantum changes occur at superluminal rates, e.g. the orbital shifts of an electron that absorbs or emits a photon in the process. If this orbital shift is not fast with respect to the speed of light, the peppy little photon will be stretched out across space and would then itself have to snap into a coherent, respectable photon at superluminal speeds. Either way, something is happening at trans light speed. Similarly, regarding a photon that passes through a diffraction grating, it seems one explanation of the strange finding that even single photons create a diffraction pattern in the two slit diffraction experiment is that the un-collapsed photon is such a large wavicle--wave packet—that it interferes with itself. When this relatively large photonic probability waveform strikes the sensor at the back and causes an electronic discharge, doesn't the collapse of its wave function and the subsequent transfer of energy also have to occur at a rate which is “fast” relative to light speed or part of the photon will have had time to bounce off the sensor and would be racing back towards the grating once again stretching it out so that it must be “sucked in” at superluminal speeds or some part of it will never actually “get in?” Either way superluminal velocities are involved, implying this is the rule not the exception. My regrets to Professor Einstein.
  2. jcsd
  3. May 29, 2009 #2


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    Re: Generalizing entanglement: Aren't all quantum "events" superluminal?

    I think this is pretty much the case (as you describe). When a photon is detected "here", it no longer has the possiblity of being detected "there". So the collapse changes a probability amplitude everywhere the packet existed (i.e. to 1 or to 0).

    But is it physical? And is it superluminal? There are interpretations in which a superluminal action is not required to explain the results.
  4. May 31, 2009 #3
    Re: Generalizing entanglement: Aren't all quantum "events" superluminal?

    There is--actually was--a thread entitled something like "Feynman's double slit experiment" where passions ran so high the thread was locked down. At least one poster categorically denied that the statement "interference patterns continue to appear even when there is only one photon at a time going through the grating" or "disappear when path is determined" have any validity and produced a number of references to prove it. Furthermore, it seems like Dirac's statement that photons cannot interact with other photons was premature and inaccurate in everyone's judgment. Bell's inequality while possibly being demonstrable proves nothing of consequence and where quantum mechanical superluminal events might occur, if they do, no information is transferred so there is no worry about violating special relativity. Do you concur with these general statement which basically boil down to all the really cool stuff about quantum mechanics is either wishful thinking, sensationalism, mysticism or just sloppy experimental technique. I wonder.
  5. Jun 1, 2009 #4
    Re: Generalizing entanglement: Aren't all quantum "events" superluminal?

    Sounds crank.

    They can interact, but the interaction is quite weak.

    Depends on what you worry about. Observable effects will be Lorentz invariant. If you worry about what really happens, you need superluminal effects for explanation.
  6. Jun 1, 2009 #5
    Re: Generalizing entanglement: Aren't all quantum "events" superluminal?

    Much appreciated. Thanks.
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