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FTL, causality, QE - some questions

  1. Jun 17, 2012 #1
    There are numerous posts on (attempting) FLT information via QE and whether causality is violated.

    I believe that there are definite answers to them and are buried (out there somewhere) in the gazillion posts/replies in the forum.

    FTL = faster than light, QE = quantum entanglement

    I hoping this to be a quick question with short answers and some of them will turn out to be definitive.

    I am looking to answers such as:

    - Does (mass/energy-less) FTL information violate casualty/relativity? as long as there is no mass/energy involved
    - Is information transferred in QE? (even if you have to compare via co-incidence counter as speed of light)
    - Is there such a thing as mass-less information transfer? i.e. Can you really transfer information without involving (exchange of) mass-energy?

    Which is true? or if partially true ...please correct

    QE does transfer information (FTL); however this transfer of information does not violate causality/relativity


    QE does not transfer information and information can never be transferred FTL because it would violate causality (and/or) relativity.

    Side note: For (supposed) information transfer via QE we can use the entangled photons experiments (such as single particle, double slit experiment with signal and idler or mach zehnder).

    Here we do which-way (or not) on one of the entangled photons and then notice the effect on the other that is separate by vast distances between Alice and Bob.
    Last edited: Jun 17, 2012
  2. jcsd
  3. Jun 17, 2012 #2


    Staff: Mentor


    Is that short enough?
  4. Jun 17, 2012 #3
    thanks DaleSpam. That answers one of the questions, though the rest become hypothetical...
    Last edited: Jun 17, 2012
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