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Indirectly measure if particle spin is in superstate or not?

  1. Feb 20, 2015 #1
    Hey I'm curious if it would be possible to measure if a particle's spin is in a superstate similar to how the double slit experiment can show whether or not an electron's location is in a superstate. Wouldn't such a machine allow for FTL communications, since if we measure one of two entangled particles spin state, we force the other particle's superstate to collapse.
  2. jcsd
  3. Feb 20, 2015 #2
    No, as the spin state has a random result when measurement is made.
  4. Feb 21, 2015 #3


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    Just out of curiosity: What is a "superstate"?
  5. Feb 23, 2015 #4
    haha, sorry, I meant superposition (I though super position only referred to a particle's location state). Also, if anyone's wondering, communication is impossible between two entangled particles [A,B] because the entanglement is the only thing the two particle's have in common, since we can't know the state of the particle A before we measure it, we have no way of checking if someone else measured particle B, making it impossible to determine not only what the state was, but even if a state change happened!

    https://en.wikipedia.org/wiki/No-communication_theorem goes into it a bit more, showing that according to the rules of quantum mechanics, none of the properties of particle A that we can glean without measuring are changed in anyway when we measure the state of particle B.
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