Imagine that i had two entangled photons . I kept a photon beside me without knowing its spin and sent the other photon inside a black hole . Then i measure the spin of the photon beside me . Is is certain that the photon inside the black hole will have opposite spin as the one beside me?

  • $\begingroup$ Hah! Maybe we will figure it out when one would actually come up with a decent explanation of why black holes even exist and what they are. But it is a cool idea to try to monitor a member of an entangled pair of electrons while the other one is in a black hole; hence, use it as a probe... Me like it =P $\endgroup$
    – MsTais
    Jan 5, 2018 at 23:42
  • $\begingroup$ My suggestion would be to specify which model of a black hole you would like to consider, if you expect more exact answer. $\endgroup$
    – MsTais
    Jan 5, 2018 at 23:44
  • 2
    $\begingroup$ From your position the second photon will not reach the event horizon at any time in your future. So there is never a time, in your reference frame, when it's inside. $\endgroup$ Jan 6, 2018 at 0:43
  • $\begingroup$ @StephenG But when black holes grow the event horizon grows with it, right? $\endgroup$
    – OTH
    Jan 6, 2018 at 7:08


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