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Is it possible to use Quantam entanglement to study event horizon

  1. Mar 31, 2014 #1
    I have a doubt/question/idea what ever it may be some thing like this

    Theoretically is it possible if we place one of twin electrons(Quantum entanglement)into event horizon of Black hole and observe the second one on earth, so that what is happening in Black holes? i.e how electron's inside event horizon have physical properties such as position, momentum, spin, polarisation, etc are correlated with first one on earth?
  2. jcsd
  3. Mar 31, 2014 #2


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    It is not possible. This is a variant of the often-asked question, "can we use quantum entanglement to send a faster-than-light message?" and the answer is no. Search around this forum and you'll find some explanations of why not.
  4. Mar 31, 2014 #3


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    But suppose an experimental probe was orbiting the black hole; it could create entangled photons, and ship one over the event horizon, and study the ones kept. This does not seem to involve any FTL transfer of information.

    Why wouldn't this provide some useful information?
  5. Mar 31, 2014 #4


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    Indeed, in this way by measuring spin of the particle on Earth, you may determine the spin of the corresponding twin-particle inside the event horizon. But so what? In this way you cannot learn anyhing interesting. In particular, you cannot learn anything about the other black-hole degrees of freedom which are not directly related to your twin particle.
  6. Mar 31, 2014 #5


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    Why don't you try what Nugatory suggested, UltrafastPED? Just type "entangled black hole" into the Search box at the top of the page. You'll find many previous threads that answer the question for you.
  7. Mar 31, 2014 #6
    For the same reason that the standard EPR arrangment in flat space can't be used to send useful information.
  8. Mar 31, 2014 #7
    The "spooky action at a distance" produces interesting statistical results. However, you can't tell that you have those interesting statistics until you compare what has been measured at the two distant points.

    If you have a two streams of entangled particles, one measured at location A, the other at B, at first glance neither A nor B see anything beyond a random results. Only when A and B exchange information about their measurements that patterns emerge.

    So if A is above the event horizon and B is below, Alice at A can sent Bob at B her results and B can then read any message that Alice may have transmitted but since Bob cannot transmit anything to Alice, she will remain in the dark about everything about Bob's measurements.
  9. Apr 1, 2014 #8


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    If this is such a common thread, perhaps it should be in the FAQ.
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