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Quantum entanglement to communicate from inside black holes

  1. Jun 27, 2013 #1
    I have just joined this forum as I am curious to discover from experts if my idea is physically possible. Once you pass the event horizon of a black hole nothing can escape as the space time "fabric" is moving into the black hole at equal to or greater than the speed of light.
    But I hear from quantum physics that two quantum entangled particles can instantly communicate potentially from across the universe from one another. Say I entangle two particles, keep and observe one, and send the other one into the black hole beyond the horizon. Could I theoretically communicate with that black hole particle once it has passed the horizon?
    (I am assuming the black hole is super massive so the spaghettification does not destroy the particles before it can enter the event horizon.)
  2. jcsd
  3. Jun 28, 2013 #2
    They can't communicate information, that doesn't transfer instantly.

    You don't think that the particle crossing the event horizon is going to destroy it? What is it that you think you're going to be talking to once it's in there?
  4. Jun 28, 2013 #3


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    The event horizon of a black hole marks the point where an entering particle is causally disconnected from the rest of the universe - forever.
  5. Jun 28, 2013 #4
    I don't.
  6. Jun 28, 2013 #5
    Is this referring to Susskind's side of the black hole wars? Is he going to be communicating with some representation of the particle's information smeared out over the surface? Please do elaborate.
  7. Jun 29, 2013 #6
    no,no..if anything Susskind says, via black hole complementarity, that two 'copies' of the information exist....sort of....

    I was trying to say that 'causally disconnected' [The GR viewpoint expressed by Chronos.] is not the same as 'destroyed'. [edit:But I don't know exactly what 'causally disconnected' means, either...is that forever??}

    Anyway, neither side thinks anything is necessarily 'destroyed' immediately in free fall through a BH event horizon.
  8. Jun 29, 2013 #7


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    Black holes are not eternal, so will eventually return all the energy it captured via hawking radiation until it loses so much mass it can no longer remain a black hole. At that point it will fall apart in a dazzling blaze of ... er, poof of embarrassment. It takes an incomprehensible amount of time for this to happen - many to the power of many times the current age of the universe. The universe must first cool to a point lower than the radiating temperature of a black hole [which is very tiny] before a black hole can even begin to lose mass via hawking radiation.
  9. Jun 29, 2013 #8
    I used to think that too....but am now not so sure...Apparently black bodies radiate even when the surrounding temperatures are higher??....So it seems when Hawking radiation exceeds mass/energy absorbed by a BH for an extended period, really extended period, it can go in a 'poof of embrarrassment'. That's why, I think, it is said Hawking evaporation can't be detected..it IS there, but much too weak...

    [great description by the way!!] I never pursued the details much since I expect to be loooong gone....
  10. Jun 30, 2013 #9
    if the blackbody temp is less than the surrounding temperature the BH will absorb the surounding energy. The post by George Jones in this thread covers that in regards to Hawking radiation. There4 are other processes involved though.

  11. Jul 1, 2013 #10
    I retract the "I am not so sure" part of my prior post...in fact my wording is contradictory ...... Black bodies DO radiate Hawking radiation at all times as they are near perfect black bodies as I posted above. Chronos' description is also correct....they also absorb CMBR type thermal radiation....

    Roger Penrose describes this exact process on page 839, 30.8, of THE ROAD TO REALITY and points out that Hawking described the process in 1974:

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