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Black holes and photons ?

  1. Jun 26, 2010 #1
    This may be a dumb ? , but what would happen if two black holes were coming together and when they were coming together we got a photon extremely close to their event horizons , and when the came together the photon was right on the overlap of their event horizons which way would the photon go , or maybe we could shoot electrons an positrons right in between the black holes and get the emitted photons right on the overlap of their event horizons ,
    I realize this is a vary tricky scenario if not impossible scenario but i would like some responses , I mean the forces couldn't just cancel because we cant stop or slow down a photon , would the photon be red-shifted or blue shifted .
  2. jcsd
  3. Jun 26, 2010 #2


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    Photon is delocolized and quantum, inherently. If it happens to be heading towards one of the black holes, it will keep going towards it. If it tried to squeeze just between them, but doesn't quite make it, it will go both ways, being in superposition of being absorbed by one black hole and the other. Classical outcome will be 50/50 of it going one way or the other.
  4. Jun 26, 2010 #3
    how can it go both ways
  5. Jun 26, 2010 #4


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    Quantum physics. Superposition, basically.
  6. Jun 26, 2010 #5
    good question

    may I suggest something?

    while it is way way unlikely that the photon will go exactly between the two without first being dragged in one direction or the other during the initial approach (toward the black holes), I think that in the circumstance of the photons that could make it to the middle, would simple have their wave properties stretched and disrupted. Assuming it goes throught he middle on a trajectory that would take it away from the black hole's.

    it would look like this- If I shoot a few photons in this "in between" trajectory, I think the light wave property of the photon, would be stretched otu between the two blackholes. This would result (obviously) in the permanent changing of colour, if not complete dispersal of the wave itself due to gravametric tidal forces (which, by the way, I am also not accounting for the gravity currents (like water currents) the gravity of two obviously very moving blackhole's (the speed of rotation for these two bodies would cause this photon to more likely fall into either holeupon closer approach- and if the black holes werent moving too much to begin with, they will have tidal forces exchanged between them in their approach)

    I would for sure love to learn more about why the other guy though they would split into two photons in superposition though.

    Also, I should mention that I haven't mentioned the possible variable of hawking radiation. In the end though, while possible, I think it very unlikely this photon would get through without being stretched into a different colour.
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