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Black hole matter/antimatter

  1. Sep 11, 2008 #1
    Is matter going into a black hole the same as antimatter leaving one?

    This has confused me for a while...

    Thanks,
    Jamie
     
  2. jcsd
  3. Sep 11, 2008 #2

    George Jones

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    No.

    Matter and antimatter falling into a black hole increase the mass of the black hole. Matter and antimatter "leaving" (Hawking radiation) a black hole decrease the mass of the black hole.
     
  4. Sep 11, 2008 #3
    But wouldn't the antimatter and matter anihilate one another inside the black hole?
     
  5. Sep 11, 2008 #4

    George Jones

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    My point was that since matter falling into a black hole increases the black hole's mass and antimatter leaving a black hole decreases a black hole's mass, these two processes are not the same
    Only if their worldlines intersect inside the black hole. Even if this happens, the mass of black hole remains unchanged from the mass just "before" the annihilation event.
     
  6. Sep 11, 2008 #5
    Is that due to the conservation of energy and mass?
     
  7. Sep 11, 2008 #6

    George Jones

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    Yes, this is because of (local) conservation of mass/energy.
     
  8. Sep 11, 2008 #7

    wolram

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    What is this antimatter?
     
  9. Sep 11, 2008 #8

    George Jones

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    For every particle of matter, there is a corresponding particle of antimatter. The (additive) quantum numbers of an anitparticle have values that ere the negatives of the values of the quantum number for the corresponding particle.

    For example, an electron has negative electric charge, and a positron (anitmatter electron) has positive electric charge. If a particle and corresponding antiparticle collide, they annihilate each other, releasing energy.
     
  10. Sep 11, 2008 #9

    mheslep

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    Tangents, if you are inclined:
    Assuming the electron and positron are the same thing(? same mass, etc) differing only in charge:
    1. Why don't an electron and positron settle into quantum mechanical orbitals about each other similar to the traditional electron and nucleus?
    2. If an high energy electron can in fact be made to collide with a (proton based) nucleus, why does it not 'annihilate' some 1/1800 th of the much larger proton?
     
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