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Black hole photon emission

  1. Sep 8, 2012 #1

    I've been reading through Stephen Hawking's 'A Brief History of Time' and I have reached a section about how, contrary to popular belief, Black Hole's are not necessarily black since they emit photons outside the event horizon.

    I am wondering how they emit photons. Does it have to do with particle and antiparticle annihilation?

  2. jcsd
  3. Sep 8, 2012 #2
    Sort of. The usual explanation of 'hawking radiation' (as it is called) makes use of particle/anti-particle annihilation in the context of the quantum foam near the event horizon of the black hole, this is detailed pretty well on the wikipedia page on black holes: http://en.wikipedia.org/wiki/Hawking_radiation

    I've heard however that the actual process is much more complicated, but as of yet there isn't a better way to non-mathematically describe it.

    Edit: I actually just read through the math on the wiki page for the first time and it does a pretty decent job.
    Last edited: Sep 8, 2012
  4. Sep 8, 2012 #3


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    It makes sense to have a look at Hawking's paper which can be found on the internet. Hawking is talking about particle-antiparticle pairs but (the math of) the process is more bizarre than that. There are no particle-antiparticle pairs and no tunneling through the event horizon or something like that. Nothing haoppens "at the horizon"; you will not see anything special there
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