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Black Hole Event Horizon exists?

  1. Mar 1, 2015 #1

    ChrisVer

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    Is there a physical boundary that is the event horizon? Or is there not?
    The reason I'm asking is because texts say that the event horizon that appears in Schwarzchild's metric is a result of the coordinate choice, and it disappears by choosing some other coordinates.
     
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  3. Mar 1, 2015 #2

    A.T.

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    I think what they say is that the singularity at the EH exists only in some coordinates.
     
  4. Mar 1, 2015 #3

    Nugatory

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    The singularity at the horizon is a result of coordinate choice (you can make it go away by choosing, for example, Kruskal coordinates) but the physical significance of the event horizon is not. The event horizon is a light-like surface, and "physical boundary" is not an especially natural term for describing it, but it is a well-defined surface in the Schwarzchild spacetime as long as you use coordinates that aren't singular there.
     
  5. Mar 1, 2015 #4

    George Jones

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    I have never encountered a text that says this.
     
  6. Mar 1, 2015 #5

    ChrisVer

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    That's a coordinate singularity. It exists due to the choice of coordinates, and can be resolved by a more appropriate choice of coords.
     
  7. Mar 1, 2015 #6

    Ibix

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    At risk of putting words in George's mouth, I think he's pointing out that a coordinate choice doesn't remove the event horizon, which is a co-ordinate independent surface. You can remove the coordinate singularity at the event horizon by careful choice of coordinates, but the horizon remains.
     
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