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Black hole confusion

  1. Nov 13, 2009 #1


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    In a recent thread I erroneously claimed an obsever falling into a black hole would experience infinite blue shift at the event horizon. After a few beat downs I realized my error, but, was curious how I arrived at that flawed conclusion. After a bit of research, I blame it all on Karen Masters . . .

    http://curious.astro.cornell.edu/question.php?number=348 [Broken]
    “... Eventually at the event horizon there is an infinite shift - so the light has an infinite amount of energy, but zero wavelength. ...”

    but then I realized she was talking about a stationary observer at the event horizon. An infalling observer would have a different perspective as noted by

    “... Near the singularity, the observer's view is aberrated by the diverging tidal force into a horizontal plane. The view in the horizontal plane is highly blueshifted, but all directions other than horizontal appear highly redshifted. ...”

    Physics is hard, so I resort to videos


    “ ... Click on the image at left (with the horizon grid) or right (without the horizon grid) for an animation of the appearance of the outside Universe as you lower yourself slowly to the horizon. The Universe appears brighter and brighter as you approach the horizon, tending to infinite brightness at the horizon. ...”
    Last edited by a moderator: May 4, 2017
  2. jcsd
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