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Question about events inside black holes

  1. Nov 13, 2007 #1
    Hello, I am currently an undergraduate student and have an interest in black holes, but my lack of mathematical background is giving me some difficulty understanding some of the ideas. I found an article on the Cornell website that has been bothering me for awhile. The article states that it is possible to see future events when you are inside the event horizon of a black hole. Here is a link:

    http://curious.astro.cornell.edu/question.php?number=652 [Broken]

    I have looked through books dealing with black holes, but have not found any that discuss this ability to see events from the future, so I am having a hard time understanding what she is talking about. Could someone here please explain to me what the author is describing when she says you can receive light signals from the future when inside the event horizon?
    Last edited by a moderator: May 3, 2017
  2. jcsd
  3. Nov 13, 2007 #2


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    This seems to me to be confusingly worded. It is true that you can 'see' events that happen at a value of the Schwarzschild 't' coordinate that is greater than your own Schwarzschild 't' coordinate, but the point is that inside the event horizon, this coordinate measures distance, not time.

    I would say that such events are not in your future, they just have a greater value of the 't' coordinate.
  4. Nov 14, 2007 #3


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    Also, even if the event had a greater Schwarzschild t-coordinate than the event of your seeing light from it, the event still lies in the past light cone of the event of your seeing it, and in relativity light cones, not coordinate time, are the physical way that "past" and "future" are defined.
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