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Falling into black hole

  1. Jan 2, 2016 #1
    I know there are many threads about falling into black holes and I'm sorry for posting another one. I have a specific question and couldn't find the answer in prior threads, although it's possible that it's there somewhere. If A is outside the supermassive black hole and B falls into it, I know that A will never see B cross the event horizon. The image of B will get dimmer and dimmer from A's perspective as A's coordinate time ticks off to infinite. I know that the proper time for B to reach the singularity is finite. I know that if B is looking back at A, B will only see a finite number of photons from A, and B will not witness the progression of the entire life of the rest of the universe.
    Now imagine that B is falling in a spaceship with his rocket boosters pointed towards the black hole.​
    B can look out the front window of his ship at A. If B turns on his rocket boosters just before passing into the singularity or being ripped apart by tidal forces, and B expends an infinite amount of energy, then can B hold himself in position or slow himself and witness the entirety of the progression of events in the rest of the universe? If this is impossible after crossing the event horizon, then can B hold himself at the event horizon using this energy and witness the same thing?
    I apologize if I've assumed anything wrongly. I realize its impossible for B to have an infinite energy ​
    source on his ship.
  2. jcsd
  3. Jan 2, 2016 #2


    Staff: Mentor


    No. It is not possible to "hover" at or inside the horizon, only outside it.
  4. Jan 4, 2016 #3


    User Avatar
    Science Advisor

    Although hovering at the event horizon is impossible, hovering just outside the horizon is allowed. If one were to hover close enough, one could see as much of the future of the rest of the universe as one pleased. (And get cooked by the blue-shifted radiation).
  5. Jan 4, 2016 #4


    Staff: Mentor

    If you weren't crushed by the severe acceleration. :eek:
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