- #1
Tom Mcfarland
- 32
- 2
Suppose I am orbiting a black hole (BH) at some distance d outside its event horizon (EH), and with orbital velocity v.
I do not like where I am, so I try to increase d by using an amount E of energy to increase my orbital velocity to v', where v' is whatever is necessary to escape the BH and reach a velocity of zero at d = ∞ (relative to the BH) .
My understanding is that as the initial distance d shrinks to zero, the amount of energy E required to escape to distance d = ∞ increases without bound, that is, E approaches ∞ . If my "understanding" here is incorrect,
then the following question evaporates, but another question would then arise.
OK, now reverse this process...I start at (d = ∞) and fall toward the BH, converting my newly acquired potential energy into kinetic energy (or any other form of energy). I reacquire as kinetic energy the same E as that which I needed to escape, where E increases without bound as my d shrinks to zero. If I where close enough to the BH, I would acquire more kinetic energy than currently exists in the entire universe, and would continue upwards from there !
Since the universe is not flooded with energy, this scenario seems to imply that I can never reach the EH.
Yet BH forums frequently send cosmologists across an EH. Where is my misconception?
I do not like where I am, so I try to increase d by using an amount E of energy to increase my orbital velocity to v', where v' is whatever is necessary to escape the BH and reach a velocity of zero at d = ∞ (relative to the BH) .
My understanding is that as the initial distance d shrinks to zero, the amount of energy E required to escape to distance d = ∞ increases without bound, that is, E approaches ∞ . If my "understanding" here is incorrect,
then the following question evaporates, but another question would then arise.
OK, now reverse this process...I start at (d = ∞) and fall toward the BH, converting my newly acquired potential energy into kinetic energy (or any other form of energy). I reacquire as kinetic energy the same E as that which I needed to escape, where E increases without bound as my d shrinks to zero. If I where close enough to the BH, I would acquire more kinetic energy than currently exists in the entire universe, and would continue upwards from there !
Since the universe is not flooded with energy, this scenario seems to imply that I can never reach the EH.
Yet BH forums frequently send cosmologists across an EH. Where is my misconception?