Since I am totally unable to understand Hawking, I suppose I am qualified to give the obvious answer, and not feel too bad about being wrong (-: Mary, while watching the black hole shrink, sees the red-shifted image of Joe disappear. This happens after a sufficient length of time that Joe's image has already been redshifted so far that the uncertainty principle (viewed as the energy-time relation ∆E∆t > h) prevents Mary from distinguishing when Joe's red-shifted image became invisible. So the "paradox" created by quantum effects (i.e. Hawking evaporation) is also resolved by quantum effects. On 5/27/12, Warren Smith <warren.wds@gmail.com> wrote:
Joe jumps into a Schwarzschild black hole. Mary stays behind and watches him fall.
The standard stories are then as follows: [...] 4. NOW, new addition to above stories. The black hole gradually is shrinking due to "Hawking radiation." It will vanish completely in about 10^70 years (let's say).
So Mary, who is very long-lived, will then say "the new state of the universe is: there is no black hole anymore, Joe never quite fell in, and so Joe is still with us. In fact, I'm going to go meet him now, since he's only 1 hour older by his personal clock."
But Joe will say "I fell in, I was crushed into a point, and my mass-energy was Hawking-radiated away. I'm gone."
How do you resolve this paradox?
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