View Single Post
Dec7-08, 11:47 PM
PF Gold
P: 247
Quote Quote by MuggsMcGinnis View Post
If it's possible to interact with the in-falling object, no matter how long one waits, how can we presume that the object actually falls through the event horizon in finite time?
By building this spacetime in general relativity and then measuring the proper time on the infalling body worldline.

Quote Quote by MuggsMcGinnis View Post
It's easy to see how Hawking radiation would cook any in-falling object. As the black hole shrinks, its temperature increases and it radiates more energy per second. The in-falling object is getting closer to this surface that's getting hotter. Also, time is slowing for the in-falling object so the quantity of energy it sees radiating from the event horizon is even greater, per unit of time. All of these factors combine so that (I'm guessing) the apparent temperature that the in-falling object is subjected to approaches infinite as the remaining lifetime of the event horizon approaches zero. It would end with one infinitesimal instant of infinite temperature.
No, the infalling (free-falling) body will cross the event horizon right away, when the black hole is big, and the temperature of the horizon is low. Distant observers will see in the same distant future the last photons emitted in the distant past by the infalling body mixed with the photons from the black hole final explosion by evaporation.