I told you to stop trying to make me think!

Ok, let's take your points 1 at a time.

re: Red Shift - I am trying to avoid the use of the word infinite, because no body seems to be able to come up with a good working use for it. But yes, the wavelength becomes infinite, and the frequency drops to zero. Keep in mind that an infinite wavelength means that the wave is smeared over the whole universe. Actually I believe that some work has been done which suggests that the light quanta are smeared over the surface of the horizon. I think, but am not sure, that I kind of got that idea from "The Black Hole War" by Leonard Susskind.

re: time slowed to zero - The idea of a rest frame for light is problematic, so let's say that time in a reference frame located at the horizon would apparently be slowed to zero as compared to our clocks. Keep in mind that in the frame at the horizon time would appear to move normally. If you were to fall into a sufficiently large black hole you would be able to fall all the way into it without the tidal effects pulling you apart, because the center of mass would be far enough away that they would be minimal. So as you fell through the horizon you would not notice any special effects. But from a distant observer you would appear to be torn apart and swallowed up. Hey, you thought just QM was crazy?

re: escape velocity - That is one of the poorer ways of describing the black hole horizon. However, it was what the first discussion of a sort of black hole was based on. Escape velocity is the velocity a mass has to have to escape from the gravitational attraction of another mass. If you throw a rock into the air it will slow for some period of time, then come back down and hit you on the head. If you throw it harder it will go up farther and take longer to hit you on the head. At some velocity it will reach a velocity that it will never come back down. That is escape velocity. Well, somebody started looking at that and imagining larger and larger planets, and figuring the escape velocity. This was a purely Newtonian calculation, done long before Einstein. He reached the conclusion that a sufficiently large star could have an escape velocity greater than the speed of light. He was pretty much ignored, but the idea was still kind of floating around. Then when Einstein invented GR Chandrasekhar used to conclude that they were theoretically possible. But escape velocity is still one of the relatively simple ways to explain it. Now after that digression, back to your problem. When a photon, traveling at light speed, reaches the horizon, it has used all the energy it has, and falls back into the interior. Of course since it now has zero energy, it also has a zero frequency, so we are back to the red shift. In fact just about all the ways of looking at how a black hole works are just different ways of saying pretty much the same thing.

Now I hope that is confusing enough.

Bill Gill


C is not the speed of light in a vacuum.
C is the universal speed limit.