2006-10-13 21:11:44 · 4 answers · asked by tom science 4 in Science & Mathematics ➔ Astronomy & Space
At the event horizon, where the escape velocity = the speed of light, you can no longer shine light out even if you direct it vertically. But before then, if you direct it horizontally, it is trapped in an orbit around the black hole. That's the stage during your descent when really weird things start happening. Inside the radius where light orbits the black hole, centrifugal force acts the wrong way.
2006-10-13 21:19:26 · answer #1 · answered by zee_prime 6 · 0⤊ 0⤋
I think the point you are looking for is the Schwarzschild radius. As previously stated, you can calculate the Schwarzschild radius of any object by setting the escape velocity for that object's gravity field to the speed of light and solve the equation for radius. This tells you that once you compress an object to within that radius, light can not escape. The Schwarzschild radius of the sun is about 3km and the Schwarzschild radius of the earth is about 9mm.
2006-10-14 13:25:11 · answer #2 · answered by sparc77 7 · 0⤊ 0⤋
Are you talking about a singularity or a black hole? They are not quite the same thing.
2006-10-13 23:17:24 · answer #3 · answered by andyoptic 4 · 0⤊ 0⤋
I'm not sure I understand the question. Are you asking about the apparent horizon of a black hole?
2006-10-13 21:16:17 · answer #4 · answered by Kuji 7 · 0⤊ 0⤋