2006-10-01 14:59:26 · 3 answers · asked by tom science 4 in Science & Mathematics ➔ Astronomy & Space
Every black hole is surrounded by an event horizon. At this point anything, including light would have to exceed the speed of light at this point to exit it. These same particles would have to continue to accelerate and therefore exceed the speed of light. Radiation is either an energetic photon or a larger subatomic particles some of which can move at 99.9% the speed of light. Until radiation reaches the event horizon then it has a chance to escape the black hole. Past this point we cannot see what is happening because to see something the light from the event would have to exceed the speed of light.
X-rays are very energetic subatomic particles that are generated by black holes with the collision of matter falling into the black hole. The X-rays act like a searchlight showing the presence of some active black holes. But, some of this radiation is aimed where the black hole can get it so it doesn't all escape.
Check out this article: http://archive.ncsa.uiuc.edu/Cyberia/NumRel/BlackHoleAnat.html
In it you will find that the German astrophysicist Kurt Schwarzschild discovered the event horizon so it is often called the Schwarzschild Radius.
Read this Wikipedia article as well: http://en.wikipedia.org/wiki/Event_horizon
Stephen Hawking said that since the black hole has no radius, only a point, while the event horizon has a positive radius, and since all the particles inside the black hole have to fall across this radius then conventional physics has a problem. For these particles to move faster than the speed of light is impossible, therefore the laws of physics break down and we cannot understand what is happening.
ANYTHING can be going on inside of the Schwarzschild Radius, literally anything. Magic might work; time might run backwards, and so on. Seeing any of this happen could drive even a sane man insane, (it sure would drive an astrophysicist nuts) so all black holes are decently surrounded by an event horizon.
2006-10-01 15:19:50 · answer #1 · answered by Dan S 7 · 0⤊ 0⤋
When the radiation crosses the event horizon.
2006-10-01 22:02:22 · answer #2 · answered by fetchrat 3 · 3⤊ 0⤋
Yo, Tom Science, good to see you are back!
I was going to say as soon as it crosses the event horizon but DanS's answer is more informative.
2006-10-02 00:26:02 · answer #3 · answered by THE CAT 2 · 0⤊ 0⤋