01 Jun 07
Originally posted by mlpriorx-rays are emitted OUTSIDE the event horizon of the black hole
Here is a question I have been pondering lately in my free time, maybe someone here knows the answer.
If a black hole has such a huge gravity, how does it emit x-rays?
That is, how could the x-rays possibly escape the gravity of a black hole?
01 Jun 07
Originally posted by mlpriorIt is called Hawking radiation, Stephen Hawking figured out when there is a changing gravitational field, a big gradient, when radiation hits the gradient, some of it reverses direction and gets thrown out and some enter never to be seen again. There is an article in one of the latest Scientific American that suggests flowing water can be used to simulate the way radiation behaves near the event horizon of a black hole, the gradient in this case is a changing water velocity and they shoot sound waves into say, a water jet that goes into a decreasing sized pipe, that creates the pressure differential and sound waves behave exactly like light waves do near the event horizon. It is work that can help understand black holes, hopefully, that is to say, they hope the water analogy is very close to the same in a black hole, so they can study black holes in ways they never could do in nature.
Here is a question I have been pondering lately in my free time, maybe someone here knows the answer.
If a black hole has such a huge gravity, how does it emit x-rays?
That is, how could the x-rays possibly escape the gravity of a black hole?
01 Jun 07
Originally posted by sonhouseHawking radiation wouldn't be that powerful. The X-rays emitted by black holes are due to matter being shredded on its way into the black hole. Basically something (a star, planet, lump of gas) gets caught in an ever decreasing orbit and is eventually tidally disrupted. The matter from said object then spreads out around the black hole in an accretion disc. Friction forces within the disc heat the gas to huge temperatures and X-rays are the result.
It is called Hawking radiation, Stephen Hawking figured out when there is a changing gravitational field, a big gradient, when radiation hits the gradient, some of it reverses direction and gets thrown out and some enter never to be seen again. There is an article in one of the latest Scientific American that suggests flowing water can be used to simulate t ...[text shortened]... o the same in a black hole, so they can study black holes in ways they never could do in nature.
01 Jun 07
Originally posted by Kepleryeah, that's the ticket!!!
Hawking radiation wouldn't be that powerful. The X-rays emitted by black holes are due to matter being shredded on its way into the black hole. Basically something (a star, planet, lump of gas) gets caught in an ever decreasing orbit and is eventually tidally disrupted. The matter from said object then spreads out around the black hole in an accretion disc. Friction forces within the disc heat the gas to huge temperatures and X-rays are the result.