2007-01-27 01:39:40 · 6 answers · asked by Anonymous in Science & Mathematics ➔ Physics
A black hole is an object predicted by general relativity,[1] with a gravitational field so powerful that even electromagnetic radiation (such as light) cannot escape its pull.[2]
A black hole is defined to be a region of space-time where escape to the outside universe is impossible. The outer boundary of this region is called the event horizon. Nothing can move from inside the event horizon to the outside, even briefly, due to the extreme gravitational field existing within the region. For the same reason, observers outside the event horizon cannot see any events which may be happening within the event horizon; thus any energy being radiated or events happening within the region are forever unable to be seen or detected from outside. Within the black hole is a singularity, an anomalous place where matter is compressed to the degree that the known laws of physics no longer apply to it.
Theoretically, a black hole can be any size. Astrophysicists expect to find black holes with masses ranging between roughly the mass of the Sun ("stellar-mass" black holes) to many millions of times the mass of the Sun (supermassive black holes).
The existence of black holes in the universe is well supported by astronomical observation, particularly from studying X-ray emission from X-ray binaries and active galactic nuclei. It has also been hypothesized that black holes radiate an undetectably small amount of energy due to quantum mechanical effects. This is called Hawking radiation.
2007-01-27 01:47:58 · answer #1 · answered by landhermit 4 · 2⤊ 1⤋
Well, I assume since you have asked this question that you know what black holes are and you have understanding of space-time curvature. As per relativistic theory, every ojbect with significant mass has an effect on space-time and causes curvature of space-time. Gravitional field causes sloing down of time called the "time-dilation" So, what is different incase of "black holes". Space-time curvature becomes infinite. time comes to a standstill for a observer inside the black hole. You need to read more about singulairty. I suggest you start reading with this refernce, go down to the topic on space-time distortion and singularity. this is a very complex topic to understand.
2007-01-27 10:01:10 · answer #2 · answered by Anand 2 · 2⤊ 1⤋
They're not.
All matter distorts spacetime, when a star with large enough mass collapses in on itself it will collapse right down to a point and the escape velocity needed becomes faster than light. Therefore it cannot be seen (though it would not look black as people sometimes claim).
If you want to learn about blackholes I recommend Hawking's book 'a brief history of time' or looking on www.space.com.
2007-01-27 09:52:54 · answer #3 · answered by Anonymous · 2⤊ 1⤋
It is more like the intense gravity of black holes causes space time to bend under their influence.
2007-01-27 09:47:39 · answer #4 · answered by Jerry P 6 · 1⤊ 1⤋
Their intense gravity bends the space-time continum, in line with Einstein's equations, as does our sun to a much smaller degree.
2007-01-27 09:48:40 · answer #5 · answered by Mike1942f 7 · 2⤊ 1⤋
wanna have dinner tonight ? i could eat some Ethiopian! what do you feel like girl?
and don't say a salad!!!!
2007-01-27 09:42:22 · answer #6 · answered by lowroad 2 · 1⤊ 2⤋