2006-07-24 22:38:39 · 13 answers · asked by dagger 2 in Science & Mathematics ➔ Astronomy & Space
A black hole is a concentration of mass whose gravitational field is so strong that nothing can escape. Black holes are predicted by general relativity. Under the description provided by general relativity, as an object moves closer to a black hole, the energy required for it to escape continues to increase until it becomes infinite at the event horizon, the surface beyond which escape is impossible. Inside the event horizon, the geometry of spacetime is distorted in a way that makes moving closer to the central singularity inevitable no matter how the infalling object moves.
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 been hypothesised that black holes radiate energy due to quantum mechanical effects (known as Hawking radiation).
The concept of a body so massive that not even light could escape was put forward by the English geologist John Michell in a 1784 paper sent to the Royal Society. At that time, the Newtonian theory of gravity and the concept of escape velocity were well known. Michell computed that a body with 500 times the radius of the Sun and of the same density would have, at its surface, an escape velocity equal to the speed of light, and therefore would be invisible.
Black holes do not swallow up things with voracity. In fact, if the Sun were replaced with a black hole of the same mass, the Earth would not spiral into the dark abyss, for the gravitational force would still be the same at distances larger than the radius of the Sun, based on the masses and distance between them. The Earth would rotate around the solar-mass black hole as though it was still a normal star.
They are INVISIVLE.
2006-07-24 23:40:27 · answer #1 · answered by PrAt 3 · 4⤊ 0⤋
A black hole is invisible, so any color one would view would be a mere reflection of it's surroundings, as limited as that would be. Probably not detectable to the naked eye.
2006-07-24 22:44:49 · answer #2 · answered by Anonymous · 0⤊ 0⤋
But before we must understand : to which
reference frame does the “ black hole” belong?
2006-07-25 01:51:09 · answer #3 · answered by socratus 2 · 0⤊ 0⤋
It is black in the middle. The light and particles drawn towards it are only seen around it.
Why it is black is that the gravitational pull is such that it pulls even light towards it.
2006-07-24 22:45:52 · answer #4 · answered by R G 5 · 0⤊ 0⤋
it's a black hole because everything gets sucked in...even light..
no light = dark = black
Cheers
2006-07-24 22:43:56 · answer #5 · answered by feizal 1 · 0⤊ 0⤋
It is, of else it wouldn't be called a black hole innit
2006-07-24 22:46:33 · answer #6 · answered by Ichi 7 · 0⤊ 0⤋
theoretically, it is so dense that its gravitational pull sucks in everything, including light. So, it is black in color.
2006-07-24 22:42:23 · answer #7 · answered by Kathleen C 2 · 0⤊ 0⤋
Because it absords light... and the background is black...
Guess its colour would be defined by whatever was being swallowed by it...
2006-07-24 22:42:20 · answer #8 · answered by Forlorn Hope 7 · 0⤊ 0⤋
But it IS black!!!
2006-07-25 00:20:50 · answer #9 · answered by Vasudha 3 · 0⤊ 0⤋
It absorbs all light and therefore is black.
2006-07-25 03:52:14 · answer #10 · answered by tkron31 6 · 0⤊ 0⤋