what are black holes?

Answer 1

stars that, towards the end of their life, have gotten so large, they cannot support themselves with all the gravity caused by the largeness of the star, and so they collapse in on themselves, forming a black hole. THis is where gravity is so strong, anything that gets near it is pulled into it. No-one really knows what happens once inside a black hole, but many people think that it's a bit like a backwards big bang, and you would get so much pressure on you, you would become a singularity, like the universe was before the big bang, with all matter packed into a tiny space by the forces from the black hole.

Answer 2

Black holes are theoretical entities that conform to a mathematical equation.
A black hole is supposed to result from the collapse of a 2 to 3 solar mass neutron.star.
The neutron star [15 km in diameter] can't resist the intense gravity at it's surface so it collapses into a mathematical entity about 3 km in diameter.
The surface gravity is so intense that the escape velocity is greater than the speed of light.
Since no radiation can escape the surface it would be invisible, a black hole.

Answer 3

Black holes are regions of space where gravity is so strong that not even light can escape, making them impossible to see. But we can see the stuff that is being sucked in to these massive cosmic vacuum cleaners. Anything that approaches a black hole is first torn apart by its immense gravitational force and then forms a flat rotating disc that spirals into the hole.

There are two main types of black hole - stellar and supermassive. Stellar sized black holes are the remnants of massive dead stars that have imploded. The nearest one to us is part of a binary system called Cygnus X-1, discovered in 1971. It is in the constellation of Cygnus, also known as the Northern Cross. It's estimated that our galaxy contains millions of these stellar black holes. Supermassive black holes, on the other hand, can have initial masses millions of times that of the Sun. It's now thought that they may lurk in the centre of every galaxy and be integral to the way galaxies evolve. There might also be other types of black holes, such as mini black holes, smaller (in volume) than atoms but as massive (in amount of matter) as whole mountains. Or even middle-sized black holes, mid-way between the stellar and supermassive variety. It's possible that there could be such things as 'white holes', the opposite of black holes, spewing out matter and energy into the Universe. However, this is just another of the cosmic mysteries still awaiting a solution.

Answer 4

A black hole is an illusion. It's nothing. Well if there's no light shining into the cavity it would be black but black is the absence of colour anyway so you don't see what you think you see. And with the outer edges being seen gives you the impression of a hole but it's really just space. You're looking into nothing or the abiss.

Answer 5

So many long answers, one of which looks copied and pasted from a another website!

Basic answer:
The stronger the gravitational field around a body such as a star or planet, the greater the escape velocity (the speed something needs to go to get away)
It is possible that there are bodies with such strong gravity that the escape velocity is faster than light, so light cannot escape.

So they are black.

Answer 6

BLACK HOLES

The 20th century saw a great many new discoveries regarding celestial phenomena in the universe. One of these entities, which has only recently been encountered, is the Black Hole. These are formed when a star which has consumed all its fuel collapses in on itself, eventually turning into a black hole with infinite density and zero volume and an immensely powerful magnetic field. We are unable to see black holes even with the most powerful telescope, because their gravitational pull is so strong that light is unable to escape from them. However, such a collapsed star can be perceived by means of the effect it has on the surrounding area. In Surat al-Waqi'a, Allah draws attention this matter in this way, by swearing upon the position of stars:

And I swear by the stars' positions-and that is a mighty oath if you only knew. (Qur'an, 56:75-76)

The term "black hole" was first employed in 1969 by the American physicist John Wheeler. Previously, we imagined that we were able to see all the stars. However, it later emerged that there were stars in space whose light we were unable to perceive. Because, the light of these collapsed stars disappears. Light cannot escape from a black hole because it is such a high concentration of mass in a small space. The enormous gravitation captures even the fastest particles, i.e. the photons. For example, the final stage of a typical star, three times the mass of the Sun, ends after its burning out and its implosion as a black hole of only 20 kilometres in diameter! Black holes are "black," i.e. veiled from direct observation. They nevertheless reveal themselves indirectly, by the tremendous suction which their gravitational force exerts on other heavenly bodies. As well as depictions of the Day of Judgement, the verse below may also be pointing to this scientific discovery about black holes:

When the stars are extinguished, (Qur'an, 77:8)

Moreover, stars of great mass also cause warps to be perceived in space. Black holes, however, do not just cause warps in space but also tear holes in it. That is why these collapsed stars are known as black holes. This fact may be referred to in the verse about stars, and this is another important item of information demonstrating that the Qur'an is the Word of Allah:

[I swear] by Heaven and the Tariq! And what will convey to you what the Tariq is? The Star Piercing [the darkness]! (Qur'an, 86:1-3)
http://www.miraclesofthequran.com/scientific_37.html


What does the Holy Quran say about black holes
What kinds of black holes are there?

Scientists have identified three kinds of black holes – small, medium, and large.

(1)The small one or low-mass black holes stellar or galactic black holes

These low-mass black holes form from collapsed stars that were once 100 times as massive as our Sun .

When such a massive star runs out of energy, it throws off its outer shell and is left with a core that is still 15 times as massive as the Sun

Scientists believe that our Milky Way Galaxy contains tens of thousands of these black holes, hence the name "galactic" black hole.

(2) Super massive black holes reside in the center of galaxies. Some scientists speculate that most galaxies, including our own, harbor a super massive black hole

(3) The mid-size black holes .

There are two main processes constantly going on in massive stars: nuclear fusion (which tends to blow the star's hydrogen outward from the star's center) and gravitation (which tends to pull all hydrogen back in the direction it had come). These two processes balance one another until all the star's hydrogen is exhausted, allowing gravitation to take over.

Once gravitation dominates, the star becomes unstable and starts to collapse. Once the star starts to collapse, it does not stop, and the star (and ultimately its atoms ) will cave inward upon itself, resulting in the formation of a black hool (Hewitt 186).
http://www.55a.net/firas/english/index.php?page=show_det&id=206

Answer 7

to put it bluntly, a black hole is basically a dead star

Answer 8

In Space???????????????