I don't understand~ What exactly *IS* a Black Hole?

Question

Can you explain it to me, I don't get it! Do they exist?

Answer 1

To understand a black hole, you have to understand how stars shine. Stars are essentially clouds of gas being compressed by gravity. The only reason why the gravity doesn't completely compress the cloud is because the light being produced by the star through nuclear fusion provides an equally opposing force pushing outward. Eventually the star runs out of "fuel" for nuclear fusion and stops emitting light. When this happens, the gravity takes over and shrinks the star. The pressure increases greatly and the star then "pops". The star is now a great deal larger and cools down giving it a red coloration and the name of "red giant." The star will then collapse again. If the star is large enough, it will collapse so quickly that the temperature and pressure increase so much that the star explodes in a supernova. While the supernova is throwing pieces of the star out into space, it also pushes some of the star inward. This force is so strong, that it even propells the electrons of each individual molecule into the nucleus where they combine with the protons. If the star possess enough mass the gravity will pull these nuclei together so they are just one solid chunk of mass. This solid mass has enough gravity now that no light can escape from it. It is now a black hole.

Answer 2

Yes, black holes exist. Basically a black hole is created by a dieing star. There isn't enough known about black holes to sufficiently explain what they truly are but there are different theories like, after some stars die, meaning they eventually burn up all there fuel through nuclear fusion, they implode instead of explode creating a well of gravity so strong that nothing can escape it and at it's center is a quantum singularity. Again what a quantum singularity is no one can explain only theorize. There are theories that at the center are worm holes that lead to other parts of the universe or even to other dimensions.

But to put it simply a black hole is a gravity well that would probably look like a flat fat tornado in space that nothing can escape once it comes into contact with it's gravity wall.

Answer 3

OMG, I am so shocked by so many stupid answers here.

A "black hole" is defined as a spot of super-dense mass in space with a gravitational pull so high, even light cannot escape. Some say, it would be a so called singularity, a point infinite small but not zero.

What all the other users try to explain, how black hole are created and why ... but that wasn't your question.
Yes, briefly said, ia black hole usually results from a super nova, so to speak, a dying star (Attention, not every dying star ends up in a super nova)

So now, why is it called black hole?
Black, because even light cannot escape, so it is a spot in space where it is just plain dark (we equal that with black)
and hole, because we can see effects we know from holes in the soil on earth. If you put water in a tank with a hole in it, what happens? Water starts to revolve around the whole while disappearing in it. We can watch the very same effect around black holes. The gravitational pull is so big, that they "swallow" each matter around them, that came too close. But before the matter "disappears" in the black hole, it starts revolving ...
Due to these visibly comparable effects, they named it "hole".
But it isn't a hole as like as we understand it on earth.

Now put the two together and your result is "black hole".

Answer 4

Black holes are predicted by Einstein's theory of General Relativity. We have never directly observed one (and indeed, it will be impossible to ever directly observe one), but we believe we have detected the existence of several by the side-effects of their gravity.

As another responder said, a black hole is an object that is so massive that even light cannot escape from its surface. The outer boundary of a black hole is called its 'event horizon' -- once something (including a beam of light) crosses the event horizon, it will never been seen again in this universe.

In principle, a black hole can be formed when a very old star collapses in upon itself. It's own gravity causes it to "implode", getting smaller and smaller until, effectively, it disappears from the universe.

Answer 5

Short & Simple - it is a concentration of matter where the gravitational forces are so great that light cnnot escape. Because light can't escape, it is black. We detect black holes by how light bends around them or through the detection of x-rays emitted from the poles.

Some theories suggest that a black hole reduces matter to a "singularity" which is just an infinite smal but non zero point.

Answer 6

Yes, Black Holes do exist. They have been "sighted" by scientist and are not theoretical. While it is very complex the long and short of it black holes are very very VERY large stars that have since died out. They got so big that they collapsed in on themselves. They are so heavy that they actually warp space and time around them. To help you visualize this, think of the universe as a blanket being being stretched out by it corners, now put something on it like a marble. You can see that the marble very slightly causes a depression in the blanket. Think of the marble as our sun. Now picture taking a bowling ball and putting that on the blanket. Now there is a huge depression in the blanket, it might even rip through it. Now picture you have marble that's as heavy as the bowling ball on the blanket. That would be like a black hole. In fact, real black holes create so much gravity (that's what I mean by being heavy) that nothing can escape its gravity, not even light. That's why they're called black holes, because no light can reflect off of them they appear black.

Answer 7

Black holes are the result of very large stars and black holes can eat other black holes to create massive black holes. These black holes would probably create light like the simular white dwarfs, but the gravitational pull is so strong that light can't escape. They are called black holes, not because they are holes, but because they create the appearance of nothingness where somebody would expect something (like the center of the galexy).

Answer 8

A black hole is a point is space where a star (or stars) has collapsed down to the point where its entire mass is a ball only a few centimeter or even a few millimetres or less in diameter. The gravitational pull of a black hole is so massive that the escape velocity is faster than the speed of light (186,282 miles per second). The escape velocity of the earth is 7 miles per second.

They do exsist. there is supposedly one in the centre of out galaxy.

Answer 9

A star (like our sun) produces light and energy when the nuclear fusion inside it take place. Hydrogen combining as fusion materials to form Helium and so on. When all the fuel is used up, the star collapses. Then the reverse process starts when the energy is absorbed. At this stage any matter or energy closer to this star is absorbed and this is called a black hole. As anything is taken in.

Answer 10

our sun shines steadily year after year,but not all stars are so stable. some old stars change size every few days or weeks.these are known as pulsating variables.some stars change bcoz they belong to double star systems.some stars are so close to each other that one pulls gas away frm other.the more pwrful star collects enough gas to sett off an explosion called 'nova'.after the explosion star collects gas again.they collect so much gas that they blow apart as supernova.the star is completely destroyed.supernovas also occur at d end of giant stars life.when their fuel runs out,they explode,crushing their deep core into a neutron star or a 'black hole'.they r exteremly dense city size spheres that spin very rapidly.blackholes are infinitely dense and swallow anything that comes close to them-even light!!!