Do black holes exist? If so, what are they?

Question

And how do we know?

Answer 1

Please see the link below

Answer 2

I can give it to you simply, rather than those first two that had like 10 pages worth of stuff.

Yes, the exist, but like it has been said, what they do is based on theries. Yes, they suck in light. They suck in all matter.

Something I only found out a few weeks ago is that galaxies have spiral shapes because in the middle there is a black hole sucking everything in like a whirlpool. How cool is that???

There's plenty more but this answers your question.

Answer 3

so black holes exist and take place after a supernova explosion if the star is too massive through its stages of its "evolution".. it has high gravitational field strength and due to its extreme gravity, even light cannot escape through it..

For more info. ask pilina->my physics teacher :p

Answer 4

It is very hard to explain back holes but the best analogy is a two dimensional  example. Take a strong  and flexible latex membrane that's used in balloons. Stretch it out now pour water into the middle. The water will create bulge with a small entry hole. From the top there is very little to be seen except for a small hole. If you have a galvanometer you will detect an existence of a large mass. So black hole are in effect in space-time dimension ( 3dimension plus time). They are small but very heavy. If the sun was squeezed as a black hole it would be smaller than the Earth.

Answer 5

We do not know if they actually exist. It certainly "appears" that they do and I happen to believe that they do BUT they are (as of today) only a theoretical model to explain some very definite and intriguing effects that we see in the universe.

Others here have explained the theory very well so I won't go into it but I do want to say that it's ONLY a theory,even if it is our best one so far.

Answer 6

apparently its just a theory gees you learn something new every day. All the information available about black holes and its only a theory, wow thats mind numbing.

Answer 7

of course they exist! in the middle of all active galaxies there are super massive black holes, they once were massive stars or supernova explosions which after having no light elements(to supply them with heat to push against gravity and obtain equilibrium) they started to collapse under their own gravity and they are so massive that they don't even allow light to escape from them so they appear dark. i suppose u dont want more details.

we know they exist, based on a few observations, einstein rings(gravitational lensing) is one. say there is a black hole between us on earth and a large luminous galaxy, as you know the light from the galaxy goes to all directions( if there was no black hole in the middle of the way, we could see the galaxy from the lights that came straight towards the earth) but now what we see is a ring, because the black hole blocks those light rays that were coming straight towards us and will bend the light rays from other directions toward us so we will see a ring. a black Hole with a luminous ring around it and around this hole we will see multiple pictures of the same galaxy, (as the light of each can be analyzed), so we know there is a black hole there.

and also Stephen Hawking discovered that black holes aren't so black after all. because of a process called pair production   , which occurs just outside the event horizon, black holes emit infrared radiations which can be observed, from here on earth, so if with normal telescopes you see a very dark region, but with infrared telescopes you see a very active region then you know you have detected a black hole.

and if you are only questioning the existence of black holes i should tell you that with the large hydron collider, we are able to create tiny black holes right here on earth!( they of course evaporate in micro seconds)

the radius of a black hole known as schwarzshild radius can be calculated by the formula r=Gm/(c^2)

where r is the schwarzschild radius

G is gravitational constant

m is the mass of the object

c is the speed of light

the schwarzschild radius of an object with the mass of the sun would be about  only 3 kilometers.

I think i must clarify that black holes are NOT theoretical models, there are supermassive objects out there in the sky with radii less than the schwarzshild radius and pass all the criteria of being a black hole, they have names for gods sake!

they created black holes in large hydron collider!

Answer 8

OK, basically, a black hole is a region of space. Imagine a balloon. The air inside is the space in the black hole. The "skin" of the balloon is the event horizon. Things go in but not out. It even sucks in light and because it doesn't let it back out, we don't see the actual insides of a hole, we only see surrounding matter being sucked in.

OK, here it gets tricky.

The center of the balloon is a point of gravity distortion. I produces super gravity, so the balloon actually pulls stuff in.

The closer you get to one of those b*tches, the slower time goes for you. Time is relative, so to an outside observer, you would just be frozen in time in front of the hole. From your point of view you go at the speed of light towards the center of the hole.

Hope it helps.

Answer 9

yes,black holes ae invisible "drains" in space that suck everything into them including light, thats why they are invisible.

Answer 10

As everyone has previously explained, Black Holes are currently only a theory.  Until we are capable of interstellar travel, we are only able to hypothesise about their existence.  However, Cygnus X-1 is one of the first (and probably best known) potential Black Holes.  At the moment, we are only able to assess Cygnus' eligibility as a Black Hole via Earth-based equipment; but maybe one day we'll have enough evidence to prove this theory as a valid one.