How can a black hole be black? If no light can escape surely it cannot be a colour!?
452076
black is a colour!\nno colour would be clear, invisible. if that was the case you would then see a bubble of magnified/distorted/warped space stars behind it. but that's not the case.\n\nimagine seeing a black hole with your eyes. you would see stars everywhere except at the hole which would be black...colour.\n\nisn't black not the absence of colour but rather the accumulation of all colours?
21273
I've heard some call black matter a blackhole. The honest truth is we just dont know. Its a theory nothing more. A human concept to TRY to understand something. \n\nLike the notion of "time". We measure that based on our small experiences within our solar system. For all we know there could be a larger, grander universal measurement.
312029
As moses said very well indeed, Nobody knows.\nThe major problem I have with a black hole is why it is called a black hole. If this thing is so dense and gravity is so powerful it would be bending light around at the event horizon so that you'd not even know the black hole is there. The other way to confirm this "black hole" would be to observe the planets remaining in the solar system still rotating around a sun which is not there any more. What you would actually confirm would be, according to the laws of gravitational attraction that two massive bodies are attracting each other. One is the planet you see and the other is the "black hole.\nWe know we can change things by sqeezing them, coal into diamonds etc, but there are some materials such as water that are supposed to be incompressible.\nWhat we are supposed to think is the acceleration gradient is so massive that atoms are stripped into their components.\nThe thing is, if the graviation is so massive beyond the event horizon that things are moving at the speed of light.\nThis is a contradiction according to the relativistic E=MC^2 equation.\nIn order for something to travel at the speed of light it must have no mass.\nWe know light has no rest mass.. I.e. stop some light and you get energy but nothing to look at.\nTherefore we are supposed to assume that a massive body changes into pure energy to reach the speed of light and then turn back to mass when it gets to the centre of the black hole.\nThe conclusion there is neither mass nor energy according to the laws of physics currently at the centre of a black hole.
387898
Black holes are food for my brain and curiosity. I love the subject it is so interesting!\nBackround info: A black hole is a concentration of mass great enough that the force of gravity prevents anything from escaping from it except through quantum tunneling behavior. The gravitational field is so strong that the escape velocity near it exceeds the speed of light. This implies that nothing, not even light, can escape its gravity, hence the word "black." The term "black hole" is widespread, even though it does not refer to a hole in the usual sense, but rather a region of space from which nothing can return. Theoretically, black holes can have any size, from microscopic to near the size of the observable universe.\nBlack holes are predicted by general relativity. According to classical general relativity, neither matter nor information can flow from the interior of a black hole to an outside observer. For example, one cannot bring out any of its mass, or receive a reflection back by shining a light source such as a flashlight, or retrieve any information about the material that has entered the black hole. Quantum mechanical effects may allow matter and energy to radiate from black holes; however, it is thought that the nature of the radiation does not depend on what has fallen into the black hole in the past.\n\nThe existence of black holes in the universe is well supported by astronomical observation, particularly from studying supernovae and X-ray emissions from active galactic nuclei.\nMy answer 1)time travel when you, or in this case an object, goes fast the world goes slow. and if something, a black hole, is going, or sucking, fast enough, the world around you will eventually begin to reverse.
13072
A black hole is defined as a place where light can not escape due to the gravitational force.  The proof that they exist are the equations of gravity and experiments in labritories where miniture black holes have been created that evaporate in nanoseconds.
603896
A black hole is a concentration of mass great enough that the force of gravity prevents anything past its event horizon from escaping it except through quantum tunnelling behaviour (known as Hawking Radiation). The gravitational field is so strong that the escape velocity past its event horizon exceeds the speed of light. This implies that nothing, not even light, inside the event horizon can escape its gravity. It is, however, theorized that wormholes can provide an exit path for energy or matter. The term "black hole" is widespread, even though it does not refer to a hole in the usual sense, but rather a region of space from which nothing can return.\n\nThe 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.
144870
We have no idea what happens to any matter inside a black hole. The laws of physics that we know do not apply.
81743
A black hole is a concentration of mass great enough that the force of gravity prevents anything from escaping it except through quantum tunnelling behaviour (known as Hawking Radiation). The gravitational field is so strong that the escape velocity near it exceeds the speed of light. This implies that nothing, not even light, can escape its gravity.This makes this object invisible to the rest of the universe,hence the word "black". The term "black hole" is widespread, even though it does not refer to a hole in the usual sense, but rather a region of space from which nothing can return.\n\nThe 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.\n\nGeneral relativity (as well as most other metric theories of gravity) not only says that black holes can exist, but in fact predicts that they will be formed in nature whenever a sufficient amount of mass gets packed in a given region of space, through a process called gravitational collapse. For example, if you compressed the Sun to a radius of three kilometers, about four millionths of its present size, it would become a black hole. As the mass inside the given region of space increases, its gravity becomes stronger   or, in the language of relativity, the space around it becomes increasingly deformed. Eventually gravity gets so strong that nothing can escape, an event horizon is formed, and matter and energy must inevitably collapse into a singularity.\n\nA quantitative analysis of this idea led to the prediction that a star remaining about three times the mass of the Sun at the end of its evolution, will almost inevitably shrink to the critical size needed to undergo a gravitational collapse. Once collapse starts, it cannot be stopped by any physical force, and a black hole is created. This is because there is a limit to the strength of materials due to the fact that the speed of sound, related to the materials stiffness, cannot be greater than the speed of light.\n\nStellar collapse will generate black holes containing at least three solar masses. Black holes smaller than this limit can only be created if their matter is subjected to sufficient pressure from some source other than self-gravitation. The enormous pressures needed for this are thought to have existed in the very early stages of the universe, possibly creating primordial black holes which could have masses smaller than that of the Sun.\n\nSupermassive black holes are believed to exist in the centres of most, (if not all) galaxies, including our own Milky Way. This type of black hole contains millions to billions of solar masses, and there are several models of how they might have been formed. The first is via gravitational collapse of a dense cluster of stars. A second is by large amounts of mass accreting onto a "seed" black hole of stellar mass. A third is by repeated fusion of smaller black holes. Finally it may be possible to construct such a black hole by the collapse of a large gas cloud via an intermediate stage of a relativistic star.\n\nCertain models of unification of the four fundamental forces allow the formation of micro black holes under laboratory conditions. These postulate that the energy at which gravity is unified with the other forces is comparable to the energy at which the other three are unified, as opposed to being the Planck energy (which is much higher). This would allow production of extremely short-lived black holes in terrestrial particle accelerators. No conclusive evidence of this type of black hole production has been presented, though even a negative result
453304
There are many thoeries to how this process works...we all know that black holes are the decayed from of a supermassive star.  Technically the universe would have to all collapse before it could expand...like a star it has massivle amouts of atomic energy, and non atomic...al matter was inside this small, infinitely dense space.  Then, the big bang appeared and everything expaned.  My personal theory or space time is that there is no limate to space therefore there is no limit in time...there is no beginning or end to either becaus they are related to each other and mush remain at a simimal or equal constant.  Thus everything within time has a finite length.  The events in time will end, but not time itself.  There is a lot to all of these theories.  Anyways the point to this is that there is a center to the universe but not space.  Anything that is a mass has some ammount of gravity...some, though have more energy than others.  This is what makes a black hole.  the things in a black hole are packed into an infinitely small space.  Then hydrogen plasma shoots out of some supermassive blackholes.  this energy still remains a mysterty to me on how it can escape the black hole, almost like the big bang, but more controlled.  there WAS a mass at the center of everything, but how that works still is a mystery.  I think that there were once supersupermassive aters where the center of our calaxy is today.  this explain the expansion of out galaxy and the surrounding stars and such.  So there was once a biis mass that keeps dividing till it smaller.  Sadly at the end of our universe, everything will once again be absorbed.  That last part is my thoery.  But can we survive?  Well I hope I answered you're question thurough enough.  My hands are kinda tired.\n\nBTW...does the stuff I said too confusing or does it work..I'm not exaclty the sharpest when it comes to these things but I'm pretty sure I know what I'm talking about?
143483
Sunlight from the Sun would have to reflect off something in space in order for that region of space not to appear black.  For example the Moon doesn't look black because Sunlight is reflecting off its surface.\n\nSpace is for the most part black since there is an absence of material that can produce or relfect light there.
591084
Another name for a black hole is "Quantum Singularity"\n\nAll the matter in the black hole has collapsed under its own weight to an infinitely small point. (there's the clue)\n\nAn infinitely small point would have no Length width or depth.\nAs time ceases from our perspective, once inside the event horizon, there is no time.\n\nHence a black hole is dimensionless no space/no time.\n\nWell that's how I see it anyway!!\n\nLet the argument rage on
67663
*puts on cokebottle glasses*\nTechnically, black holes haven't been proven to exist, their existence is just extremely well supported, like the theory of plate tectonics.\n\nAlso, black holes don't actually move faster than the speed of light.  Nothing can move faster than the speed of light in a vaccuum. What you're probably thinking of is their gravitational pull is so intense that their escape velocity (the speed you have to be traveling at to break free of their gravitational pull) is faster than the speed of light.\n\nI think it's awesome in the biblical sense.  Black holes have always intrigued me- something that you can get stuck in and never, ever escape.  The way they distort light also is very interesting.\n\nI sometimes pretend that the inside of the event horizon of a black hole is where Hell is.  You can't escape it so you would be stuck there for eternity (the slow Hawking radiation notwithstanding) and you would be ripped up into your individual subatomic particles.  Plus, the rules of Classical Physics don't work in the way you would expect them to.\n\nCloyvin.
383398
Not much actually as we still don't really have a clue what black holes actually are.\nThere are many questions to ask about the greenness of the black hole.. First, if the light is coming from the black hole itself then we actually don't have any black holes and everything we thought about them was wrong. \nScience is the art of guesswork based on what we already know. The term for this is called EMPIRICAL Science. Basically everything we are aware of is explained in this way.. When we make new laws or decided a black hole is a black hole, we are only guessing according to what we already know. \nIf you remember, people thought the world was flat, based on what they knew at that time. \nAnd the zeroth law of thermodynamics is called the zeroth because they had already come up with the first ,second and third before they realised they'd missed one..\nThe good thing about this is that essentially, this makes you just as smart as any of the top scientists in the world. Sadly, most of them would not share this point of view!!!!!
21830
"Dark" is not produced, per se...but it is an absence of light.  A black hole absorbs light...perhaps that is what you are looking for...\n\nLook at this website...it provides a quick overview of black holes and how they are created: \nhttp://www.damtp.cam.ac.uk/user/gr/public/bh_home.html\n\nAlso...to the person below me here...the clouds do not absorb light.  They block the sun's light and reflect it back to the atmosphere therefor cutting it off from our view.  However, some of the rays that come from the sun travel through the clouds, such as UV rays.  If the clouds absorbed light, we would see nothing during an overcast day.
527658
Ok for one anyone who has said light has mass is completely wrong. A black hole, as far as scientists know, is so massive that it infinitely distorts space time. Light is affected by space time. Think of it this way, you have sheet pulled tight then you drop a bowling ball on it but instead of just stretching it a finite amount, the divot in the sheet is infinite. Now if you were to roll a marble along the sheet it would go into that hole and not escape. Light is bent by the bends in space time so that when the light goes in it just follows the curvature of space time which "captures the light" and does not let it to flow back out.
498872
I think what you need to do is start looking at the picture in a different way.  \n\nYou're looking at the things that are THERE.  \n\nStart looking for what ISN'T THERE.  \n\nIt may be technically accurate to say that you can't see a black hole, because of the fact that our eyes register things that have light reflected off of them.  However, this doesn't change the fact that we can take a picture that displays the black hole, if only because of its nothingness.
31855
Like the posters above have said, the known laws of physics break down inside a black hole. Anything which passes inside the event horizon is no longer visible to anyone outside. What happens inside is just pure speculation, take your pick:\n\na. Matter, light and other trapped energy is compressed to incredible density\n\nb. Everything breaks down into its ultimately basic constituents (quarks, strings, whatever).\n\nc. Everything passes through a 'worm hole' to a 'white hole' somewhere else in the universe or in a different universe. A white hole (no one has ever observed one) is the opposite of a black hole, where everything is emitted out. It would appear like an incredible sourc of light.\n\nd. Black holes accumulate matter and energy, and ultimately the whole universe is concentrated into one single black hole. Suddenly "Let there be light", and it all explodes in another Big Bang to form a new universe. This is also called the theory of oscillating universes.