what is the truth about black holes?
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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
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A black hole is a place where the escape velocity is greater then the speed of light because the object's gravity is so strong.  Since nothing is known that can go faster then the speed of light, anything falling into a black hole can never get out, hence the name "black hole."  What happens inside a black hole is not known.  The center of a black hole is theorized to be a singularity because it is a point where all the black hole's mass is squeezed to a point of infinite density.  We really don't know for sure what happens in a black hole because our current theories are not complete, and the fact that no information can ever leave a black hole.  While nothing can escape into a black hole, we can detect them because as things fall into them, they heat up and give off x-rays before they make the plunge.\n\nTwo types of black holes are known to exist.  One is formed when an extremely massive star dies, and it's core is so massive and small that it collapses under its own gravity to become a black hole.  Another type are called "supermassive black holes" which seem to exist in the center of every galaxy (that means our own too).  How or why these black holes formed nobody really knows.  It probably goes back to how galaxies formed in the first place, although we don't know that either.
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*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.
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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.
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We haven't actually had a black hole close enough to experiment with, at least not that we know about--although there are theories about dryers having a black hole that eats socks, see earlier response!!--so most of the work on black holes is done with theory, prediciting what a black hole might do, and then seeing if something out there is doing it.\n\nNow, the best data seems to be based on the orbital velocities of stars in galaxies: the velocity distributions demand a truly massive central mass in a lot of the galaxies, one that is best viewed as a black hole.\n\nSome very nice data exists with observations of events predicted to happen with "near misses" with black holes--particles that get into the titanic gravity well of the black hole, but decay into two particles, one escaping the black hole.\n\nBut no one has actually seen a black hole do anything, directly..
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The current scientific theory holds that black holes are formed when stars of sufficient mass (about 3x the mass of our Sun) reach the end of their life and collapse down into a singularity, which is, in essence, an infinitely small point with a huge amount of gravity - gravity so powerful that not even light can escape it's pull if it gets too close. It is also thought that black holes can be formed from smaller masses if external energy/pressure is exerted to squeeze the mass into a singularity.\nNot sure if there's any direct experimental evidence of creation, but there is evidence that they exist. Cosmologists use several different methods to detect blacks holes, such as by looking for light being bent and/or disappearing as it travels from remote stars towards us, and also by looking for bursts of x-rays that are given off as matter is sucked into the back hole and destroyed.\nFun fact: current evidence and theory suggests that the center of the Milky Way is a giant black hole that was formed as the densly packed stars in the center collapsed and sucked each other in.
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yes, black holes really exist.  there is enough evidence for their existence that almost all astronomers would accept that they do.\n\nread this page:\nhttp://en.wikipedia.org/wiki/Black_hole
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The writings of Stephen Hawking should answer most of your questions about black holes. Show people that you have learned from previous questions that you have asked about black holes by including information in the question details, or why it is relevant.\n\nTry choosing a best answer yourself, instead of leaving it to a vote. This will mean actually reading the answers given. You can learn a thing or two.
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No.  A black hole is an immensely dense object, like taking all the matter in our solar system plus more, and condensing it to the size of a pea or so.  The moment we could "create" one, the entire earth would be "sucked into" it.
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a black hole is an area of space-time with a gravitational field so intense that its escape velocity is equal to or exceeds the speed of light.
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Although black holes are not directly detectable, there is much indirect evidence of their existance such as the movement of other objects.\n\nGravity is not a simple phenomenon and cannot "escape" from anything. It is a property of space-time itself.
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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.
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A black hole is just like any other star or planet. \n\nThe larger the body's mass, the greater its gravity pull. That's why the lunar astronauts could bounce along on the moons surface, the gravity there is much lower than on Earth as the moon is much smaller.\n\nOur sun's gravity is enough to keep all the planets in their orbits.\n\nA black hole was a very large star, with high gravity, so high that when it ran out of fuel, it collapsed in on itself. Because the material making up this star is now concentrated down to such a degree that the gravity near it is so strong even light cannot escape, we call it a black hole.\n\nIf something is sucked into it, the mater does not go anywhere, it just gets squashed into the same place as all the other material making up the black hole.
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Most people *don't* believe galaxies are black holes.  A black hole is a region of space from which nothing can escape, even light.  \n\nSince you can't see a black hole (that light that isn't escaping), one has to rely on indirect evidence.  \n\n If you've found a large mass concentrated in a small volume, and if the mass is dark, then it's a good guess that there's a black hole there.  \n\nIt'll be quite some time before we can get "hard evidence" of a black hole.  We don't even have "hard evidence" that those are stars; it's just indirect evidence.
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Things that enter a black hole do not "implode," and black holes and the big bang are two uttern non-connected things.\n\nshort answer day!
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A black hole is a concentration of mass great enough that the force of gravity prevents anything past its event horizon from coming out of it. A black hole may be a huge star more than 6 times the mass of sun or other huge concentrations of matter.\n\nIt has a gravitational field so strong that nothing even light,the fastest thing known to humans cant escape from its garvitational power. for more try http://en.wikipedia.org/wiki/Black_hole
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unless this is a "zen" question, it doesn't "go" anywhere.  A black hole is a former star that has died and collapsed in upon itself and had its mass "infinitely" compressed into a tiny tiny volume.