How many things disappeared into a black hole that we know about?
373282
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..
1079881
The more mass you add to a black hole, the BIGGER if gets. The only way to make a black hole disappear (according to Stephen Hawkins) is to leave it alone for a very very long time. It will very slowly evaporate if you don't add more mass to it.
943441
Hey, I'm gonna give you the truth instead of spilling abunch of theories at you. \n\nNobody knows. Black holes and everything related to them are one of the most mysterious things out there. Not that we REALLY know much else about whats going on out there. Everything so far is based on theories drawn from basic laws of physics. \n\nWho knows, maybe you and I will live to see the day they can tell us it is a fact. I hope so, there are many questions I would like to know the answers to. =)\n\nEDIT: Bill, I believe the theory I last heard on that is as follows: \n\nOnce a black hole has nothing else to 'feed' on it will collapse. Scientist recently believed that the end of the universe was gonna be in a black hole, a super massive black hole, that was thought to be in the location of where the Big Bang took place. They assumed that the universe would quit expanding and retract on itself. They recently found out that they were COMPLETELY wrong in that assumption. In fact, the universe is expanding at a faster rate then it originally was. Their new theory is that the universe will continue to expand, eventually breaking down everything in the universe (sun, moons, and planets encluded). True? Couldn't tell you honestly, they may come up with a different theory tomorrow.
775784
Black holes as mentioned above are a singularity.  Nobody really knows what happens once you cross the event horizon ( the edge of the black hole).  These are very strange events in that they pull everything including light towards them, which contradicts Newtons second law with mass being proportional inversely proportional to mass ( as light has no mass) and Einstein's theory of relativity and the conservation of mass and energy.  All theory we have breaks down when we encounter black holes.\n\nAn interesting theory is that black holes are a link to another universe, matter passing through a black hole and appearing through a white hole in another universe.  This theory has the assumption that there is more than one universe and that they are all linked.  Stephen Hawking's "A Brief history of time" gives many interesting insights.  \n\nHe has recently changed some of his views however with a new theory that a Universe is created by the bumping of one universe into another with black holes becoming the remanents of the reaction, and thus there is no begining or end to time.  He is publishing his ideas soon.  In short however nobody really knows what happens in a black hole.
224610
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.
1117575
It is precisely that the density of a black hole is beyond the scope of reality that makes a black hole what it is - a singularity. In mathematics, a singularity is a point at which an equation cannot be solved. A simple example is 1/x, which is undefined at 0. In a black hole, the laws of physics have no solution.\n\nThe atomic bomb has nothing to do with this. Radioactive material like plutonium will explode in a runaway chain reaction if sufficient mass is brought together. (An explosive mass of radioactive material is called a prompt critical mass.) This only works with highly radioactive materials and involves no compression, whereas anything will form a black hole if sufficiently compressed. Compressing matter to this level is far beyond our current capabilities, however; it takes the collapse of a massive star to make a black hole.
468852
A black hole, by definition, doesn't emit light; photons can enter the event horizon of a black hole, but cannot emerge from it. If you can't see a black hole, then how do you know it's there?? In order to detect a black hole, you have to be devious and use indirect methods. \nThe method of detecting dark objects by noting their gravitational effect on luminous objects is a very old one. \n\nThe planet Neptune was first discovered from its gravitational effect on the planet Uranus. \nThe white dwarf Sirius B was first discovered from its gravitational effect on the star Sirius A. \nA black hole can be discovered from its gravitational effect on luminous matter (stars and/or hot gas).\n\nIf a black hole exists in a close binary system, it can be detected indirectly. Gas ripped from the companion star will spiral in toward the black hole. As it does so, it is heated up (by tidal heating, and by friction as it rubs against neighboring gas). The hot gas emits X-rays as it undergoes its death spiral to the event horizon. (Once it's inside the event horizon, we don't see the gas any more, but it's highly visible as long as it's outside.) If you are hunting for black holes, it's good to start by looking for binary star systems which are also strong X-ray sources. \n\nAbout a dozen other black hole candidates, with masses up to 10 solar masses or so, have been found in binary star systems within our galaxy. (We don't expect too many black hole stellar remnants, given the scarcity of the extremely massive stars which are their precursors.) \nAn interesting recent development in astronomy is that supermassive black holes (that is, black holes more than a million times the mass of the Sun) are found at the centers of many galaxies. Our own galaxy, for instance, has a black hole with mass 2.6 million Msun at its center, 8000 parsecs away from us. Our own galactic black hole is actually fairly wimpy. The Andromeda Galaxy, 700,000 parsecs away, has a black hole with a mass of 30 million Msun. \n\nHow do you go about hunting such supermassive black holes? As usual, you go about it indirectly, by looking at the orbital motion of gas and stars near the centers of galaxies. For instance, the observation of stars near the center of our own galaxy has revealed that they are orbiting a massive object with M = 2.6 million Msun. The closest star to this massive object comes within 17 light-hours (120 A.U.) of its center. The only plausible way to cram 2.6 million solar masses of stuff into a sphere 120 A.U. in radius is to make it all into a single big black hole. (For instance, if you tried to make a cluster of a million neutron stars 120 A.U. in radius, the collisions between neutron stars would make them all merge into a single big black hole within a few hundred thousand years.)
440519
I believe that everything (not even light can escape; that's how strong the gravity of a black hole is) that is sucked into a black hole turns into "singularity" which has an unimaginable mass.
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
712417
"Singularity\nAt the center of the black hole, well inside the event horizon, general relativity predicts a singularity, a place where the curvature of spacetime becomes infinite and gravitational forces become infinitely strong.\n\nIt is expected that future refinements or generalisations of general relativity (in particular quantum gravity) will change what is thought about the nature of black hole interiors. Most theorists interpret the mathematical singularity of the equations as indicating that the current theory is not complete, and that new phenomena must come into play as one approaches the singularity.[15]\n\nThe cosmic censorship hypothesis asserts that there are no naked singularities in general relativity. This hypothesis is that every singularity is hidden behind an event horizon and cannot be probed. Whether this hypothesis is true remains an active area of theoretical research"
301206
The Satellite Situation Report from NASA's Goddard Space Flight Center. Dated September, 1997, the report counts almost 25,000 man-made objects: 8681 currently in orbit, and over 16,000 objects in a state of decay. Not every single satellite is included, since some are too small or too far away from home to be detected.\n\nRussia leads the list in decayed objects (with a debris count close to 10,000) and comes in a close second (3897) to the United States (4018) for currently orbiting objects. Keep in mind that these figures are already a few years old.
904101
In 1975, Stephen Hawking and Jacob Bekenstein showed that black holes can slowly radiate away energy (Hawking radiation), which created a paradox, because we mostly expect that the Hawking radiation to be independent of the material entering the black hole. However, if the material entering the black hole were in a pure quantum state, then the transformation of that pure state into the mixed state of Hawking radiation imply that the  information in the original quantum state has been destroyed. This implies that we can not be sure of anything in the Universe, because the information about that something may be incomplete or have been lost completely.\n\nToday, the predominant belief among physicists is that information is preserved and that Hawking radiation is not precisely thermal but receives quantum corrections. Other possibilities include the information being contained in a Planckian remnant left over at the end of Hawking radiation or a modification of the laws of quantum mechanics to allow for non-unitary time evolution.\n\nIn July 2004 Stephen Hawking himself announced a theory stating that quantum perturbations of the event horizon could allow information to escape from a black hole, and thus resolve the information paradox. However, the full details of his theory is still unpublished, so the jury is still out.
936416
you should see the nova on blackholes, it was on last week\n\napprently only to much can actually get to the center at a time, and most matter/energy gets bounced around within the event horizon, never to escape, but not actually getting all the way in\n\nand anyway blackhole emit particles of hawking radiation and would eventually expell there mass and kinda evaporate away\n\nand if one black hole had the whole universe in it, sounds prime for  big bang to me
261464
Additional info: I've talked to Holger Bech, one of the three founding fathers and Danish, and not even he believes in the theory. Basically, this is due to the String Theory postulating the existence of 9 dimensions. We can see that this is pretty far from the case, with there only being 3 physical dimensions and time, equaling 4. Furthermore, S.T. postulates that almost 300 of a specific grouping of particles exist. Experimental testing estimates that only 16 exist.
268153
Three cosmic enigmas, one audacious answer\n09 March 2006 \nExclusive from New Scientist Print Edition \nZeeya Merali \n\n \n\n \n\n  \nDARK energy and dark matter, two of the greatest mysteries confronting physicists, may be two sides of the same coin. A new and as yet undiscovered kind of star could explain both phenomena and, in turn, remove black holes from the lexicon of cosmology.\n\nThe audacious idea comes from George Chapline, a physicist at Lawrence Livermore National Laboratory in California, and Nobel laureate Robert Laughlin of Stanford University and their colleagues. Last week at the 22nd Pacific Coast Gravity Meeting in Santa Barbara, California, Chapline suggested that the objects that till now have been thought of as black holes could in fact be dead stars that form as a result of an obscure quantum phenomenon. These stars could explain both dark energy and dark matter.\n\nThis radical suggestion would get round some fundamental problems posed by the existence of black holes. One such problem arises from the idea that once matter crosses a black hole's event horizon - the point beyond which not even light can escape - it will be destroyed by the space-time "singularity" at the centre of the black hole. Because information about the matter is lost forever, this conflicts with the laws of quantum mechanics, which state that information can never disappear from the universe.\n\nAnother problem is that light from an object falling into a black hole is stretched so dramatically by the immense gravity there that observers outside will see time freeze: the object will appear to sit at the event horizon for ever. This freezing of time also violates quantum mechanics. "People have been vaguely uncomfortable about these problems for a while, but they figured they'd get solved someday," says Chapline. "But that hasn't happened and I'm sure when historians look back, they'll wonder why people didn't question these contradictions."\n\n“People have been uneasy about these problems with black holes, but figured they'd get solved. That hasn't happened”While looking for ways to avoid these physical paradoxes, Chapline and Laughlin found some answers in an unrelated phenomenon: the bizarre behaviour of superconducting crystals as they go through something called "quantum critical phase transition" (New Scientist, 28 January, p 40). During this transition, the spin of the electrons in the crystals is predicted to fluctuate wildly, but this prediction is not borne out by observation. Instead, the fluctuations appear to slow down, and even become still, as if time itself has slowed down.\n\n"That was when we had our epiphany," Chapline says. He and Laughlin realised that if a quantum critical phase transition happened on the surface of a star, it would slow down time and the surface would behave just like a black hole's event horizon. Quantum mechanics would not be violated because in this scenario time would never freeze entirely. "We start with effects actually seen in the lab, which I think gives it more credibility than black holes," says Chapline.\n\nWith this idea in mind, they - along with Emil Mottola at the Los Alamos National Laboratory in New Mexico, Pawel Mazur of the University of South Carolina in Columbia and colleagues - analysed the collapse of massive stars in a way that did not allow any violation of quantum mechanics. Sure enough, in place of black holes their analysis predicts a phase transition that creates a thin quantum critical shell. The size of this shell is determined by the star's mass and, crucially, does not contain a space-time singularity. Instead, the shell contains a vacuum, just like the energy-containing vacuum of free space. As the star's mass collapses through the shell, it is converted to energy that contributes to the energy of the vacuum.\n\nThe team's calculations show that the
794668
Well, black holes are mysterious simply because they are regions where light itself cannot escape!  If you go by general relativity black holes are singularities where space and time lose their meaning in the rational sense!  As for black holes leading to some location, most likely that is not the case.  Such an object is a wormhole, which is a theoretical solution to Einstein's field equations like black holes are.  But, wormholes have not been observed in nature and they are unstable to the point where if even a tiny amount of mass enters the wormhole it will collapse it and destroy the matter before it ever gets to the other side!  So, that being true a black hole has no opening somewhere else, because if it did it would collapse the same way.  However, Stephen Hawking showed that black holes do dissipate over many billions of years because of quantum tunneling.  Turns out some matter/energy actually gets out of the black hole!  So, we still have alot to learn about the nature of black holes, because we still have to learn alot about gravity!
1122271
A black hole does not necessarily pull in everything in the universe. It's gravitational field is no different from any other object of the same mass, until you get very close.\n\nAccording to Stephen Hawking, black holes will evaporate over time. However, a black hole the mass of the Sun would take many times the current age of the universe to disappear. So the billion-solar-mass black holes at the centers of giant elliptical galaxies will probably still be around when everything in the universe has gone cold.