Black holes in space!?
113764
Black holes make White noise ... in all seriousness though, it's called "Black hole music" ...\n\nAstronomers were not surprised to find the supermassive black hole making a strong sub-bass sound. Though these greatest known matter sinks are by nature dark and invisible, they create bright and chaotic environments in which many forms of radiation -- from radio waves to visible light to X-rays -- have been recorded. These electromagnetic waves all travel at the speed of light.\n\nSound waves are similar, but they travel far more slowly and are more physical in nature. Sound you hear, for example, can be produced by the visible compression and expansion of a stereo speaker. The waves physically compress the stuff through which they move, be it air, water, or hot interstellar gas.\n\nOther studies have shown that the riotous activity around black holes -- where gas is accelerated to nearly light-speed -- produces many notes that are, all together, much like music. Collectively, the cosmos produce, scientists believe, a cacophonic symphony of inaudible tunes.\n\nMusical production appears to be ubiquitous in Nature. Scientists often call it flicker noise, and it has also been detected in the X-ray outputs of magnetic fields within our solar system. Even Earth hums its own tune. Musical analogies are found in everything from seascapes to brainwaves.
636436
As much as Sci-Fi wants it to be something exotic, I'm afraid there is no "other side" to a black hole.\n\nImagine an atom of normal matter. Most of it is empty space. But it takes a great deal of pressure to compress it --- more pressure than is usually available. But if we concnetrate enough mass, the gravitational force will be strong enough that the space can be compressed. Protons (positive charge) and electrons (negative charge) will be pressed together to form neutrons (neutral charge). This happens in the core of very large stars at the end of their life. Their last stage of fusion produced iron at the core. When enough iron exist at the core, it suddenly collapses as I've described here. It then forms what is called a neutron star. If it is oriented just right with respect to the earth, it also appears as a pulsar (Internet search: pulsar +star +radio).\n\nThe neutron star is extremely dense. But there is still a force exerted by the neutrons which keeps the compression from going any further. But what if the mass was large enough to overcome that force and squeeze it even smaller. It appears that once this happens, there is nothing left to stop the compression and it continues until the object takes up no space at all, which is why it is sometimes called a singularity. It is a point in space with a huge mass and therefore extremely strong gravity.\n\nAll objects exert a gravitational pull on other objects. And therefore all distort space and bend the path that light takes. But this new object is so compressed that near it, the gravity is so strong that the path of light beams are looped back and cannot leave the object. Since no light can escape from it and anything nearby falls into it and disappears, it is called a black hole.\n\nMoving out from the black hole, we finally find a distance where light can barely escape. The line that divides where light can and cannot escape from the black hole is called the event horizon. It is not a "surface" of the black hole as there is nothing there. It is merely the distance at which the gravity drops enough that light can escape. If you could build a camera and drop it though the event horizon, nothing would change as it went through. No difference would be recorded. However the radio transmission from the camera would cease as radio is the same as light, just a different frequency. Once the camera went past the event horizon, it would no longer be able to transmit the pictures to you. The radio waves would loop back and head into the black hole. There are also some strange things that happen to time as you cross the even horizon, but you can run an Internet search to find out more.\n\nBecause it has compressed to the point of not taking up space, conventional physics expressions for matter no longer make sense in this environment. You end up with fractions where the volume or distance is in the denominator (lower half of the fraction) and therefore the fraction has an infinite value --- which doesn't make sense. So we can't really project what is going on inside. But the idea that it is a portal to other dimensions is more SciFi than science. There are some esoteric theories that guess about such things, but they are guesses. \n\nHope this helps\n\nIf you are interested in astronomy, try \nhttp://groups.yahoo.com/group/lunar-observing/\n\nChuck
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..
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!
273528
The defining factor of a black hole is that the escape velocity is higher than the speed of light.  This is a function of density and not total mass.  It's possible to have very small black holes.  They can even have masses smaller than that of an atom.  The LHC at CERN, which is expected to come online in 2007, may be capable of producing such microsingularities.  \n\nAs for our universe being a black hole...  from inside it's certainly not.  But, from "outside", if you can define such a thing, maybe it does appear as such, since light cannot escape out universe.  This assumes, however, that there is an outside from which this can be considered, and there's no proof, and perhaps no way to prove, whether or not there is.
575553
Nope.  Whoever told you this has been watching too much science fiction.\n\nBlack holes are just collapsed stars, and their gravity is no bigger than any other star (except to things that are very close to it).  There are enormous black holes at the center of galaxies, but these don't pose a threat to the majority of the galaxy ... and the earth is way out near the edge of our galaxy.  And there is no black hole even theorized that is big enough to swallow entire galaxies.
72214
Black holes almost certainly exist. Wormholes almost certainly do not.
695407
Excellent question! It's got many of us thinking.\n\nThe nature of black holes is such that not everything cannot escape from it, contrary to popular belief.\n\nBlack holes will emit high energy photons in a gamma ray burst.\n\nDavid Cline at UCLA suggests they are the detonation of microscopic black holes formed in the Big Bang, which most astronomers believe was the beginning of the universe. If the idea is right, billions and billions of relatively nearby, primordial black holes are just waiting to explode. \n\nSome may exist just beyond the orbit of Pluto, based on the math.\n\nThere was a recent article in New Scientist regarding a similar topic to this. Another good point for research would be NASA's Chandra telescope pages.\n\nI'll certainly be discussing this one with my team!
515904
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
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.
1151473
No, because a black hole is a collapsed star, and the closest star to us, besides the sun, is thousands of light years away. They also suck in EVERYTHING including light and destroys it.
533667
Black holes are not holes at all.  These do not have any bearing on other universes.  They are just extremely massive objects that have collapsed within the Schwarschild radius and into a single point, which creates an area in space in which light could not escape if it gets so close.  \n\nAs for other universes, according to string theory we exist in a 3 dimensional subspace of a 13 dimensional universe.  Since we only occupy 3 dimensions, there could be other multi-dimensional subspaces which could affect our universe.  In fact, one theory of the big bang is that gravity from another universe and our own had caused them to touch, which concentrated energy in a single region, since energy is subject to gravity.  After this touching, the two universes went apart, and caused this energy to expand and 'cool' into matter that we know as our own universe.
274083
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.
238288
Black holes, Yes. Aliens, No.
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.
663273
We have found black holes in the universe but never a "White hole". A white hole is a concept that arises out of tweaking Einstein's equation. Theoretically a white hole would be connected to a black hole through space time and it would spew out all the matter and energy that the black hole sucked in. The issue is that the white hole emerged from looking at einsteins equations in a vacuum with no matter. Mathematically this connection would be highly unstable and would most likely disappear as soon as it formed. But mathematically this situation could happen. It has never been found though. I hope that helped
1055719
Ok, first things first.  This situation cannot occur.  Such a string does not exist and probably cannot exist.\n\nA black hole is actually not a "hole" so to speak.  It is a super-dense core.  The denser an object is, the stronger the force of gravity that this object exerts on all objects around them.  That means that even you or I exert gravity on everything around us.  However, our own gravititational force is so weak that we don't even perceive it.\n\nNo one that we know of has gone near a black hole.  The nearest known black hole is 1600 light-years away.  One light year is approximately 6 trillion miles.  So the nearest black hole (that we know of) is approximately 1600 times 6 trillion miles away, or 9.6 quadrillion miles away.\n\nAnyway, I don't want to complicate it too much.  This is stuff you would learn in a high school or college physics class, and my guess is that you have not taken such a course yet in your life.