Would we always know when we reached a black hole's event horizon by noticing its high density? Explain.?
971309
The best way to know that you've moved inside the event horizon of a black hole is by finding that you can no longer communicate with the rest of the universe. For instance, if you were in a probe launched by a nearby mother ship and passed inside the event horizon, all radio contact with the mother ship would be totally lost because nothing can escape from inside the event horizon.
286980
Black holes do not give off any light, so they can't be seen directly.\n\nWhat we can see is the EFFECT of the black hole.  \n\nOne effect is caused by the fact that massive objects will bend light as it passes them - this is called "Gravitational Lensing".  \n\nAs a result, if we detect light from a distant star that is distorted in the specific pattern of gravitational lensing, we can deduce that there is a dark, massive object at the center of the distortion.\n\nAnother effect is produced when matter that is pulled into the black hole.  Once matter or light gets closer to a black hole than the critical distance (the "event horizon") it vanishes into the black hole and is never seen again.  But, matter NEAR the black hole that is falling into it will give off light or other radiation as it is destroyed by the black holes gravitational force.  This radiation includes bursts of X-rays, which we can detect.\n\nThe first black hole that was detected is called Cygnus X-1 (it is an X-ray source in the constellation of Cygnus, the swan).
784181
"...Does the black hole continue to increase in mass and increase the gravitational affect?..."\nWe haven't been studying black holes long enough yet to determine if their mass does increase from all the material being drawn in. Theoretically it would.\n\n"...does all that stuff get shot out in another direction?..."\nExactly what happens to material that disappears beyond the event horizon of black holes isn't known for sure because there's no way science can observe what goes on there. A few speculations persist about so-called  'white holes,' the drain of black holes where everything re-appears in another universe or dimension.\n\n"...Do black holes ever die? And if so, what happens to them?..."\nAgain, science doesn't know because the observational evidence just isn't there. However, Stephen Hawking has developed a workable theory showing that over great lengths of time black holes can actually radiate some of their energy and in time would evaporate.
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.
486631
Assuming this is possible the end positioned inside the event horizon would be broken down into it's individual atoms and would cease to exist.  However some scientists (me being one of them) think black holes are only one end of a worm hole and that when you reach the event horizon you are expelled out of a white hole into another universe.  Think of a white hole as the polar opposite of a black hole, instead of consuming every thing it expels everything
118180
This question is meaningless if you think how we came to use the term.\nScientists observed irregularities in motion of celestial bodies that defied known theories. After reviewing the theories they concluded that the theories are correct and there must be something outthere that caused those irregularities. They calculated the mass and energy of such bodies and they found they gravitational pull is so extreme that to escape their pull (from nearby vicinity) matter must exceed the speed of light.\nThese regions in space were given the name of black holes (since light itself cannot escape the pull, their are invisible). Their existance can be noticed by matter being attracted to blank spots (nothing is visible there, not even starlight). 'Black hole' is a term used to describe an existing celestial body, therefore no 'proof' is needed.
758608
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.
284539
When we discover what happens in a singularity (the center of a black hole) we'll be a step closer to a grand unified \ntheory.
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.
1160171
its a MATHIMATICAL prediction that warmholes (or "shortcuts" in spacetime... so you fly into black hole and boom you're in another part of the universe or another universe all together) exists\n\nUnfortunatly this prediction bares no physical merrit as neither the black hole is capable of "letting things fall through" nor is a "whitehole" capable of existing for more then one instance (aside the fact that it cannot form, period)\n\nThe mathematical model is beautiful though, if you know much math I suggest you check it out.!
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!!!!!
6001
yes!!\n\nBlack holes are predictions of Albert Einstein's theory of general relativity. In particular, they occur in the Schwarzschild metric, one of the earliest and simplest solutions to Einstein's equations, found by Karl Schwarzschild in 1915. This solution describes the curvature of spacetime in the vicinity of a static and spherically symmetric object, where the metric is\n\n    ds^2 = - c^2 &#92;left( 1 - {2Gm &#92;over c^2 r} &#92;right) dt^2 + &#92;left( 1 - {2Gm &#92;over c^2 r} &#92;right)^{-1} dr^2 + r^2 d&#92;Omega^2,\n\nwhere d&#92;Omega^2 = d&#92;theta^2 + &#92;sin^2&#92;theta&#92;; d&#92;phi^2 is a standard element of solid angle.\n\nAccording to Schwarzschild's solution, a gravitating object will collapse into a black hole if its radius is smaller than a characteristic distance, known as the Schwarzschild radius. Below this radius, spacetime is so strongly curved that any light ray emitted in this region, regardless of the direction in which it is emitted, will travel towards the center of the system. Because relativity forbids anything from travelling faster than light, anything below the Schwarzschild radius – including the constituent particles of the gravitating object – will collapse into the center. A gravitational singularity, a region of theoretically infinite density, forms at this point. Because not even light can escape from within the Schwarzschild radius, a classical black hole would truly appear black.\n\nThe Schwarzschild radius is given by\n\n    r_s = {2&#92;,Gm &#92;over c^2}\n\nwhere G is the gravitational constant, m is the mass of the object, and c is the speed of light. For an object with the mass of the Earth, the Schwarzschild radius is a mere 9 millimeters — about the size of a marble.\n\nThe mean density inside the Schwarzschild radius decreases as the mass of the black hole increases, so while an earth-mass black hole would have a density of 2 × 1030 kg/m3, a supermassive black hole of 109 solar masses has a density of around 20 kg/m3, less than water! The mean density is given by\n\n    &#92;rho=&#92;frac{3&#92;,c^6}{32&#92;pi m^2G^3}\n\nSince the Earth has a mean radius of 6371 km, its volume would have to be reduced 4 × 1026 times to collapse into a black hole. For an object with the mass of the Sun, the Schwarzschild radius is approximately 3 km, much smaller than the Sun's current radius of about 700,000 km. It is also significantly smaller than the radius to which the Sun will ultimately shrink after exhausting its nuclear fuel, which is several thousand kilometers. More massive stars can collapse into black holes at the end of their lifetimes.\n\nMore general black holes are also predicted by other solutions to Einstein's equations, such as the Kerr metric for a rotating black hole, which possesses a ring singularity. Then we have the Reissner-Nordström metric for charged black holes. Last the Kerr-Newman metric is for the case of a charged and rotating black hole.\n\nThere is also the Black Hole Entropy formula:\n\nS = &#92;frac{Akc^3}{4&#92;hbar G}\n\nWhere A is the area of the event horizon of the black hole, &#92;hbar is Dirac's constant (the "reduced Planck constant"), k is the Boltzmann constant, G is the gravitational constant, c is the speed of light and S is the entropy.
849237
There's most likely not an 'other side'.  A black hole is a bunch of matter that's been compressed down into a singularity, or an extremely dense spot.  More stuff falling into the hole isn't going anywhere; it's just contributing to the density of the black hole itself.
473814
General 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.
326157
I have a feeling you mean "when" not where?\n\nThe concept of a body so massive that not even light could escape it was put forward by the English geologist John Michell in a 1783 paper sent to the Royal Society.\n\nBefore the term black hole was created (i believe in the late 60's) reference to this kind of object was called a black star in the origional 60's star trek series.
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
437322
The mathematics of black holes shows that they might be able to transport you to another region of space or possibly another universe. However, the mathematics also shows that the connection only lasts for a fraction of a second at a time, and that the link to other universes depends on a specific set of conditions which scientists do not believe to exist. Even if it were likely, however, the strong gravity field of the black hole tears apart any material falling into the hole so it would not come out the other end of the Black Hole looking anything like how it went in, so in other words you would  have to really want to make this discovery because you’re going to die trying.