What are facts about black holes?

Answer 1

• There are currently 14 known Black holes.
• The closest black hole to earth is cynus x-1 located about 8000 light years away.
• All black holes emit radiation.
• A black hole is actually colder than empty space.
• A black hole smaller than Mercury will evaporate due to Hawking Radiation.
• Time appears to stop at the event horizon for an external viewer, but does not actually stop, local time continues: the speed of light time contraction - a space ship flying away from earth at a large % of the speed of light apparently has time running slower than that of earth, but to the ship, earth is moving faster. The same thing applies for the black hole - gravity is so heavy there that it does the same time contracting...
• Following conventional black hole theory, there is no tunnel at the middle of the black hole, just a massive amount of matter compressed infinitely: we can't go through to another universe but we can become very small piles of tomato aspic.
• The sucking force of the black hole is so powerful that it even light can't escape.
• Black holes are 10 to 15 times as massive than our sun.
• Black holes can only suck matter and other items in their horizon (area) only. If the matter is out of that horizon then, it won't get sucked in.
• As you approach a black hole, the velocity require to fly away -- the 'escape velocity' -- increases. The event horizon is the point at which the escape velocity exceeds the speed of light. Beyond this point, even light cannot escape.
• Anything that "falls" into a black hole will never return.
• If you compressed the mass of the earth down to the size of a ping pong ball you would have a black hole.
• If the earth was a black hole it would still go around the sun and the moon would still go around the earth as if nothing has happened.

• Although black holes have a strong gravitational force, they may only suck up what crosses their event horizons, and, therefore, are not capable of absorbing the whole universe.
• In theory, any matter can become black holes, as long as they are compressed to zero volume and thus, yielding infinite density. However, only the largest of stars have cores capable with the gravitational force to compress the star to the Schwarzschild radius. Most others stars without this gravitational force end up as neutron stars and white dwarfs.
• Black holes can suck up other black holes when they come in close proximity. Usually the larger one will suck up the smaller one. Depending on the size of the matter that is making up the black holes, the size of the black hole created will differ. Direct collisions between black holes are rare, as black holes are very small for their mass. Black holes may also merge.
• The center of a black hole, the singularity, is the point where the laws of physics break down. These singularities are hidden, or 'clothed' by the black hole, so that the effects of the breakdown cannot be observed by people outside.
• At the center of a black hole, spacetime has infinite curvature and matter is crushed to infinite density under the pull of 'infinite' gravity. At a singularity, space and time cease to exist as we know them. The laws of physics as we know them break down at a singularity, thus, making it impossible to envision something with zero volume and infinite density, such qualities of a black hole.
• By using the correct equations for motion, it can be predicted that near a black hole, an object on a radial path will have a velocity approaching the speed of light. This occurs as the object approaches the event horizon.
• Small black holes will evaporate, but big ones will continue to suck in matter and energy, growing ever more massive.
• On February 1997, the Hubble Space Telescope had a new instrument installed. Called the Space Telescope Imaging Spectrograph (STIS), this equipment is the main black hole seeker on the telescope. A spectrograph splits any incoming light using prisms and diffraction gratings into a rainbow. The STIS can measure ultraviolet, visible, and near-infrared wavelengths, allowing it to capture a wide range of places at once. The placement and intensity of the spectrum gives indispensable information to scientists. Every spectrum can be analyzed to find out the speed of which stars and gas swirl at a certain location. From this information, the mass of the object that the stars are orbiting can be found. A massive central object is found if the stars swirl quickly.

Answer 2

Amazing things! Some of them have been around since the beginning of the universe. IF you can get a probe near enough to it, you'll see things from millions even billions of years ago orbiting and being sucked into the black hole. You'll also be able to confirm that the theories of Everything work. You can also show how relativistic time works: as you approach the black hole, the time you experience slows in comparison with a third person viewer. They also make great garbage disposals - radioactive material will not come out, neither will plastic, or diapers or mercury poisoned fish!

Answer 3

by reversing the equations created by roger penrose on black holes, hawking discovered that a singularity which lies at the centre of black hole could be the very source of everything in the universe i.e a singularity would have been the source of the big bang.

he also discovered that black holes take in large amounts of anti matter particles from 'empty space'. these particles have a negative mass and so decrease the mass of a black hole, in doing so the black hole eventually has too little mass to sustain itself and dies in a violent explosion.

he also showed that black holes would be surrounded by a belt of radiation due to the situation created when taking in anti matter particles but leaving their counterparts behind.

Answer 4

What we can learn from black holes includes new physical theory and validation of existing theory. For example, General Relativity predicted the existence of black holes; from astronomical observation we later obtained verification of their existence and thus validation of the theory, which aligns well with the scientific process. We can also determine the nature of the universe as a whole and clues about its age and fate. Current theories about stellar evolution are ratified by data gathered on black holes; development of certain areas in particle physics and quantum mechanics could be verified - for example experimental verification of the existence of Hawking radiation; currently a search is in progress for gamma bursts predicted at the end of life of some black holes. In a broad philosophical sense, mysteries can drive scientific discovery; some unexplained aspects of black holes continue to drive research and discovery. Perhaps even a more complete picture of unification of forces including a better description of principles of quantum gravity, or the nature of exotic matter present in the black hole singularity could be found.

Answer 5

Black holes are regions in space with gravity so strong that nothing, not even light, can escape from them. They form when massive stars collapse in on themselves. Black holes are not visible directly, but their presence can be detected by the effect they have on nearby stars and gas.

Answer 6

it's unique because it can suck in any thing it can reach. it can even suck in stars, but not the sun. (there is also a such thing as a spinning black hole, and it sucks up more stuff!)

Answer 7

What the Hubble space telescope can tell us about black holes is there location there size and how fast it is spinning.