what is black hole and how it was found?

Answer 1

A black hole is when there is something with so much gravity that it actually "pulls" light into it. Since we see and sense things by the light that comes from it, and black holes have no light coming from it (it is all "sucked" in by the huge gravity) it appears black.

Since the strength of an object's gravity depends on its mass, an object with enough gravitational force to form a black hole has to be very massive. But the force of gravity also depends on how far away it is: The further away an object is, the LESS gravity it has. Therefore, the object also has to be small so things can get close to experience the highest gravity.

They are formed from very large stars. Larger stars burn their fuel much faster than smaller ones. These large stars burn so hot they readily burn their hydrogen into helium. They also burn their helium into oxygen and carbon. When the Helium starts to get used up, they begin fusing the oxygen into neon and eventually fusing the remaining core material into iron. When the core becomes mostly iron, there is no further fusion possible, and the fusion reactions suddenly stop.

The nuclear reaction creates an outwards force that counters the crushing gravity of the star. When the fusion reactions stop, there is no further outward pressure force; the gravitational force of the huge mass collapses the star. It then rebounds back in a huge shockwave that blows the outer layers of the star violently away. This enormous, very brilliant explosion is called a supernova.

What is left in the center of the star is very dense and the mass of it starts to colapse it in on itself by it's own gravity (like making a ball of aluminum foil and then squashing it hader and harder to make it smaller and smaller). If what is left in this center is bigger than about 1.4 times the mass of our sun, it will crush so small and have so much mass that its gravity will be strong enough to start "sucking in" the light around it and a black hole will be formed.

Black holes are "found" by the effects they have on other things. First, there is a empty spot. Nothing can be found there. Second, a black hole has so much gravitation force that things not near enough to it to be sucked in are still pulled and altered by this gravity. Astronomers can see the deflection and bending of things and know that there is something with a large gravity there; they can't "see" a normal star, so postulate it must be a black hole.

That's it in the basics without going into details or all the scientific stuff.

Answer 2

A black hole is an object in space with gravity so strong that not even light can pull away from it. Because light can't escape a black hole it can't be seen, hence the name 'black' hole.

Black holes have been found in two ways --
1. Intense x-radiation is generated by all the matter being sucked into the black hole and we can easily spot those radiation fields;
2. If a black hole is located fairly near to another object we can see, like a star, the star will wobble as it moves through space due to the gravity of the black hole.

Answer 3

A black hole is a region of space in which the gravitational field is so powerful that nothing can escape after having fallen past the event horizon. The name comes from the fact that even electromagnetic radiation (e.g. light) is unable to escape, rendering the interior invisible. However, black holes can be detected if they interact with matter outside the event horizon, for example by drawing in gas from an orbiting star. The gas spirals inward, heating up to very high temperatures and emitting large amounts of radiation in the process.[2][3][4]

While the idea of an object with gravity strong enough to prevent light from escaping was proposed in the 18th century, black holes, as presently understood, are described by Einstein's theory of general relativity, developed in 1916. This theory predicts that when a large enough amount of mass is present within a sufficiently small region of space, all paths through space are warped inwards towards the center of the volume, forcing all matter and radiation to fall inward.

While general relativity describes a black hole as a region of empty space with a pointlike singularity at the center and an event horizon at the outer edge, the description changes when the effects of quantum mechanics are taken into account. Research on this subject indicates that, rather than holding captured matter forever, black holes may slowly leak a form of thermal energy called Hawking radiation.[5][6][7] However, the final, correct description of black holes, requiring a theory of quantum gravity, is unknown.Black holes can have any mass. Since the gravitational force of a body on itself, at the surface of a body of any shape, increases in inverse proportion to its characteristic lengthscale squared (as volume-2/3 ), an object of any shape and mass that is sufficiently compressed will collapse under its own gravity and form a black hole. However, when black holes form naturally, only a few mass ranges are realistic. Its impossible to escape from a black hole because of its mass.

A black hole was discovered because of its radiation. Radiation is measured by an electromagnetic device

Answer 4

oki space is like a blanket. a big never ending black blanket. a black hole is like a hole in the black blanket. Black hole -- An object whose gravitational pull inside a certain radius is so strong that nothing, not even light can escape it. A black hole forms when the amount of matter in the core of a star undergoing a supernova is great enough to cause a runaway gravitational collapse. i dont know how it was formed though

Answer 5

black hole is a consequence of massive star that collapses over itself, creating a body of huge gravitational attraction, absorbing anything that lies around. Since all the matter starts moving in spiral circles around the black hole, this matter squeezes each other producing a lot of X rays. So that is the way astronomers detect Black Holes, searching for X ray sources in space.

Answer 6

A black hole is a point in space of gravity that is so intense that bends space in such a manner that everything, even light, that approaches too close, falls in.
They can be located by searching for X-rays emitted by matter caught in their gravity, but not yet so close that the Xrays would be trapped.
Try searching the words "singularity" and "event horizon".

Answer 7

People noticed that stars were gone and decided to research the reason.

Answer 8

thats where they dump all the left over black paint, some one spilled white paint it got sucked in to it,

Answer 9

after the collalpse of star, the matter is so dense that anything attracted towards it will never come out

Answer 10

maybe http://en.wikipedia.org/wiki/Black_hole can help you.