what is a black hole?

Answer 1

an object in space having that much gravity that nothing which came too near can escape anymore, not even light

Answer 2

A region of space so densely packed that nothing, not even light,
can escape from it is known as a black hole.
OR
"A tear in the fabric of spacetime is a balck hole."

According to Einstein's theory, if enough matter is packed into a small enough volume, the well will get so deep that the matter inside can never escape. A circle of no return forms. Any matter that passes the point of no return can no longer escape to the outside world. It necessarily keeps collapsing, moving towards the center. The well gets deeper and deeper until finally a hole is literally torn in the fabric of spacetime: the density of matter at the center becomes essentially inifinite, at least to the extent that Einstein's theory of gravity is still valid. Thus, what I mean by " a hole in the fabric of spacetime" is: a tiny region of space where the known laws of physics break down. A black hole is then a region of space so tightly packed with matter, that nothing, not even light can escape. Hidden at its (crunchy?) center is a tear in the fabric of spacetime. Anything that falls into this region of space is irrevocably lost to the rest of the universe. No light can emerge or pass through this region, so it appears totally black. In some sense therefore, a black hole marks a boundary to spacetime: a horizon beyond which no one can see without travelling through it. This radius of no return is called the event horizon of the black hole.

Answer 3

A black hole is an object predicted by general relativity with a gravitational field so strong that nothing can escape it — not even light.

A black hole is defined to be a region of space-time where escape to the outside universe is impossible. The boundary of this region is a surface called the event horizon. This surface is not a physically tangible one, but merely a figurative concept of an imaginary boundary. Nothing can move from inside the event horizon to the outside, even briefly.

Theoretically, a black hole can be any size. Astrophysicists expect to find black holes with masses ranging between roughly the mass of the Sun ("stellar-mass" black holes) to many millions of times the mass of the Sun (super massive black holes).

The 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. It has also been hypothesized that black holes radiate energy due to quantum mechanical effects known as Hawking radiation.

Answer 4

The term black hole was coined in 1969 by an American scientist John Wheeler. It is defined to be a region of space-time where escape to outside universe is impossible. They are charecterized by their extremely strong gravity, which is so strong that not even light can escape, as a result black holes are invisible. However, they can be detected if they have a close companion star. Their gravity pulls gas from the outer star, forming an accretion disc thatspiralsround the black hole high speed, heating up & emitting radiation. Eventually, the matter spirals in to cross the event horizon (the boundary of black hole), thereby disappearing from the visible universe.

Answer 5

A black hole is a small but extreamly dense object that has so much mass in such a small space that its gravitational pull starts to fold into itself it then starts to pull in anything within its gravitational pull the closer the object to the black hole the stronger its pull on it will be. And actualy stuff can excape a black hole in the form of radiation. As far as I know the gravitational pull from a black hole is less on its top/bottom and that is the most likely place radiation will excape from it. Lots of fun and interesting things happen inside a black hole so much we currently dont understand them as well as we would like currently :)

Answer 6

Forms after the explosion of a huge star. It's extremely dense and its force of attraction is so high that even light cannot escape it which is why it's called a 'black' hole.

Answer 7

Hiiii,

See when a planet exists or a star. It has its own gravitational force. When it explodes, noting is left but only the gravity field remains unchanged. So, it is called black hole.

the gravity makes some bodies to revolve around it.

byeeee

Answer 8

sometimes,when a big star dies,it collapses and creates a black hole.black holes are LIKE GIANT VACCUM CLEANERS IN SPACE.they are so dense and heavy that their gravity sucks in everything around them.black holes even suck in light instead of reflecting it,which makes them invisible.....

Answer 9

Hello Friend!
When the stars are in their last stage( during their death ), they suddenly explode forming neutron stars and black holes.

Answer 10

A hole which is black in color ? ( er.. like a man hole of course)