What is a black hole?

Answer 1

Black holes are objects so dense that not even light can escape their gravity, and since nothing can travel faster than light, nothing can escape from inside a black hole. On the other hand, a black hole exerts the same force on something far away from it as any other object of the same mass would. For example, if our Sun was magically crushed until it was about 1 mile in size, it would become a black hole, but the Earth would remain in its same orbit.

Answer 2

A black hole is an object with a gravitational field so powerful that even electromagnetic radiation (such as light) cannot escape its pull.

Black holes can be divided into several size categories:

Supermassive black holes containing millions to billions of solar masses are believed to exist in the center of most galaxies, including our own Milky Way.
Note: 1 solar mass = the mass of our sun.
Intermediate-mass black holes, whose size is measured in thousands of solar masses. Intermediate-mass black holes have been proposed as a possible power source for ultra-luminous X ray sources.
Stellar-mass black holes have masses ranging from 1.44 to 15 solar masses. This is narrower than the range of masses found in "normal" stars because of the way in which black holes are formed: the smallest star which is large enough to produce a black hole will form a black hole of 1.44 solar masses (the Chandrasekhar limit); large stars usually blow away a significant percentage of their mass in supernovae as part of the process that forms black holes.
Small black holes which are smaller than stellar-mass black holes but larger than micro black holes.
Micro black holes, which have masses similar to that of a helium atom.

Answer 3

A black hole is aregion of space possessingt a gravitational field so intense that no matter or radiation or even a light can escape from it.
it has a very high density & objects could fall but no object could come out of it .
the value of acceleration due to gravity is so high that even photons can not escape from it surface

Answer 4

In a nutshell, a black hole is an object who's gravitational pull was so great, that the molecules broke in on themselves, and are put back to their essential atoms.

It gets it's name because not even light passing by can escape its vast gravitational pull.

Answer 5

I presume that you know what is space time, now if earth is rotating along it's imaginary axis, so it is in the surface of space time just curving it with it's mass. just consider a catastrophe occurred and the earth started shrinking and it's mass becomes denser and denser so finally it becomes a large mass inside a small volume,obviously the density becomes very high because

Density = Mass/Volume
Mass is directly propotional to mass as mass increases density increases so whay happens is a SINGULARITY is formed in the surface of space time ie. a deep depression
in the fabric of space time so what happens is a high gravitational field is formed this is explained by Newtonian mechanics that gravitational force between two masses is directly proportional to the masses of the individual objects

Fg = G m1 m2 / r^2

so any object coming near to this singularity or depression it gets attrcted to the mass we first saw according to the above equation so this SINGULARITY OR DEPRESSION IN SPACE IS CALLED A BLACK HOLE

Read the breif history of time by stephen hawkings for more information

Answer 6

A Black hole is like a very large thin oval and any thing near it including air,planet ,rocks, stars and solar-system will be sucked in with its vast gravitational pull.

Answer 7

It is result of a neutron stars which contains very much gravitational pull that even light doesn't escape from it.

it is named so becoz it is looks like a hole which is black in color

Answer 8

a star has hydrogen molecules in its hemisphere. these molecules combine to form helium. this is nuclear fusion. at a point of time the entire hydrogen molecules in the outer layers are exhausted and helium molecules are formed. then the hydrogen atoms in the core start combining to produce helium. and after million years even these get exhausted. then the star expands because it has lots of energy in store and its called "RED-GIANT" after it liberates energy, its temperature will reduce because of loss of energy then the star shrinks called "WHITE-DWARF" and even after that it keeps losing energy continuously.
when energy is low it suddenly contracts to less than 1/4 th of its size and because of this gravity will be more. and the gravity will be so high that even light cannot escape from its effect. this is the BLACK HOLE. in simple words it is a dead star which attracts every possible thing around it with its high gravitational field around it...

Answer 9

A black hole is when a star about 3 times as big as our sun becomes a supernova then after that th supernova either becomes a pulsar or a black hole.

Answer 10

after a star is dead whole of its light energy and lusture is lost. it becomes a mass with high gravitational n magnetic field n also lots of attraction. so it attracts every body which comes to its vicinity. So every body that is trapped inside it does not sees anything outside it and there is complete black. hence the name black hole........