Hi im Axeem A black hole is a super dense object that has an intense gravitational pull. There are two parts to a black hole, a singularity and a event horizon. If you were to take a slice of a black hole right through its center it would look like this:
The event horizon is where the force of gravity becomes so strong that even light is pulled into the black hole. Although the event horizon is part of a black hole, it is not a tangible object. If you were to fall into a black hole, it would be impossible for you to know when you hit the event horizon. For a mathematical derivation of the radius of a event horizon see below.
The singularity is not really a tangible object either. According to the General Theory of Relativity the Singularity is a point of infinite space time curvature. This means that the force of gravity has become infinitely strong at the center of a black hole. Everything that falls into a black hole by passing the event horizon, including light, will eventually reach the singularity of a black hole. Before something reaches the singularity it is torn apart by intense gravitational forces. Even the atoms themselves are torn apart by the gravitational forces.
Formation of a Black Hole:
Imagine a star which is much more massive than our sun, and which has a mass, called the critical mass, which is large enough to cause a black hole to form. What keeps this star from collapsing onto itself and becoming a black hole? The answer is that there is an intense pressure caused by nuclear reactions within the sun. When the fuel that feeds the nuclear reactions gets used up the massive star cannot support itself anymore. It then collapses to form a black hole.
It is interesting to note that when a black hole is formed by a collapsing star it is actually impossible to watch the final steps of the formation of the black hole from a stationary external reference frame. An external reference frame is a place where one watches...