Black hole is the region in the space where nothing, even the light cannot escape. It appears black because the light hitting its region cannot return back. Despite the fact that we cannot view the interior part of black hole, we can still view its interaction with the other matters around its region. The structure of black hole are all alike although they are of different masses and sizes. A black hole's entire mass is concentrated in an almost infinitely mall and dense point also known as singularity. This singularity is surrounded by the event horizon at which the escape velocity exceeds the velocity of light. A rotating black hole is surrounded by a region called ergo sphere, which in black hole drags the space itself.
Matter is compressed so tightly in a black hole that no other natural force can balance it. In a normal star, eg. the Sun, the inward pull of gravity is balanced by the outward pressure of the nuclear reactions in its core. In the collapsed stars which are also known as white dwarfs or neurons, the other forces stops the collapse. If there is too much mass in a given volume, the body reaches critical density where nothing can prevent it from forming a black hole. Because gravity overcomes the other forces of nature, a singularity follows its own laws of physics. Time and space as we know them are crushed out of existence, and gravity becomes infinitely strong.
As the distance from the singularity increases, the escape velocity decreases. Escape velocity is the speed at which an object must move to get away from the gravitational field of a body. For Earth, the escape velocity is 11.2 km per second. A spacecraft must move at least that fast to escape Earth's gravitational pull and travel to another planet. At a certain distance from the singularity, the escape velocity drops to the speed of light i.e. about 300,000 km per second. This distance is known as the Schwarzschild radius. This radius depends on the mass of the black hole. For a black hole as massive as the Sun, the radius is about 3 km. For every extra solar mass, the radius increases by 3 Kilometers. This radius enfolds the singularity in a zone of blackness - in other words, it makes a black hole black. It gives the black hole a visible surface, which is known as the event horizon.
It is the "point of no return" for anything that approaches the black hole. Once any object enter inside this horizon, it cannot get back out. It is trapped inside the black hole. Anything that enters the black hole increases its mass. As the mass goes up, the size of the event horizon gets bigger and bigger. If the black hole doesn't rotate, then its gravitational influence on its environment is straightforward. If the black hole is spinning, though, then its gravitational effects are more sophisticated. It actually pulls the fabric of space and time along with it - an effect called frame dragging. This area is known as the ergo sphere.
Matter is compressed so tightly in a black hole that no other natural force can balance it. In a normal star, eg. the Sun, the inward pull of gravity is balanced by the outward pressure of the nuclear reactions in its core. In the collapsed stars which are also known as white dwarfs or neurons, the other forces stops the collapse. If there is too much mass in a given volume, the body reaches critical density where nothing can prevent it from forming a black hole. Because gravity overcomes the other forces of nature, a singularity follows its own laws of physics. Time and space as we know them are crushed out of existence, and gravity becomes infinitely strong.
As the distance from the singularity increases, the escape velocity decreases. Escape velocity is the speed at which an object must move to get away from the gravitational field of a body. For Earth, the escape velocity is 11.2 km per second. A spacecraft must move at least that fast to escape Earth's gravitational pull and travel to another planet. At a certain distance from the singularity, the escape velocity drops to the speed of light i.e. about 300,000 km per second. This distance is known as the Schwarzschild radius. This radius depends on the mass of the black hole. For a black hole as massive as the Sun, the radius is about 3 km. For every extra solar mass, the radius increases by 3 Kilometers. This radius enfolds the singularity in a zone of blackness - in other words, it makes a black hole black. It gives the black hole a visible surface, which is known as the event horizon.
It is the "point of no return" for anything that approaches the black hole. Once any object enter inside this horizon, it cannot get back out. It is trapped inside the black hole. Anything that enters the black hole increases its mass. As the mass goes up, the size of the event horizon gets bigger and bigger. If the black hole doesn't rotate, then its gravitational influence on its environment is straightforward. If the black hole is spinning, though, then its gravitational effects are more sophisticated. It actually pulls the fabric of space and time along with it - an effect called frame dragging. This area is known as the ergo sphere.
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