What Are Black Holes?

Black hole is a collapsed star that light can not escape gravity.

Black holes are one of the most hot topics amongst scientist these days. It is true that we have very less knowledge about these mysterious objects or rather absence of objects. Why i said absence of object, because their volume is 0. Yes you read that correctly, ZERO!. Our human minds cannot grasp anything that has zero volume. Do you know the formula of density i.e. Mass over volume.  The answer of any number divided zero comes to infinity. That means black holes have infinite density. Can you imagine a thing that has 0 volume and infinite density? It melts my brain.  

Black holes are many more times higher than our sun. They are formed when stars die with big supernova. Those stars that are many more times larger than our sun turns into black holes after supernova. Scientist believe that black holes are gates to the outer world. As we know that volume outside our universe is 0. And ya, one more thing, their gravitational field is so great that they suck everything around them. Yes they are very hungry! Lol.  So better not to wander around them.

Astronomers believe that centre of every galaxy has one big blackhole, that makes matter of galaxies rotate around its centre. When anything goes into the blackholes, their concept of time diminshes, the body turns into inexistence, and nothing can escape its gravity. Not even the light. That's why they are black. Because we cant see anything inside it, cannot hear anything inside it.
These are unknown animals of an unknown jungle. :)

Black holes are some of the strangest things in space. A black hole sucks in anything that gets near it. Nothing can escape from a black hole—not even light. No one has really seen a black hole. You cannot see black holes because they do not give off any kind of light. Physicists used math to predict that black holes exist. Nothing escapes from a black hole because its gravity is so strong. Gravity is a force that pulls one thing to another. Gravity is the force that holds you down on Earth. When you jump up, Earth's gravity pulls you right back down. Earth's gravity also makes the Moon orbit (go around) Earth. The more matter (stuff) that is packed in a star, planet, moon, or other object, the stronger is its gravity. Gravity makes an object with more matter pull an object with less matter toward it. The Sun has a lot more matter than Earth. The Sun's gravity pulls on Earth.