YouTube videoBlack Holes

Black holes have extreme gravity. In fact the gravity is so strong that not even light can escape from the massive gravity that was once a star. Around the edge of a black hole is what is mathematically defined as an event horizon. It is called a black hole because it sucks in all the light around it making it dark. In fact there is even a giant black hole in the center of our galaxy. It may be invisible to the naked eye but you can still use inferred detection to sense them. Some scientist believe that at the center of every galaxy there is a black hole and the black hole at the center of our galaxy has the mass of about equal to 4 million suns and is the size of about a few million earths. The black hole a the center of the galaxy creates the spiral effect of the milky way. Black holes are some of the reason why we can't see most of the stars in the universe. They take in the light from the stars and swallow them up with massive gravity. The problem with black holes besides the fact that hey have powerful gravity that light can't even escape is that they shoot out radiation which can be ver deadly.
Black holes suck the particles in and then crush the particles making heavier and heavier elements. Some black holes have more than one event horizon. With all of this information we currently only know of 14 black holes. Even though some of the stars turn into black holes not all of them do. Most of the stars actualy turn into white dwarfs. Black holes create a gravitational time dilation which cuases time to stop. Some scientists believe that the smallest of blackhles is about the size of an atom. Being that small it still has the mass of a large mountain. Stellar black holes have a mass of about twenty times the mass of the sun. The biggest of black holes are called supermassive black holes that have the mass of about 1 million of our sun squashed together.