black hole, event horizon, collapse, supermassive
What happens when a star dies? Something amazing! Something terrifying! It is something scientists are still trying to explain. Our sun, which is just another star, pulls the Earth in with its gravity. In space, big things pull in small things. Think of placing a big orange bowling ball in the center of a trampoline. This will be the sun. Now, grab a tennis ball (this will be the Earth), and roll it around the edge of the trampoline so it moves in circles. What happens? With each circle, the tennis ball gets closer and closer to the bowling ball, right? That's what happens when the sun pulls in things flying through space. It bends the invisible stuff in space and draws us in. So what happens when the sun that pulls us in breaks down?
The answer is it turns into a vacuum. A great sucking hole in space that eats everything that comes in its path. You may know that light is the fastest thing we know of. Even light cannot escape the pulling power of a black hole. Think of shining a flashlight and watching as the beam of light bends like lemonade being sucked through a straw. A black hole is a thing in space that has so much gravity that everything nearby is drawn into it, even light. How does a big burning star turn into a sucking vacuum?
Stars are like giant heaters. They make new gases, which let out a crazy amount of energy. The small parts within the gas inside of the sun are crashing together to make a new gas and they are letting out a lot of energy. After a very long time, they can run out of gas. When this happens, the star stops growing and the force around it will begin to press in, crushing it like your foot coming down on an empty soda can. When something collapses, it breaks down into something smaller than it was. The dying star gets smaller and smaller, but all of the matter (which is just another word for stuff) inside of it, stays there. This stuff just gets closer and closer together. This is bad news for anything around the star.
This is so strange, yesterday I was the size of a planet.
Let us shrink the Earth to the size of a golf ball. It still weighs the same, which means it will still pull us in, just like our Earth pulls us in now. Go ahead, try to jump away from it. Space cannot handle having something so small, yet so heavy . . . If you think about the size of the sun and the planets that move around it, think about how big something would have to be to keep a whole galaxy in one piece. A supermassive black hole is the largest type of black hole, which has the mass of between a thousand and up to billions of stars. We do not understand these giants yet, but I 'd stay away from them if I were you!
If there is only a hole left, then where did that star go? It's gone! Most of the time, when something dies, we have something left over, like fossils. Not so with stars. When a star disappears, it is an event. A horizon is how far you can see on land or water. This is why the edge of a black hole is called the event horizon; it is the point where all things stop happening, or at least, we cannot see them happen. Once something passes through a black hole, be it a rock, a beam of light, or even a whole sun, it's gone for good. As far as we know, nothing can escape.
Black holes are scary, powerful things. After a star dies, it becomes so heavy, it breaks through everything we know and goes to an unknown place while sucking up anything that is around it. What lies beyond everything we know and can see? To answer that question we would need to go inside a black hole. And I don't think that seems like a very good idea. Do you?
"How Black Holes Work." How Stuff Works.Discovery, 2011. <http://science.howstuffworks.com/dictionary/astronomy-terms/black-hole1.htm>
"Black Holes." Kids' Astronomy, 2008. <http://www.kidsastronomy.com/black_hole.htm>
"Supermassive Black Holes." Science Channel. Discovery, 2012. <http://science.discovery.com/video-topics/space-videos/supermassive-black-holes-the-black-hole.htm>