Реферат: Black Holes Essay Research Paper In our - Refy.ru - Сайт рефератов, докладов, сочинений, дипломных и курсовых работ

Black Holes Essay Research Paper In our

Темы по английскому языку » Black Holes Essay Research Paper In our

Black Holes Essay, Research Paper

In our galaxy, there are millions of stars. In our universe, there are millions of galaxies. Humans have known about stars since the beginning of our existence. What we think of these mysterious things have changed over time. Even in periods as short as a lifetime our ideas have changed. I remember when I was young I thought of stars similar to the way astronomers thought many years ago, that the Earth was the center of the universe. As I got older I began to think more like the astronomers of today, That the earth is just a small part of a huge galaxy in a huge universe.

There are billions of stars lighting the darkness of our universe, when those stars burn out what happens? One of the theories is the black hole theory. Not any star can become a Black Hole. The possibility of our sun becoming a black hole is very unlikely, it is too small. Only a very large star has a chance to become a black hole. The definition of a black hole is, an area of super-concentrated mass. So concentrated, that no object can escape its gravitational pull. In other words, once something gets sucked in by it’s gravitational pull, it isn t getting out. The velocity you need to break away from a gravitational pull is called the “escape velocity”. Roughly, earth’s escape velocity is about 25,000 M.P.H. If that sounds like a lot the Earth’s mass is nothing compared to the mass of a star that has the potential to become a black hole. A black hole has so much mass in such a small area, that its escape velocity is greater than the speed of light.

Even though a black hole’s gravitational pull is enormous, it does have its limit. This limit is called the “event horizon”. This event horizon is the point where the black hole’s gravitational pull begins. Once you cross the event horizon, there is no way out. Inside the event horizon is where the major speculation begins. Just what happens once something crosses the event horizon? Once something crosses the event horizon, it will be spinning around the center at the speed of light. As it gets closer to the center, or what scientists call the “singularity”, the theory of the spaghetti effect starts. The spaghette effect is when the gravitational pull of the center of the black hole is greater at your feet than your head, which results in pulling stronger at your feet, and stretching you out to a point of infinite thinness.

The time it would take to see this effect depends on the size of the black hole. A smaller black hole means that its singularity is not as far away, which means whatever gets caught in the black hole will be destroyed quicker. If you could somehow get into a horizon safely and look around, images around you would be distorted. And since light can go into a black hole, you can see outside images fine. Although living long enough to reach the singularity is just about impossible, if you could reach it; no one knows what would happen. Evidence that black holes are real does exist. Even though you cannot see a black hole, you can measure how much mass there is in an area. And if you have a large quantity of mass in a small area, there is a good chance it is a black hole.

Black holes do not live forever, and as stars, they die. Theories of what happens when black holes die are just speculations. The theory of black hole evaporation is the most popular one. Black holes emit radiation, and the energy to emit this radiation comes from the black hole’s mass, thus shrinking the black hole. Gradually, a black hole wears itself out into nothing.

Black holes are still very mysterious things. Nobody can go into a black hole or even get near it to do studies, and it is unlikely anyone will anytime soon. Right now everything we know about black holes could be wrong. Maybe one day we will be able to send satellites into black holes, but for now we will only be able to make more theories about these powerful mysteries.