Реферат: Black Holes Essay Research Paper Within our

Black Holes Essay, Research Paper

Within our galaxy alone, there are millions upon millions of stars. Within our universe, there are millions upon millions of galaxies. Humans have known the existence of stars since they have had eyes. Although interpretations may have differed on what they were, they were always thought of as white glowing specks in the sky, but the mystery does not lie within what we can see, but what we can not see. There are billions of stars lighting the darkness of our universe, but the question lies in what happens when one of these enormous lamps burns out. Upon many speculations, one of the most fascinating is the black hole theory. Not any star can become a Black Hole. For instance, the possibility of our sun becoming a black hole is highly unlikely, simply because it is too small. Only a very large star has the potential to become a black hole.

The definitions of black boles are somewhat skeptical. Generally, a black hole is an area of super-concentrated mass. So concentrated, that no object can escape its gravitational pull. In other words, once you get caught by it’s gravitational pull, you aren’t getting out again. 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. (11.2 kilometers/second). 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. So if were all living on earth, and earth was a black hole, we would need to go at the speed of light in order to get to the moon.

Even though a black hole’s gravitational pull is enormous, it does have its boundary. This boundary 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 turning back. As stated before, the escape velocity of a black hole exceeds the speed of light, and since going faster than the speed of light is impossible, so is escaping a black hole’s gravitational pull.

Inside the event horizon is where the major speculation begins. Just what happens once you cross the event horizon? Well, once you cross the event horizon, you’ll be spinning around the center at the speed of light. As you get closer to the center, or what scientists call the “singularity”, the theory of the spaghetti effect comes into play. That is, the gravitational pull of the center of the black hole is greater at your feet than your head, thus pulling stronger at your feet, and stretching you out to a point of infinite thinness. This same force is what causes the tides in our ocean, hence the name “tidal forces”. The time in which it takes you to witness this effect depends on the size of the black hole. A smaller black hole means that its singularity is not far away, thus killing you 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. But light won’t be able to bounce of you and back, so no one would be able to see you.

Although living long enough to reach the singularity is just about impossible, if you could reach it; no one knows what would happen. Basically, you would be in a place where time does not exist and all of Einstein’s laws will fail.

Evidence that black holes are real does exist. Even though you cannot see a black hole, as light cannot escape it, 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. Speculation on their deaths is extremely speculative. The theory of black hole evaporation seems to be a popular theory on how black holes die. 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. Stephen Hawkings presented this idea in the 1970?s which was a great contribution to physics.