Saturday, March 28, 2020

Black Holes Essays (1415 words) - Black Holes, White Hole

Black Holes Black Holes If theories of their existence are true, black holes are the most powerful force in the known physical universe. Many people are familiar with the term black hole, but few people actually know anything about them. A black hole forms as a result of a massive star running out of fuel to burn (Chaisson, 193). Once the star is no longer exerting outward force by burning off gases, it begins to collapse under it's own intense, inward gravity (Chaisson, 193). It is like slowly letting the air out of a balloon. Once the star is compacted to a certain size, while it's mass, or weight, remains the same, it's gravity becomes so powerful that nothing can escape it (Hawking, 87). This critical size to weight ratio is known as the Schwarzchild Radius (Hawking, 87). Once a black hole is created in this way, an invisible area, or line around it exists. If any object crosses this line, it can no longer escape the gravitational force of the black hole (Hawking, 87). This line is called the event hori zon (Hawking, 87). If black holes are proven to exist, beyond theoretical physics, then they would probably be a very common anomaly in this universe. In 1915, Albert Einstein put forth the first real proposition of such an anomaly in his Theory of Relativity (Bunn, Black Holes FAQ). In the 1930s, three physicists, doctors Volkoff, Snyder and Oppenheimer, were able to prove the validity of black holes mathematically. Since then, black holes have become a very important and integral part of science and the over all understanding of the universe. It has been proven, mathematically, that black holes have infinite, gravity based, escape velocities and an immense effect on light, time and even the very fabric of space. All bodies in space have gravity. According to Einstein's Theory of Relativity, this is because bodies with a large mass, or weight, actually warp space (Chaisson, 77). For example, if a two dimensional sheet of cloth, stretched and suspended at four corners, represents space, and a bowling ball is placed in the center, the sheet will warp downward. If a golf ball is then set at the edge of the sheet and allowed to move freely it will be attracted toward the bowling ball, unless the golf ball is traveling at a speed great enough to not be effected by the curve. This critical speed is known as an escape velocity. This is the speed at which an object must travel to escape a body's gravitational force (Chaisson, 77). If a body is compacted, such that it's weight stays the same but it's radius, or size, becomes smaller, it's escape velocity increases in parallel (Chaisson, 196). The simple formula for this, in physics, states that a body's escape velocity is equal to the square root of it's mass, divided by it's radius (Chaisson, 77). For example, if a body's mass is two-hundred, a nd it's size is twelve and one half, the escape velocity would be four. If the size of the same body is reduced to two, while it's mass remained at two-hundred, the escape velocity increases to ten. Since a black hole's size is always decreasing and it's weight is always the same, the escape velocity is infinite (Chaisson, 195). This means that nothing can escape a black hole past the event horizon, not even light. Light is made up of waves and particles. It was discovered, in 1676, by Danish astronomer, Ole Christenson, that light travels at a very high, but finite speed (Hawking, 18). These properties of light govern that it must be subject to forces of nature, such as gravity. Light travels at such a high speed that it is not observably effected by gravity, unless that gravity is very strong. A black hole's gravity is powerful enough to trap light because it's escape velocity, being infinite, exceeds the speed of light (Hawking, 82). This is why a black hole is black. Once light crosses the event horizon it is drawn into the hole in space. Although the light is still hitting objects, it is not able to bounce off to indicate their existence to an observer, therefor the black hole appears

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