C reative
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Higgs
CPH Theory is based on Generalized light velocity from energy into mass.
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No Exit - A Paper About Black Holes
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No Exit - A Paper About Black Holes
Black holes are one of the universe’s great mysteries. We know they’re out there, yet no astronomer has ever seen one. What are black holes? What are the common misconceptions surrounding them? What is some of the latest research on them? These are a few of the questions we will be exploring in this paper. To begin with, what is a black hole? According to astronomers, a black hole is defined as a “region in space where the gravity is so high that the fabric of space and time has curved back in on itself, taking the exit doors with it” (Tyson, 282). Another description of them comes from the Encarta Dictionary, “areas in space with such a strong gravitational pull that no matter or energy can escape from it.” Black holes are formed when a star dies. A star is a massive fusion reactor, its size determined by the balance between the gravitational forces and the explosive forces. When that delicate balance gets disrupted and the star starts to die, the nuclear fusion reactions stop and the gravitational forces pull material inward, which compresses the core. This causes the core to heat up, triggering a supernova explosion. The explosion propels the material and radiation far out into space. The only thing that remains is the highly compressed and massive core. The gravitational forces are so strong that not even light can escape and the black hole literally disappears from sight. The force of the gravity is also enough to cause the black hole to slip through the fabric of space-time, creating a hole in space-time. This is why they’re given the name of “Black Holes” (Freudenrich, 2). The core becomes the central part of the black hole called the ’singularity.’ The edge of the beginning of the black hole is called the event horizon. It is the point of no return, the boundary between the isolated volumes of space-time and the rest of the universe. Once across the event horizon, there is no coming back. What happens inside of a black hole is unknown to us, because our current theories about physics don’t apply to a singularity such as the one at the core of a black hole. An accretion disk is formed from the gas and dust and other matter that is drawn towards the black hole. It lies before the event horizon; the matter making up the accretion disk heats up as it is drawn to the event horizon and will radiate x-rays which reveal to us the black hole’s location and mass (Smithsonian). By convention, the size of the event horizon is seen as the size of the black hole. This is a clean quantity in which to calculate and measure (Tyson, 284). The radius is called the Schwarzschild radius after Karl Schwarzschild, whose work led to the initial theories about black holes. There are two types of black holes, Schwarzschild black holes and Kerr black holes. The difference between the two of them lies in their cores. Schwarzschild black holes have cores that do not rotate and consist only of an event horizon and singularity (and sometimes an accretion disk). Kerr black holes, named for Roy P. Kerr are black holes whose cores rotate because the stars they formed from rotated and the law of conservation of angular momentum carries over the rotation from the dying star to the final stage as a black hole (Freudenrich, 3). Because of the difference in the core, a Kerr black hole has more parts to it than a Schwarzschild black hole. In addition to the event horizon and the singularity, a Kerr black hole consists of an ergosphere and a static limit. The ergosphere is defined as “An egg-shaped region of distorted space around the event horizon” (Freudenrich, 3). The distortion is caused by the rotation. The static limit is the boundary between the ergosphere and normal space. The difference between the ergosphere and the event horizon is that something can still escape from the ergosphere, provided that it could gain enough energy from the rotation to propel itself clear. What would happen to someone or something that wandered too close to a black hole? Say for example that you are falling feet first towards the black hole. As you get closer to it, its force of gravity grows astronomically. You would not feel this at all, because you are weightless. What you do feel is far more ominous. The black hole’s gravity force is accelerating your feet faster than your head, because your feet are closer than your head to the center of the black hole. The difference between the gravity at your feet and the gravity at your head is called the tidal force. The tidal force grows sharply as you get nearer to the center. Your body would stay whole until the moment that the tidal force grew larger than your body’s molecular bonds. Your body then breaks apart into segments that also break apart and divide until you are nothing but a stream of unrecognizable particles. But that’s not the end of it, because the tidal forces are all moving you towards the exact same spot (the black hole’s center), you are not only getting ripped apart, but you are also getting squeezed through the fabric of space-time like toothpaste from a tube (Tyson, 285). There are several common misconceptions about black holes. To use one example, black holes are not universal vacuum cleaners that will eventually suck up the entire universe. A black hole is, put simply, a gravitational field and at a reasonable distance away, its pull is no more than a normal object of similar mass. The black hole’s gravity only gets extreme when you come close to it. Another common misconception about black holes is that black holes are not funnels. They are often graphed as curvatures on a flat sheet, giving the appearance of a funnel (this is to show the strength of the gravity surrounding it), but black holes themselves are not funnels (Horizons, 239). It is also a misconception that since light cannot escape from a black hole, it is impossible to get any energy out of it. Matter flowing into the gravitational field accelerates inward and to help preserve angular momentum, it flows onto the accretion disk. The accretion disk is so hot that it can emit x-ray and gamma ray bursts and as it spins, it also can spit out some very powerful beams of gas and radiation from the disk’s axis of rotation (Horizons, 243). This history of black holes began two centuries ago with an English geologist, John Mitchell. Mitchell theorized that gravity could become so strong that not even light (which travels at 299,792,458 meters per second in a vacuum) would be able to escape. He also theorized that if such a thing were possible, the object would have to be incredibly dense as well as massive. He called such objects, “dark stars.” His ideas were published briefly, but then discarded out of hand (University of Illinois). Simon Pierre LePlace predicted the existence of black holes in his work, Le Systčme du Monde, “… [It] is therefore possible that the largest luminous bodies in the universe may, through this cause, be invisible” (Amazing Space). Then came Albert Einstein. In 1916, he published a mathematical theory about space and time that became known as the general theory of relativity. He treated space and time as if they were one entity. His equations showed that gravity could be described as a sort of curvature of space-time. On the heels of this groundbreaking theory comes Karl Schwarzschild, who using Einstein’s theory, almost immediately found a solution to the equations that described the gravitational field around this nonmoving, electrically neutral lump of some matter. This was the first actual scientific description of a black hole. His solution showed that if matter was packed together tightly enough, into a small enough volume, then space-time would curve back into itself. Objects could still follow various paths into the black hole but nothing could escape, not even light, thus leaving the inside of the black hole completely beyond the observation of an outside viewer (Horizons, 238). After Schwarzschild, came Subrahmanyan Chandrasekhar, a pioneer in the study of white dwarf stars. This lead to a further understanding of the limits of mass, which would determine whether a star dies a white dwarf, a neutron star, or a black hole. Roy P. Kerr uncovered the solution to charged black holes with rotating cores in 1963. In 1964, John Wheeler coined the term, “black hole.” That same year, neutron stars were discovered by Jocelyn Bell-Burnell. In 1970, Stephen Hawking defined the modern theory of black holes and Cygnus X-1 was found. Cygnus X-1 was the first decent black hole candidate located by astronomers. It emitted x-rays and has a companion that has a mass greater than a neutron star, but is actually smaller than Earth is (Amazing Space). Astronomers at the Keck Observatory in Hawaii are currently studying the black hole in the center of the Milky Way; in hopes that the data they gather from their experiments will give them a greater insight into what is still one of the universe’s biggest mysteries. One of the huge Keck telescopes has been equipped with an incredible new tool that increases its power. A laser guide has been added to the telescope, making it possible for the telescope to capture pictures clear as any taken from actual satellites in space. The astronomers at the Keck Observatory have aimed the laser guide directly at the black hole located near the Sagittarius constellation at the center of the galaxy (Smithsonian). The laser fires into what appears to be the heart of the black hole (actually ending some 55 miles above the surface of the Earth), the signal there allowing the telescope to compensate for the blur of Earth’s atmosphere. The telescope will stay locked on to the same part of the sky for a period of four hours while a camera takes one 15 minute exposure after another. The astronomers and graduate students working there are hoping that some of the new data they are collecting will put them one step closer to finding out how stars close to these black holes are born and how the black holes distort the fabric of space itself. (Smithsonian) The team at Keck is using the laser as an artificial guide light, allowing them to explore more of the sky than they’ve previously been able to. Erasing the distortions that come with air currents and the Earth’s atmosphere is possible with technology called adaptive optics. Adaptive optics sharpens up the pictures and gets rid of the distortions, but it has one serious drawback. The technology requires a strong and clear guiding light to use as a reference point. So it would only truly work if pointed at something close to a bright star or planet, effectively limiting the scope of the astronomers’ work. That barrier has been removed thanks to the laser’s artificial guide light (Smithsonian). Andrea Ghez of UCLA, one of the astronomers at the Keck Observatory and leader of this particular team, describes the black hole and the area around it as “the thriving city center of the galaxy, compared to the suburbs where we are. Stars are moving at tremendous speeds. You’d see things change on a time scale of tens of minutes” (Smithsonian). She and another UCLA astronomer, Mark Morris, hope to gather the first evidence that the stars do indeed travel along the weird orbital paths predicted by Einstein’s theory of relativity. If this is so, then the stars would trace out something like a Spirograph pattern over time, gradually altering the points of their closest approaches to the black hole. Andrea Ghez and her colleagues are about eight years away from spotting that shift, according to an article about black holes in the Smithsonian magazine. As the research progresses, some of the newest findings are quite startling to the teams of astronomers observing them. One of them is the discovery of scores of massive young stars in the same neighborhood as the black hole. Only five to ten million years old and roughly ten times more massive than our sun, no one can quite explain what they are doing there. Normally, new stars are birthed in clouds of gas and dust, in a calm environment. This place, the black hole’s neighborhood is anything but. There’s no real reason to explain why these stars are there. The astronomers are baffled by this finding (Smithsonian). It is theorized that these young stars will self-destruct in a few million years, leaving behind small black holes of their own. These small black holes (only about 20 miles wide) would then swarm around the central super massive black hole. Mark Morris stipulates that “You’ll have black holes swing past each other in the night, and stars moving through this demolition derby. A near miss between one of these black holes and a star could scatter the star into the supermassive black hole or out of the galactic center entirely” (Smithsonian). The new findings about black holes are helping astrophysicists and theorists to develop new models for how the universe was created and how it has evolved since then. Avi Loeb, director of the Institute for Theory and Computation at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, believes that all galaxies started with “seed” black holes (as of yet unexplained) and that these black holes were tens to thousands of times more massive than our sun. These seed black holes collided more often and grew exponentially. As they grew, they formed raging quasars which blasted gas out of the galaxy entirely. After the gas was depleted, the supermassive black holes sat “dormant and starved,” says Loeb (Smithsonian). Our Milky Way galaxy has never fueled a quasar and only absorbed some few, small galaxies. But on the horizon, there lies a terrifying collision. The Andromeda galaxy is squarely set on a collision path with the Milky Way. Loeb and a colleague, T.J. Cox, believe the two will start to merge in about two billion years from now, forming what they call, “Milkomeda.” The two galaxies’ supermassive black hole will collide and ignite a new quasar (Smithsonian). Andrea Ghez says that “it’s hard to believe that black holes really exist, because it’s such an exotic state of the universe.” She’s content with the data pulled from the three days of her planned observations. They’ve got more than enough to keep busy and they’ve identified a few more big young stars to add to their analysis (Smithsonian). Black holes are as deadly as they are fascinating and there is still much that we don’t know about them. Recent research, as evidenced by the efforts of Ghez and Loeb, have shown us that black holes can be used to explain parts of how the universe works, but largely they remain a mystery. Bibliography: Freudenrich, Ph.D., Craig. “How Black Holes Work.” 26 November 2006. HowStuffWorks.com. <http://science.howstuffworks.com/black-hole.htm> 04 April 2008. Board of Trustees. “A Brief History of Black Holes”. University of Illinois. 04/04/2008 <http://archive.ncsa.uiuc.edu/Cyberia/NumRel/BlackHoleHistory.html>. Amazing Space. “Pathway to Discovery”. Space Telescope Science Institute. 04/04/2008 <http://archive.ncsa.uiuc.edu/Cyberia/NumRel/BlackHoleHistory.html>. Irion, Robert. “Homing In On Black Holes”. Smithsonian April 2008: 45-53. Seeds, Michael A. Horizons: Exploring the Universe. Belmont, CA: Thomson-Brooks/Cole, 2008. Tyson, Neil DeGrasse. Death by Black Hole. New York: W.W. Norton & Company Inc., 2007.
Source: http://bkesler.wordpress.com/2009/01/15/no-exit-a-paper-about-black-holes/
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