Black Holes as Unique Cosmic Phenomena - Essay Example

xxxxxx No. 123456 BLACK HOLE ABC of XYZ Department of xxxxxxxxx 22 April, Black Hole Introduction Black hole is one of the most fascinating phenomena in the universe having such a strong gravity that nothing can be escaped from it, even the light as well. Thesis The study of a black hole is helpful to enhance our understanding not only to this unique cosmic phenomenon but also to comprehend the concept of gravity in the real world. Literature Review This section deals with: a. The definition of black hole b. Theoretical aspects c. Types of black holes and how they are formed. d. The concept of an event horizon and gravitational singularities Analysis It critically analyzes the role of gravitational singularities and elaborates what we have understood through literature review and how much our understanding has enhanced about the basics of a black hole. The Conclusion The concluding part brings us on the result that through literature of previous writers and experts as well as by the critical analysis that our learning has been improved with respect to these most amazing objects i.e. black holes. Student Name: xxxxxxxx Subject: Physics Topic: Black Hole  22 April, 2013 Introduction Far away from us in the space, in the center of revolving cosmic storms, the extensive heat, high velocities, and at times the “space revolving buckles”. Photons flew out across of the universe, energized to the limit found in nature and billions of years later, the space stations have detected them above our space. Our ability is to discover the mysteries through our present new age high energy astronomy. The universe is full of amazing astronomical and scientific features, but according to scientists and researchers up till now Black holes are considered as one of the most puzzling phenomena in the universe. The definition of a black hole is enough to get one’s attention as a black hole is a celestial body of extremely intense gravity from which nothing, not even light, can escape (Wald, 1984). The significance of black holes in the cosmos is obvious and same they have the importance to gravitational physics. The theory of presence of the black holes in the universe is our real test that how much we understand the concept of strong gravitational fields. This paper mainly deals with this topic i.e. “the strong gravitational singularity” of black holes. Primarily “a quantitative approach” is applied to involve the use of library sources, journals and “online search” as well. The facts about the topic (black hole) are probable emergent themes based on literature reviews and personal research. This document is developed in three segments. It starts with the brief introduction of black holes and their basic characteristics and particularly the gravitational singularity which is the most distinguished property they possess. This part is based on the previous literature review. The preceding segment deals critical analysis regarding the gravitational singularity of black holes. In the last segment, a conclusion is made based upon literature review and critical analysis. Literature Review A black hole is a hypothetical cosmic body of extremely intense gravity from which nothing, not even light, can escape (Wald, 1984). The borderline of this region where nobody can escape, is called the event horizon, since distant observers outside the black hole cannot see (cannot get light from) events inside. The name “black” given to it is due to the reasons that just like a perfect black body of thermodynamics, it captivates all the light that hits the horizon and in return it doesn’t reflect any amount of light (Davis, 1978). Astronomers have classified black holes into three main categories which are based on their mass, magnetic field, and spin. These include miniature or micro black holes, stellar black holes and supermassive black holes. It happens to be considered that miniature or quantum mechanical black holes have shaped within the Big Bang and there is not any fact to verify its potential presence while in the evolution of the universe (B.J. Carr and S.B. Giddings, 2005). The mass of this sort of black holes are significantly the more compact as compared to that of the Sun and primarily they are made during the Big Bang as a result of intensive outside pressures which squeezed the mass to build the singularity. The stellar black holes are that category which is created by the death of a massive star and generally having a mass of 3 to tens of several solar masses (Celotti, Miller, & Sciama, 2005). Cygnus X-1 is an example of a stellar black hole which has been found in the constellation Cygnus. Cygnus X-I is shown as Appendix-I. Supermassive black holes are the largest among the three. Analysts assume that these particular black holes, which take up the center of a galaxy, maximize their volume for the reason that they attract progressively more stuff through the lustrous heart of the galaxy (Antonucci, 1993). Contrary to external segments of the galaxies, the internal part is congested with stars, which is also a positive factor for the supermassive black holes to get bigger. The volume of these supermassive black holes is worth mentioning as it could be of hundreds of thousands of billions of solar masses (Antonucci, 1993). Till now, few supermassive black holes have been found in space. Black holes found in galaxies M87 and OJ 287 are examples of supermassive black holes and shown as Appendix-II and Appendix-III respectively at the end of the paper. Despite of the fact that the elementary likelihood of black holes prevails in Newtons conventional theory of gravitation and Einsteins theory of gravity which tend to make black holes certain according to various conditions. Before the beginning 1960s, the black holes simply looked like a fascinating theoretical approach without any cosmological plausibleness, however , aided by the finding of quasars in 1963, it turned out to be obvious that pretty spectacular cosmological objects could really exist. In these modern times, it has been considered that black holes exist in the real world and have at least two broad categories i.e. “stellar mass black holes and supermassive black holes”. A black hole is created as soon as any sort of object attains the specific essential density, as well as its gravity results in to fall with a more or less considerably tiny pinpoint. Just the majority of gigantic stars those consisting of much more mass in comparison turn into black holes at the end of their lives. Whenever this type of a star has worn-out, it’s interior thermonuclear energy at the concluding part of its life, results in being volatile and collapses the interior gravitationally at their own (http://burro.astr.cwru.edu/stu/advanced/stars_blackhole.html). The smashing mass of this major object going down through all aspects and compresses the declining star to a point of a zero volume and incalculable density referred to as the singularity. Stellar black holes develop if a huge star cannot anymore deliver energy in its center. Devoid of the radiation from its nuclear reactions to hold the star "puffed up", gravity brings about the core to retract. The stars exterior sheets could possibly boost out towards space, or they may succumb to the black hole to produce it more substantial. The concepts for supermassive black holes continue to be escalating. In accordance with the existing theory they might be produced by gravitational failure of exceptionally enormous gas “chaos” and the generation of supermassive black holes could be associated with the beginning of galaxies. Stars, with a reduced volume of mass, develop into reduced compacted bodies in the shape of either white-colored dwarfs or neutron stars. Einstein’s general theory of relativity, up to a great extent, estimates the facts of the composition of black holes and there are black holes which are categorized according to this theory based upon their spin and a magnetic field. A Schwarzschild black hole is considered as the simplest form of black holes as they are simply based in theory. According to Karl Schwarzschild, these black holes have no spin and magnetic field and an event horizon and point of singularity characterize them. Kerr black holes are most common in space possessing both the spin and magnetic field. Roy P. Kerr described its further characteristics as well .i.e. these black holes consist of ring singularity having two (inner and outer) event horizons and a static limit. A Kerr black is the most common types of black holes found in the space possessing both the spin and magnetic fields. One of the peculiar features of these uncharged black holes is that they have a characteristic rotation about a central axis. Named after scientist Roy Kerr, who proposed its existence, Kerr black holes have special features like ring singularity, two event horizons (one inner and one outer), ergo-sphere and a static limit (http://www.brighthub.com/science/space/articles/72671.aspx). Reissner-Nordstrom black holes also have just theoretical base as they show no rotation. Further they have two event horizons and a singularity point. Albert Einstein introduced his theory of general relativity in 1915. At early on, the great scientist had presented the concept that gravity does impact on movement of light. Just after few months, Karl Schwarzschild proved all the equations and found the solution to Einstein’s equations. These equations illustrated a spherical mass and the gravitational field of a point (Frolov & Zelnikov, 2011). Heusler (1998) describes that as soon as a black hole holds some sort of stable condition after its birth, it can hold only three physical properties i.e. its “mass, charge, and angular momentum” (27). Interestingly, if any two black holes share equal values for these parameters, according to quantum mechanics, they cannot be distinguished exclusively from each other. Einsteins theory of general relativity, his theories regarding gravity, space, and time, all facilitate the existence of singularities. Although, most of the scientists agree on it, even then, when we have to define black hole singularities in some more precise level, then widespread disagreement come into a scene. More accurately a space-time singularity or a gravitational singularity can be described as the location where all quantities become infinite which are used to estimate the gravitational field of the black hole (Delio, 2011). Up till now three types of singularities have been described i.e. path incompleteness, boundary construction, and curvature pathology. A rotating black hole, also called the Kerr black hole, the singularity occurs on a ring. This is called a ring singularity and theoretically becomes a wormhole. The most impressive attributes of a black hole are simple gravitational singularities. Irrespective of any way, a pure black hole space-time comprises of no matter. It is just as a “vacuum” elucidation for the Einstein differential equations, which merely suggests it an answer regarding the field equations when the matter’ solidity and a singularity will be all over zero. A gravitational singularity is taken as a force in pre-relativistic physics which is created by the mass within various matters. Prior to the theory of Stephen Hawking regarding the Hawking radiation, the topic regarding black holes of possessing entropy was averted. However, this principle displays that black holes can expand their energy, which usually retains entropy. Further by the application of the second law of thermodynamics, it also handles incompatible difficulties. Entropy, nevertheless, seems to indicate heat and so temperature. The reduction of energy in a black hole indicates that black holes are also not eternal objects, but somewhat evaporate slowly and gradually. Bigger black holes are generally colder while smaller ones are generally warmer. All identified black holes are usually so large so that their temperatures will be far below than that of the cosmic background rays. Hence they are all getting energy. They will not be going to commence to reduce their energy unless a cosmological redshift greater than one million will be attained. Analysis It is significant to discuss and understand the implications of gravitational singularities because there are certain facts due to which it can be believed that gravitational singularities are really singular. During the 60s, using different definitions especially path-incompleteness definition of singularities, Hawking proved several singularity theorems (Hawking, 1973). Most of these theorems confirmed that in case specific realistic areas were fulfilled, subsequently in particular “scenarios” singularities could hardly be fended off. Noteworthy among these circumstances seemed to be the “positive energy condition” which encapsulates the concept that energy can never be negative. These theorems point out that this universe developed with the that in several situations collapsing material could develop a black hole accompanied by a core singularity. Should all these outcomes guide us to think that singularities are realistic? A large number of researchers, physicists and experts stand against this particular result. Some of them claim that singularities are a way too objectionable for being realistic. Some others assert that the singular actions in the middle of black holes and around the starting of the respective issues to somewhat of a restriction on the domain of applicability of general relativity. Nevertheless, several are inclined to consider general relativity with its concept, together with purely acknowledge its conjecture of singularities being unusual, but properly steady consideration in the geometry of our universe. Till now I have learned that there is hardly any literally acceptable definition of a missing point, therefore, there a fully recognized and an exact explanation of singularity doesn’t exist. Similarly, an essential relationship of singular framework is yet to be established that must be indicated through the existence of incomplete paths and towards the existence of curvature pathology. The question arises what precisely results I should deduce through this specific condition? Certainly, I have two options to come through i.e. on one side the stance of Clarke (1993) and Earman (1995) while Geroch, Canbin and Wald (1982), and Curiel (1998) on the other side. The previous supports the fact that the mettle of philosophy and physics entails that we discover an exact, univocal, and thorough description of a singularity. With this perspective, the supporters of philosophical and physical concerns associated with a prediction of singularity composition based upon general relativity, might be perfectly sorted out. They assert that by using this sort of definition much better questions can be presented and considered to be replied. The other viewpoint is potentially best described to a statement of Geroch, Canbin and Wald (1982): “The purpose of a construction [of ‘singular points’], after all, is merely to clarify the discussion of various physical issues involving singular space-times: general relativity as it stands is fully viable with no precise notion of ‘singular points”. In this particular perspective, the specified physics based on some critical analysis of any sort of specific circumstances must stipulate which definition of singularity is to implement in this particular condition. From the theory of general relativity, I come to learn that clocks operating from various areas inside a gravitational area may not really be concurred together. Regarding a black hole, it particularly manifests itself as well within the subsequent method. Suppose that somebody drops right into a black hole, as well as, whilst sliding, the dropping person flashes some light signals to us. Watching from the secure range away from a black hole, we will discover the occasions between the appearances of flashing light signals to develop into bigger flashes without any limit. To all of us, it might be happened that time had been slowing for that dropping individual because the individual is getting closer to a massive event horizon. As the dropping person comes close to the event horizon, the flashing light signals associated with that individual will appear to us progressively slower. As soon as the individual will cross the event horizon, I will in no way really begin to see the light flashes from the dropping individual. Rather the person will seem to be a “frozen” mark forever on the actual horizon. This is somewhat a deceptive part here as light flashes from the individual might quickly turn out to be seriously red-shifted, as well as quickly end up being virtually detectable. In the viewpoint from the in-falling individual, nevertheless, absolutely nothing uncommon occurs at the event horizon. The person will absolutely not encounter any reducing speed of slowing down of light flashes from clocks neither the individual will observe any significant effect even at the occasion of passing across the event horizon of a black hole. The traveling through the event horizon will be the last movement of that individual in history because after crossing the event horizon, the person will be in a black hole, a massive body from where even no light flash will escape. The idea of an event horizon is really discrete and deceptive as it depends upon the way the occurrences which come about at the event horizon and their connection with the entire framework of space-time. Principally, no substantial happenings are there at the event horizon. In case of a small black hole, the waves of gravitational forces would be extremely strong. This particular fact simply implies that gravitational forces upon the persons feet, nearer to the actual singularity, will be stronger compared to gravitational pulls upon the persons head. Which distinction associated with pressure will be excellent sufficient in order to draw 1 aside. For any adequately big dark “pit” the actual distinction within gravitation from a persons feet as well as mind will be little sufficient with regard to these types of tidal causes to become minimal. A watchful explanation of a black hole based on the general theory of relativity will accordingly depend around the geometrical attributes regarding space-time. We will be required to come across to somewhat more specific that what it implies being “a region where nothing, not even mild, can escape.” Primarily, in case our description is always come up with perception, then there should be some space for outflow. The most typical way of producing this thought accurate provides the idea of “escaping to be able to infinity.” If any particle or mild beams are unable to travel arbitrarily far from your defined bounded area inside the internal of space-time, then that area is certainly one of no escape, and is hence a black hole. The border of this body or region has a very unique property that whenever an entity passes across the event horizon into the particular hole, it by no means last longer than it yet again. With respect to the theory of general relativity, nonetheless, we do work away with gravitational singularities, and alternatively postulate a spherical space-time geometry that creates the consequences which we associate with gravity. Therefore a black hole isnt just a simple “thing” inside space-time; it is on the other hand “an attribute of space-time alone” (Hawking, 2012). Another interesting situation has been highlighted by Stephen hawking that by the integration of the theory of general relativity and quantum mechanics, time and space produce a four dimensional space which do not possess any boundaries or singularities (Hawking, 1988). With a mass projection, Hawking’s this theory seems logical enough to explain lots of observed characteristics of the universe and space e.g. large scale uniformity, stars, galaxies, the start and end of time, and even the life of human being. I would like to avail this opportunity to share my deep appreciation as well as serious regards to Professor XYZ with respect to his particular exemplary guidance, keeping track , as well as prolonged inspiration all the way through the study associated with this paper. His true blessing, assistance as well as all pieces of advice will always remain with me as cherish-able memories. I also express my feelings of thanks to the whole staff of the Buehler Observatory for their cooperation and professional assistance for providing important information during the period of my assignments throughout this course. The Conclusion The particular natural analysis with respect to space-time singularities and also black holes provide quite a few philosophical complications. To get started, we discussed the description of black holes, its basic characteristics and then we deal with the thought of description and value of singularities. Questions come into sense that should they come to be outlined with regards to incomplete paths, missing points, or curvature pathology? Should many of us possibly presume that there is one perfect reply to this query? Is it required that we may incorporate our ontology, or do they will as an alternative simply reveal the break-down of your certain physical principle? It has apparent associations for the concern of how we have to study and understand the ontology regarding valuable information. The controversy on the facts loss paradox furthermore demonstrates the conceptual significance about the partnership among diversified and powerful ideas. At the origin, the discussion gets finished whereby our valuable theories breakdown. When can certainly they will be creditworthy, and where they are required to be succeeded by more suitable hypotheses? Black holes look like significant for our comprehension to the association among matter and space-time. As described above, when matter shapes into a black hole, it happens to be evolved in to a rigorously gravitational body. Whenever a black hole dissolves, space-time curvature will be metamorphosed into normal matter. Consequently black holes present a significant area pertaining to figure out the ontology regarding space-time and normal celestial bodies. Singularities and also black holes are probably our most preferred sources regarding the specifics of quantum gravity that might be the best prospect to get certainly standard physical information of the globe. As a result, they provide glimpses directly into the greatest dynamics regarding matter, dynamical laws, space and also the time. These glimpses might seem to require a conceptual revision because they simply require the quantum mechanics or perhaps only the theory of relativity theory. According to Stephen Hawking, it is actually the gravity which is responsible for making mass structures and bringing changes in the universe. The gravitational laws apply to the formation of black holes in space but interesting point is that gravity is an eternal attractive force which persists throughout the universe and due to this property, Hawking argues that universe is either contracting or expanding. The theory of general relativity provided a base to the Hawking’s big bang theory that a state of infinite density was present in the past and probably it was a projection of the start of time in universe. It means that if the whole universe is collapsed again, another state of indefinite density would come about which would result in the end of time as well. But even at this point when the whole universe would be collapsed, there would be singularities related to some specific regions. These singularities would be collapsed to form black holes in the space. Here the Hawking theory brings us to the conclusions that if someone falls into a black hole; these singularities would result in the end of time (Hawking, 1988). During the events of big bang and singularities, all the scientific theories and laws would fail and therefore God would have ultimate options to rejuvenate the whole universe once again. Black holes have been also observed to offer a significant evaluating place to analyze the conceptual issues hidden in the theory of general relativity and quantum theory. The issue regarding the black hole development is unitary i.e. whether the black hole advancement increases the size of the matter or not. Likewise, the debate on the information loss paradox is seen as an argument in excess of whether space-time or a subjective dynamical express space needs to be perceived as getting much more elementary. Will probably space-time alone be an emergent creature that belongs simply to a valuable physical theory? There is considerable disagreement within the significance of singularities. Many eminent researchers, physicists, and experts think that the general theory of relativity signals a significant deficiency in the concept. Singularities are a sign that the description provided by the theory of general relativity is wearing down. Others believe that singularities represent a thrilling new horizon to strive for and explore the universe. They provide us a hypothetical ground so that we may experience, observe, quantify and realize them to profound our comprehension towards the physical world. Appendix-I Cygnus X-I (Source: http://gems.gsfc.nasa.gov/images/targets/Cyg-X-1.jpg) Appendix-II M87 Black Hole Mass (Source: http://www.lastwordonnothing.com/wp-content/uploads/2010/08/m87_cfht.jpg) Appendix-III OJ287 (Source: http://blackholes.stardate.org/images/resources/news/dn13166-1_400.jpg) Works Cited Antonucci, R. Unified Models for Active Galactic Nuclei and Quasars. Annual Reviews in Astronomy and Astrophysics 31 (1): 473–521. 1993. Print. Carr, B.J & Giddings S.B. Quantum black holes. Scientific American, 2005. Print. Celotti, A., Miller, J.C., & Sciama, D.W. Astrophysical evidence for the existence of black holes. Classical and Quantum Gravity 16 (12A): A3–A21. 1999. Print. Clarke, C. The Analysis of Space-Time Singularities, Cambridge: Cambridge University Press, 1993. Print. Curiel, E. The Analysis of Singular Space-times, Philosophy of Science, 66, 1998. Print. Davies, P. C. W. Thermodynamics of Black Holes. Reports on Progress in Physics 41 (8): 1313–1355, 1978. Print. Delio, Ilia. The Emergent Christ: Exploring the Meaning of Catholic in an Evolutionary Universe, Maryknoll NY: Orbis Books. pp. 183, 2011. Print. Earman, J. B., Crunches, W., and Shrieks. Singularities and Acausalities in Relativistic Spacetimes, New York: Oxford University Press, 1995. Print. Frolov, V.P., & Zelnikov, A. Introduction to Black Hole Physics. Oxford: Oxford University Press, 2011. Print. Geroch, R. and L. Can-bin and R. Wald, 1982, “Singular Boundaries of Space-times” Journal of Mathematical Physics, 23: 432-435 Hawking, Stephen. The beginning of Time. Cambridge University, 2012 Hawking, Stephen. A brief history of time. Random House Publishing Group, 1988 Hawking, S.W. The Large Scale Structure of Space-Time, Cambridge University Press, 1973 Heusler, M. Stationary Black Holes: Uniqueness and Beyond. Living Reviews in Relativity 1 (6), 1998. Print. http://blackholes.stardate.org/images/resources/news/dn13166-1_400.jpg http://www.brighthub.com/science/space/articles/72671.aspx Wald, Robert M. General Relativity. University of Chicago Press, 1984. Print. Read More