The Concept of Black Holes - Essay Example

Running Head: Black Holes Black Holes [Institute’s Table of Contents Table of Contents 2 Concept of Black Holes 3 Types of Black Holes 4 Hawking Radiation and its Effects 5 Detection of Black Holes 6 Vicinity of a Black Hole 6 Conclusion 8 References 9 Concept of Black Holes For centuries, humans have shown their interest in skies, which resulted in development of telescopes that allowed scientists to view objects and energies that are not visible to human eyes. Black holes are one of such discoveries of human astronomy that are considered as space objects that earlier used to be stars but transformed into condensed thick objects due to their own gravity. In 2004, Susskind & Lindesay (pg. 87) quoted, “A black hole is a section of space-time from which nothing, not even light, can escape, and general relativity calculates that an adequately dense mass will distort space-time to shape a black hole.” Based on this concept of black hole, scientists have tried to describe unseen surface of the black hole as ‘event sphere’ that at a conflict, does not allow any particle or object to return and thus scientists explain event sphere as the point of no return. The scientists named black hole as black because of its properties that mainly include absorbing everything that comes into its reach resulting in everything disappearing, thus black. Quantum physics and mechanics have contributed significantly in understanding of black holes that indicate that although black holes absorb everything that comes in its reach, however, there have been observations of a very weak emission from the black holes that has a temperature, which is inversely proportional to the mass of the black hole (Taylor & Wheeler, 2000). Scientists believe that every galaxy has these black holes at their cores, which absorb all the left-out energies of these galaxies and thus they are denser and heavier than even the sun, which is a theoretical assumption and thus, has been criticised by many experts in the field who even do not believe in the existence of black holes. However, scientists who believe in black holes indicate that with their characteristic of absorbing everything, the black hole creates a spinning disk that confine nearby particles in the space. Few scientists have been successful in observing this accumulation-spinning disk on radio, x-ray, and gamma ray bands since emissions of black holes often become very warm and thus, come on the x-ray bands (Susskind & Lindesay, 2004). With these observations, a huge number of scientists have now proofs of real black hole at the core of Milky Way galaxy that is heavier than the four million solar masses, and it is assumed that this black hole has maintained its gravitational field and absorbing everything that comes in its vicinity. Types of Black Holes Due to this ability of black holes to soak up everything in its reach, black holes continue to expand and change their sizes. Scientists believe that besides gas, black holes easily soak up interstellar particles within their reach that subsequently results in a heavier black hole, which has become a characteristic to differentiate various type of black holes (Melia, 2003). Particularly, analysis has indicated three major characteristics that differentiate black holes from each other despite their identical existence in the space: mass of the black hole, spin angle and speed, and its electric charge (Melia, 2003). Scientists do not have the tools to observe and inspect black holes; however, they have found an alternative way to measure mass of these holes by analyzing particles that are orbiting the holes, which allows the scientists to calculate estimated mass of the black holes. Based on this mass calculation, stellar-mass and super-massive are two basic types of the black holes (Raine & Edwin, 2010) where stellar-mass is a type that is little heavier than the Sun, whereas, super-massive black holes are objects heavier than the entire galaxy. Scientists have come up with various other types for black holes that fall in between the two mass categories, however, stellar-mass and super-massive types enjoy most of the significance. Besides, different scientific bodies have further divided these two types based on the spin axis of particular black holes that help determine their rotation speed; however, there are still contradictions among this assumption of black holes being in rotation. Few scientists argue that all the black holes rotate since stars are the former bodies of black holes, and all the stars rotate, and thus, all the black holes, which has not been an accepted theory for many. Hawking Radiation and its Effects Although it is assumed that black holes soak up everything coming in their reach and which resulted in their name, still, scientists believe that black holes discharge few very weak particles or energy in the space that is known as Hawking Radiation (Kaper & Woudt, 2001). However, since this radiation is very weak in nature, it is almost impossible to observe it directly from the earth. Still, there have been observations where scientists have observed flares near the black holes that are considered potential hawking emissions. In 2008, NASA launched its Fermi Gamma-ray Space Telescope (Raine & Edwin, 2010) to make an attempt to search these flares or flashes that would confirm these emissions from the black hole. Particularly, this radiation got its name from the British physicist Stephen Hawking that proposed this theoretical assumption in 1974 regarding black holes emitting radiation (Taylor & Wheeler, 2000). He predicted that when black holes absorb a particle, it releases an emission in return to balance the particle-antiparticle energy in its horizon. In other words, scientists viewed it as one particle being absorbed by the black hole while the other particle escaping the sphere, which comes out as the radiation from the hole. Particularly, scientists believe that whenever a black hole emits a particle, the particle has the negative energy, which means that Hawking radiation results in reduction of mass from the black hole according to theorem model of Stephen Hawking (Taylor & Wheeler, 2000). Detection of Black Holes As mentioned earlier, it is almost impossible to observe and learn about the events happening in the black hole, which has resulted in contradictions related to the concept of black holes. Still, scientists that believe in black holes detect these condensed space objects by studying other observable objects that are in reach of the black hole body. In this way, scientists have been successful in identifying a number of black hole bodies that absorb particles within its sphere and simultaneously, emits Hawking radiation. In 2000, Taylor and Wheeler (pg. 23) quoted, “the energy for the black hole may be the trapped gas, stars, and dust that are drawn into the hole. Gas that is drawn into a black hole spins down within the hole much similar to a whirlpool”, which is another way to detect a black hole. In 2008, the NASA with the help of a spectroscope, the Hubble Space Telescope (Raine & Edwin, 2010) observed this gas and spinning whirlpool near the opening to the hole that confirmed existence of these black holes. As a result, astronomers nowadays consider gas spinning and its whirlpool as the ‘black holes signature’, as it helps the scientists observe activities of these holes and learn more about them. For instance, with these tools, astronomers have claimed that a black hole at the core of a galaxy is said to have a mass equal to that of 3 billion Suns (Raine & Edwin, 2010). Vicinity of a Black Hole Although nobody has ever experienced going in the vicinity of a black hole, however, scientists and astronomers have always speculated through theories and models as what would happen in its vicinity. Based on these speculations and observations of particles surrounding the black holes, scientists believe that as soon as a particle gets into the even sphere of a black hole, the black body instantly soaks it up and for viewers on the earth; the particle disappears right away. According to Raine & Edwin (2010, pp. 73-76), “the behaviour of the sphere during this condition is a dissipative structure that is directly equivalent to that of a conductive flexible covering with friction as well as electrical resistance - the covering theory. This is not similar to other field theories such as electromagnetism, which have no friction or resistivity on the microscopic point, since they are time reversible.” As discussed earlier, the event sphere is also known as ‘no point of return’ which indicates that in the vicinity of the black hole, no particle, object, or energy is escapable and that has been the reason that no man has ever tried to experience going in the vicinity of a black hole. Analysis has also shown that black holes have the ability to not only soak up all the particles in its sphere but also at the same time, remove all its characteristics except its mass, which further limits human knowledge regarding the information of black hole’s vicinity (Raine & Edwin, 2010). An interesting assumption regarding black hole’s vicinity is that objects seem to slow down due to dilation of gravitational force in the surroundings of black hole. In other words, a clock closer to the black hole will tick slower in comparison to clock at a greater distance to the black hole. From this understanding, although black hole soaks up every particle but as soon as a particle comes near the black hole, it decelerates and takes a huge amount of time to get into the hole, which is reverse to what actually happens at the earth when some force soaks up particles. Thus, this characteristic of black hole is against the physics laws and thus, various scientists do not agree to these assumptions, and only quantum physics and mechanics seem to accept some of these assumptions related to the black holes (Raine & Edwin, 2010). In this regard, astronomers believe that when a person will be entering into the black hole, he/she will not even notice the entrance and the entering period due to deceleration mode and at the same time, the person will not be able to avoid being carried away into the static black hole. Conclusion Particularly, this paper included discussion on some of the significance aspects of black holes that, despite of huge amount of research, have still remain a matter of confusion for scientists and astronomers worldwide. The paper included basic understanding of the black holes and the process of their evolution and formation. The paper also attempted to understand different types of black holes and their relativity with Hawking radiation. Lastly, the paper discussed the ways with which scientists detect these black holes and finally, included assumptions regarding experience within the vicinity of the black hole. It is an expectation that the paper will be beneficial for students in better understanding of the topic. References Kaper, L. and Woudt, P. A. (2001). Black Holes in Binaries and Galactic Nuclei. Springer. Melia, F. (2003). The Black Hole at the Center of Our Galaxy. Princeton University Press. Melia, F. (2003). The Edge of Infinity: Supermassive Black Holes in the Universe. Cambridge University Press. Raine, D. and Edwin, T. (2010). Black Holes: An Introduction. Imperial College Press. Susskind, L. and Lindesay, J. (2004). An Introduction to Black Holes, Information and the String Theory Revolution: The Holographic Universe. World Scientific Publishing Company. Taylor, E. F. and Wheeler, J. A. (2000). Exploring Black Holes: Introduction to General Relativity. Addison Wesley Longman. Read More