This essay will explain what a black hole is along with how black holes can be detected and how black holes are formed. Moreover, this essay will also provide evidence of the existence of black holes and locate where in the universe black holes occur. Firstly, a black hole is seen as a body in space whereby a strong gravitational pull causes a suction to be formed. The strength of the gravitational pull is so significant due to the different forms of matter being squeezed into a small hole which hence, creates pressure. The pull is described as “so large” as speeds such as light, which travels at approximately 299 metres per second, is unable to escape this powerful pull of gravity and nothing is able to escape past the black hole’s boundary called the event horizon (Irshad, S., 2009). The event horizon is approximately 30 kilometres in diameter; there is no return past this. As a result of this, this conveys that many other objects in space such as dying stars or planets can easily disappear in black holes; nothing is seen to be able to escape a black hole therefore, because of this there is no information which has currently been gathered by man. However, with recent advance in technology, there may be missions in the nearest future to examine and retrieve further data and information on black holes. Research and observations made by astronomers such as Karl Schwarzschild (Barnes, D) show that black holes form due to dying stars whereby it collapses to the point where there is zero volume and infinite density, this is also known as singularity, a collapsed core (Smith, H. R.). Black holes are also able to merge with other black holes to form a super massive black hole, this is present in the centres of most galaxies (Wikipedia). Source: Cambridge Relativity
The process at which black holes are made simply only involve the cores of stars. The size of the core of the star is essential in determining whether a dying star will form into a black hole, a white dwarf or a neutron star. Cores of stars approximately three times the mass of the Sun form into black holes, this is done by fusion reactions in the star’s core produce such high flux neutrinos, which is similar to an electron however, does not carry a charge, and is carried away from its core (Casper, D). Subsequently, a greater number of neutrinos are produced which thus, causes the core to collapse, contract and temperature to increase due to trapped reactions and the density to increase sharply to a point where the neutrinos are unable to escape (Astronomy Cafe). The stored energy is not able to be released which causes the star to explode and a reverse shock occurs therefore, compressing the stars core “beyond the ability to support itself” (Astronomy Cafe); a black hole is created. There are two kinds of black holes, Schwarzschild, the non-rotating black hole, and Kerr, the rotating black hole. The non-rotating black hole is the simplest kind; this is when the core does not rotate and where it possesses only singularity and an event horizon. A Kerr is however, the black hole which occurs most frequently; this is when the core does rotate because the star in which it was formed by was already rotating. A Kerr black hole has the same properties as a Schwarzschild black hole like singularity and an event horizon along with ergosphere and static limit. Ergosphere may be defined as the area which surrounds the rotating event horizon which is egg-shaped. This space is usually distorted due to the spinning black hole whereby it almost carries a trail. Lastly, static limit is seen as the boundary between normal space and the ergosphere. An object may be rejected from the black hole as it has gained energy from the spinning or the black hole, however if the object crosses the event horizon, it will be the same as all other black holes, be sucked in and never be able to escape (Freudenrich). Black holes are invisible to the naked eye, the ways in which black holes may be...
References: Barnes, Daniel, 2005, University of Alaska Fairbanks, Accessed 10th May 2012,
Miller, Chris, 2003, Eclipse, Accessed 13th May 2012, <http://www.eclipse.net/~cmmiller/BH/blkform.html>
Please join StudyMode to read the full document