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Black Holes Essay

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Physical Science Lecture


        

                                                            Black Hole

The universe that we live in is so diverse and unique, and it interests us to learn about all the variance that lies beyond our grasp (“Black Holes Essay”). With the marvel of wonders, our lovely universe holds a mystery that is very difficult to understand because of the complications that arise when trying to examine and explore the principles of space. Ever watched the television show “Strange Days at Blake Holsey High.”  If not well, you truly missed out. That show was my first introduction to a Black Hole. They called the school Black Hole High. The serect of the world seems to be that of the ever elusive, black hole.

You may ask what is A black hole? Well, it is a theoretical entity predicted by the equations of general relativity (Jones). Black holes have never been directly observed, though predictions of their effects have matched observations (Www.articulatelogic.com). A black hole is a spot in space where the gravity pulls that a light cant even get out. The term “black hole” was not founded until 1967 when a physicist named John Wheeler was doing his homework on Einstein’s theories on general relativity “which showed that when a massive star dies, it leaves behind a small, dense remnant core” whose mass must be more than at least three times the mass of our sun. A light can't even escape a black hole, scientists are unable to observe black holes directly and must resort to indirect measurement to observe the supermassive object. Absolutely nothing in the known universe can survive in or escape from a black hole, so it can be said logically that time is stopped within the event horizon. The only way for an object to escape this fate would be for a strange anomaly to occur in the fabric of space, caused by a theoretically different type of black

hole (“Dr. K S Sibi, Physics”). If the mathematics that describe a black hole are reversed, the outcome is an object called a white hole (Bunn, Black Holes FAQ). As the complete opposite of a black hole, a white hole is an object into which nothing can fall and objects are only spit out (Bunn, Black Holes FAQ). At  this point, white holes are strictly theory. Their existence is highly improbable, the laws of physics break down, including Einstein's Theory of General Relativity; this is known also known as Quantum Gravity. Space and time can be broken apart and cause and effect cannot be unraveled. Even in todays world there is no satisfactory theory for what happens at and beyond the rim of the singularity. It is impossible to distinguish between a black hole and a neutron star unless we can prove that the mass of the unseen component is too great for a neutron star (“What Is a Black Hole?”).

A black hole can be formed  when 5 solar masses runs out of energy fuel, and the outer layers of gas is thrown out in a supernova explosion. The core of the star collapses to a super dense neutron star or a Black Hole where even the atomic nuclei are squeezed together (“ Black Holes”). A black holes radius becomes smaller than the Schwarzschild radius, which defines the horizon of the Black Hole: The death explosion of a massive star, resulting in a sharp increase in brightness followed by a gradual fading. At peak of a lights output, supernova explosions can outshine a galaxy. The outer layers of a exploding star is blasted out in a radioactive cloud. This expanding cloud, is visible way long after the initial explosion fades from the view, forms a supernova, explosions can outshine a galaxy. So, a black hole is an object, which is so compact that the escape velocity from its surface is greater than the speed of light.  A black hole masses ranging from 4 to 15 Suns (1 solar mass = 1 Msun = 2 x 1033 grams.) And are believed to be formed during supernova explosions. The after-effects are observed in some X-ray binaries known as black hole candidates

In the early 1900s, physicists Subrahmanyan Chandrasekhar concluded that any star more massive than 1 (A).44 solar masses (the Chandrasekhar limit) must collapse under general relativity. noble Physicist Arthur Eddington had a believe that some property would prevent the collapse. Both were righted, in their own way. Robert Oppenheimer predicted in 1939 that a supermassive star could collapse, therefore forming a "frozen star" in nature, rather than just in mathematics (“What Is a Black Hole?”). This collapse would seem to slow down, freezing in time at the point it crosses. The light from the star would experience a heavy redshift. Many of the physicists would considered this to only be a feature of the highly symmetrical nature of the Schwartzchild metric, believing that in nature such a collapse would not actually take place due to asymmetries. 1967 - nearly 50 years after the discovery of  - that physicists Stephen Hawking and Roger Penrose showed that not only were black holes a direct result of general relativity, but also that there was no way of halting such a collapse. Upon the  discovery of the pulsars supported this theory and, shortly thereafter, physicist John Wheeler coined the term (Jones) "black hole" for the phenomenon in a December 29, 1967 lecture. Outstanding work has included the discovery of Hawking radiation, in which black holes can emit radiation.

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