Black Holes Essays - Black Holes, Event Horizon,

Black Holes stence. The Search for Black Holes: Both As A Concept And An Understanding For ages people have been determined to explicate on everything. Our search for explanation rests only when there is a lack of questions. Our skies hold infinite quandaries, so the quest for answers will, as a result, also be infinite. Since its inception, Astronomy as a science speculated heavily upon discovery, and only came to concrete conclusions later with closer inspection. Aspects of the skies which at one time seemed like reasonable explanations are now laughed at as egotistical ventures. Time has shown that as better instrumentation was developed, more accurate understanding was attained. Now it seems, as we advance on scientific frontiers, the new quest of the heavens is to find and explain the phenomenom known as a black hole. The goal of this paper is to explain how the concept of a black hole came about, and give some insight on how black holes are formed and might be tracked down in our more technologically advanced future. Gaining an understanding of a black hole allows for a greater understanding of the concept of spacetime and maybe give us a grasp of both science fiction and science fact. Hopefully, all the clarification will come by the close of this essay. A black hole is probably one of the most misunderstood ideas among people outside of the astronomical and physical communities. Before an understanding of how it is formed can take place, a bit of an introduction to stars is necessary. This will shed light (no pun intended) on the black hole philosophy. A star is an enormous fire ball, fueled by a nuclear reaction at its core which produces massive amounts of heat and pressure. It is formed when two or more enormous gaseous clouds come together which forms the core, and as an aftereffect the conversion, due to that impact, of huge amounts of energy from the two clouds. The clouds come together with a great enough force, that a nuclear reaction ensues. This type of energy is created by fusion wherein the atoms are forced together to form a new one. In turn, heat in excess of millions of degrees farenheit are produced. This activity goes on for eons until the point at which the nuclear fuel is exhausted. Here is where things get interesting. For the entire life of the star, the nuclear reaction at its core produced an enormous outward force. Interestingly enough, an exactly equal force, namely gravity, was pushing inward toward the center. The equilibrium of the two forces allowed the star to maintain its shape and not break away nor collapse. Eventually, the fuel for the star runs out, and it this point, the outward force is overpowered by the gravitational force, and the object caves in on itself. This is a gigantic implosion. Depending on the original and final mass of the star, several things might occur. A usual result of such an implosion is a star known as a white dwarf. This star has been pressed together to form a much more massive object. It is said that a teaspoon of matter off a white dwarf would weigh 2-4 tons. Upon the first discovery of a white dwarf, a debate arose as to how far a star can collapse. And in the 1920's two leading astrophysicists, Subrahmanyan Chandrasekgar and Sir Arthur Eddington came up with different conclusions. Chandrasekhar looked at the relations of mass to radius of the star, and concluded an upper limit beyond which collapse would result in something called a neutron star. This limit of 1.4 solar masses was an accurate measurement and in 1983, the Nobel committee recognized his work and awarded him their prize in Physics. The white dwarf is massive, but not as massive as the next order of imploded star known as a neutron star. Often as the nuclear fuel is burned out, the star will begin to shed its matter in an explosion called a supernovae. When this occurs the star loses an enormous amount of mass, but that which is left behind, if greater than 1.4 solar masses, is a densely packed ball of neutrons. This star is so

Four Criteria for Identifying a Rock

Four Criteria for Identifying a Rock What is a rock, exactly? After some thought and discussion, most people will agree that rocks are more or less hard solids, of natural origin and made of minerals. But to geologists, all of those criteria have exceptions. Are All Rocks Hard? Not necessarily. Some common rocks can be scratched with your fingernails such as shale, soapstone, gypsum rock, and peat. Others may be soft in the ground, but they harden once they spend time in the air (and vice versa). And there is an imperceptible gradation between consolidated rocks and unconsolidated sediments. Indeed, geologists name and map many formations that dont consist of rock at all. This is why geologists refer to work with igneous and metamorphic rocks as hard-rock geology, opposed to sedimentary petrology. Are All Rocks Solid? Some rocks are far from completely solid. Many rocks include water in their pore spaces. Many geodes   hollow objects found in limestone country hold water inside them like coconuts. Two rocks that are barely solids include fine lava threads known as  Peles hair  and the fine open meshwork of exploded lava reticulite. Then theres the matter of temperature. Mercury is a liquid metal at room temperature (and down to -40 F), and petroleum is a fluid unless its asphalt erupted into cold ocean water. And good old ice meets all the criteria of rock-hood too...in permafrost and in glaciers. Are All Rocks Natural? Not entirely. The longer humans stay on this planet, the more that concrete accumulates. Concrete is a mixture of sand and pebbles (aggregate) and a mineral glue (cement) of calcium silicate compounds. It is a synthetic conglomerate, and it acts just like the natural rock, turning up in riverbeds and on beaches. Some of it has entered the rock cycle to be discovered by future geologists. Brick, too, is an artificial rock in this case, an artificial form of massive slate. Another human product that closely resembles rock is slag, the byproduct of metal smelting. Slag is a complex mixture of oxides that has many uses including road-building and concrete aggregate. It has found its way into sedimentary rocks already. Are All Rocks Made of Minerals? Many are not. Minerals are inorganic compounds with chemical formulas and mineral names such as quartz or pyrite. Coal is made of organic material, not minerals. The various types of stuff in coal are instead called macerals. Similarly, what about coquina...a rock made entirely of seashells? Shells are made of mineral matter, but they arent minerals any more than teeth are. Finally, we have the exception of obsidian. Obsidian is a rock glass, in which little or none of its material has gathered into crystals. It is an undifferentiated mass of geological material, rather like slag but not as colorful. While obsidian has no minerals in it per se, it is unquestionably a rock.