Abstract This paper provides an overview of the Milky Way galaxy, named for the hazy band of light that stretches across the dark skies of the night. It looks at how, although this system (usually referred to as a spiral galaxy, much like the Andromeda galaxy) has created much wonder and awe since the beginning of human civilization, it was not until 1610 that its true nature was discovered by Galileo when he turned his small refracting telescope toward the night sky to reveal that the Milky Way was composed of countless individual stars, nebula and other astronomical bodies, many of which remained mysterious and unknown well into the 20th century.
From the Paper "Looking from the Earth at the Milky Way, one obtains two distinct views--first, in the direction of the poles, the density of the stars decreases dramatically, meaning that at the poles, the stars are far apart and are set against a very dark background. Second, looking along the equatorial plane, the closest stars are situated against a faint but luminous band, being "the blended light of billions of stars in the galaxy's disc. In 1785, astronomer William Herschel, by using a 48-inch reflector telescope of his own construction, counted the stars in more than 600 regions of the sky and concluded that "the majority are concentrated along a plane and that the galaxy is disc-shaped with the Sun at its center" (Parker, 1988, 156). "
Abstract This paper looks at black holes in terms of the most prevalent theories. It first, defines what we have come to understand as a black hole. It then touches upon how black holes are documented and measured. Thirdly, it examines the black hole believed to be at the center of our own Milky Way galaxy. Finally, it explores the prevalent hypothesis that black holes are in fact the genesis of all galaxies.
From the Paper "Gravity is the cause of black holes. A black hole is the unlimited and irresistible force of ultimate gravity in the universe. To understand how a black hole is created, it is helpful to understand a bit about the basics of gravity. Imagine shooting an arrow into the sky. The harder you shoot the arrow, the farther it will go in attempting to escape the pull of the Earth's gravity. If you were to use a big enough bow with enough force you could help the arrow reach speeds exceeding 7miles per second which is the escape velocity for the Earth. Escape velocity indicates the minimum speed necessary to beat the pull of the planet's gravitational core (Cowen , 390). The strength of the gravitational pull of the core is determined by the density and mass of the core. The denser and more massive that the core is, the greater the gravitational pull. If you were to drop a ball to the center of the earth, the gravitational forces would crush it into an ever shrinking volume requiring even greater amounts of force to help it reach escape velocity. As the greatest theoretical speed for any physical object in the universe is that of light (which travels at 186 thousand miles per second) a mass large and dense enough can actually exert so much force that not even light can achieve escape velocity. The object that can pull even light into it and keep it from escaping is a black hole."
Abstract This paper explains that by viewing the gas that surrounds stars as a dynamic atmosphere, undergoing cycles of materials similar to those that go on in the Earth's own protective gases, astronomers are understanding more and more about the processes involved in the formation of stars. The paper deals with the questions of how the supernova of massive stars affect the formation of stars in the future, why star formation seems to occur in relative bursts, and how long the Milky Way will continue to produce stars.
From the Paper "Beyond applying the atmospheric model to intergalactic gas, astronomers have also been studying more carefully exactly what components make up the gas and at what temperature these components exist. About 90% of the constituents of intergalactic atmosphere are various forms of hydrogen, with close to 10% being helium, and everything else, from lithium to uranium -- the whole spectrum of the periodic chart -- making up less than 0.1%. The majority of the hydrogen is present as neutral hydrogen, termed H I by astronomers. This form of hydrogen gas is identified by the spectral frequency of the light that it emits, namely 1,420 megahertz. Although scattered throughout the galaxy, the majority of H I is located around the galactic midplane, and forms a gaseous disk about 300 parsecs thick (Reynolds, 2002, p. 40)."
Abstract The process of star formation is a complex one that takes millions of years to complete. While there are many types and sizes of stars, all come from the same basic properties. From clouds of gas and dust to protostars to the Main Sequence, star birth is a process dependent upon many factors. This paper examines how stars are formed and the reasons behind the various colors of stars.
From the Paper "Stars use nuclear fusion to convert, generally, hydrogen to helium, a process called nucleosynthesis. Nucleosynthesis is the production of new elements via nuclear reactions. The mass of the star at the time of the nuclear fusion determines what types of nucleosynthesis are needed. For smaller stars, hydrogen is converted to helium. For mid sized stars, like the sun, helium is turned to oxygen and carbon, as the hydrogen supply burns out. For massive stars, as hydrogen becomes depleted, helium is turned to carbon and oxygen, which are then turned to neon, sodium, magnesium, sulfur and silicon. Later, those elements are transformed to elements like calcium, iron, nickel, chromium, copper, and other elements. It is this process of nuclear fusion and nucleosynthesis that allow stars, even massive, old stars, to continue to exist. It is this stage that is called the Main Sequence for a star (Enchanted Learning, 100)."
Abstract This paper covers Hubble's time and place in his scientific era, a compact biography and a brief explanation of his scientific achievements. It looks at how he discovered that there are more galaxies than just the Milky Way and how he tackled two of the most fundamental questions about the universe, its age and size.
From the Paper "Born in 1889, Edwin Hubble grew to be a very "large mass of ego," as author Bill Bryson states in A Short History of Nearly Everything (2003) (114). He was born in a small Missouri town on the edge of the Ozarks and grew up in Wheaton, Illinois; on the outskirts of Chicago. His father was a successful insurance executive, so life was always calm and Hubble abiding. Accordingly, Hubble was remarked to be a tough and poised athlete, charismatic, chic, and immensely good-looking-"handsome almost to a fault," in the words of William H. Cropper; as well as "an Adonis" in the words of another admirer (115). These fated gifts were used more or less in constant acts of valor-rescuing drowning swimmers, leading frightened men to safety across the battlefields of France, embarrassing world-champion boxers with knockdown punches in exhibition bouts."
Abstract This paper presents a review of "Ghosts of Mississippi", by Maryanne Vollers; "Sons of Mississippi", by Paul Hendrickson; "The White House Staff", by Bradley H. Patterson; and "The American Presidency", by Sidney M. Milkis and Michael Nelson. The first two books listed are about civil rights in the South and the second two are about the American presidency.
From the Paper "Maryanne Vollers introduces her text by stating that Byron De La Beckwith was not an ordinary prisoner and he was not treated like one. The subject of Vollers' book is the murder of civil rights activist of Medgar Evers by Byron De La Beck and the determined efforts of Myrlie Evers to bring Beck to justice -- an effort that took quite literally decades despite the fact that it was well known that Beck was Evers' killer."
Tags: political science, history, civil rights, public administration, presidency
