The Role of Black Holes in the centers of Galaxies Essay

The Role of Black Holes in the centers of Galaxies - Essay Example In the Milky Way, the supermassive black hole is known as Sagitarrius A*, which is read as â€Å"A-star† (Naeye & Gutro, 2008). Sagitarrius A* is known to be â€Å"27,000 light years from the Earth [and] is four million times bigger than the Sun† (Ghosh, 2012). However, NASA reports Sagitarrius A* to be 26,000 light years away from the Earth, and not 27,000 (â€Å"A Mystery,† 2002). In fact, the existence of black holes has long been theorized by British astronomer Sir Martin Rees in 1974 and, according to him, â€Å"Supermassive black holes [or] ones with a million or even a billion solar masses might exist within the centers of some galaxies† (â€Å"A Mystery,† 2002). According to Durham University astrophysicist Ian Small, â€Å"The black holes [that we studied] are seen precisely at the point where they can have the most influence on the properties of the galaxies they reside in† (qtd. In Lovgren, 2005). This means that if the supermassiv e black holes are located at other points in the galaxy except the center, then it cannot exert equal influence on all parts of the galaxy. In short, for it to exert an almost equal gravitational force on every part of the galaxy, then it has to be at its center. The same principle works if the supermassive black hole is to release energy towards every part of the galaxy it is in, but this release of energy is merely hypothetical. According to Professor Richard Genzel of the Max Planck Institute for Extraterrestrial Physics, â€Å"The center of the galaxy was a â€Å"unique laboratory for the study of the strong gravity, stellar dynamics and star formation with a level of detail ‘never possible beyond our galaxy’† (qtd. in â€Å"Black hole,† 2008). This means that there must be one good reason for the supermassive black hole to eventually reside in the galactic center other than position. Genzel’s hypothesis is therefore the possibility that the ph ysics of the center of the galaxy is unusually different from the rest of its parts. Perhaps then there is a much stronger gravitational attraction as well as different principles of stellar dynamics and star formation towards the galactic center. Furthermore, according to Cain, the center of the galaxy, where the supermassive black holes reside, serves as the place where â€Å"every galaxy serves to focus and concentrate material as the galaxy was first forming† and it is also possible that this is the same exact point â€Å"where the black hole formed first, and collected the rest of the galaxy around it† (Cain, 2008). The aforementioned statement means that the possible origin of the galaxy may in fact be the exact point where the supermassive black hole is located and perhaps the galaxy still continues to grow from that central point. The implication of this theory is that, if it is true, then much constructive material is located in the black hole and that the gal axy is in fact never growing old and its parts constantly being replaced by these materials from the black hole. Another observation of Lovgren (2005) is that, according to scientists, â€Å"pairs of galaxies – and their black holes often merge together [thus producing] tidal forces [that] drive a lot of gas toward the center of the

Bloodsworth v. State 76 Md.App.23,543 A.2d 382 Research Paper

Bloodsworth v. State 76 Md.App.23,543 A.2d 382 - Research Paper Example Though Bloodsworth did have an idea of the actual person who committed the crime, he thought about ways to prove his innocence. It was until 1992 that Bloodsworth introduced the idea of DNA testing, which together with lawyer Bob Morin he pushed for consideration as part of the evidence. Findings by Edward Blake of the Forensic Science Associates (FSA) in April of 1993 excluded Bloodsworth. Similar tests conducted by FBI to determine correctness of the tests of FSA showed a mismatch between the DNA in the examined underwear of the victim and that of Bloodsworth (McNamara, 2009). The state then moved quickly to dismiss the charges, and the court approved $300,000 compensation to Bloodsworth for lost earning during the detention. The case is important considering that it was the first to apply DNA test to exonerate a suspect. In this case, the court did great in the admissibility of the forensic science evidence to determine the truth. Dawn Hamilton, a 9 years old girl visiting her father during summer in 1984 missed when searching for her cousin Lisa near their residence in Rosedale, Maryland. Someone approached Dawn and offered to help in the search into nearby forest wood where the investigators found a mutilated body of Dawn. Two boys who were fishing in a nearby lake saw the man move with Dawn into the wood. After discovery of the body, the two boys assisted the police into recreating a composite of the appearance of the suspect. Upon publication of the composite, someone claimed that image resembled Kirk Bloodsworth. The police move to present the picture of Bloodsworth to the boys for identification. One boy could not link the picture with the suspect they saw. Another claimed that the picture resembled the suspect but there was a problem with the hair. Nonetheless, police obtained arrest warrant and arrested

Science and Technology Essay Example | Topics and Well Written Essays - 500 words

Science and Technology - Essay Example Virtualization is one of the most essential concepts that will continue to play a dramatic role in the modern century. The problem that majority companies faced with the traditional IT infrastructure consists of several problems. One of the critical problems is the fact that it takes high energy costs. In addition, the traditional mainframe networks take too much space. Furthermore, the heat that is generated through these servers must be cooled. In fact, recent studies have found that organizations achieved on average an 18% reduction in their budget from cloud computing and a 16% reduction in data costs. Hence, virtualization should be embraced by organizations because it is cost-effective, flexible, and provides safe process of security protocols. Not only does virtualization allow corporations to be more â€Å"eco-friendly† but it also reduces costs which is crucial for success in the 21st century. Another main initiative that has been taken by both moguls is to introduce carbon .One of the high focal points that has been emphasized over the years as an alternative approach for energy source has been solar energy. A solar initiative can be a very robust solution that can be utilized for powering residential and industrial purposes. One of the many advantages that solar energy offer is substantial reduction in pollution since no waste product is yielded. The production of energy is being derived from use of fossil fuel. Another great facet that solar energy offers is the fact that it can harness electricity in remote locations. Undoubtedly, this provides flexibility and a seamless integration with the nation’s future technology roadmap. Embedding solar panels in remote location are cost-effective and can create a channel for an optimized energy production. The thought of an environment in which sun energy is utilized to power the communities and the nation’s infra structure can certainly be a reality. Although this innovative approach has been

How concerns of commerce and business spur on the development of Essay

How concerns of commerce and business spur on the development of mathematics - Essay Example The term mathematic was derived from the Greek word mathema to mean an instructional subject. Mathematical methods were further refined by Greek mathematics and that lead to expansion of the subject matter. The value system was a contribution by Chinese mathematics whereas the numeral system and its operational rules were from the Hindu (Kline 200). The roots of mathematics lie within the concepts of magnitude, number and form. The number concept has been gradually evolving with time and has lots of support from languages existence that provide distinction between numbers like one and two or many (Menninger 77). The most ancient demonstration of prime numbers and sequences is thought to have been from the Ishango bone, which was found in Congo near the Nile river headwaters (Avner 87). That bone was approximately 20,000 years old and it had a series of carved tally marks running in three columns as per the bone length. There are arguments that the prime number concept came after divi sion concept. It has also been claimed that, geometric designs were represented pictorially in 5th millennium BC. Other geometric ideas like ellipses, circles and Pythagorean triples were incorporated in England and Scotland monuments (Menninger 77). The history of mathematics is explained further by the contribution of different countries believed to have been involved in its development. Babylonian mathematics defines mathematics of Sumerians, people from Mesopotamia (Hoyningen et al. 42). Its name relates with Babylon’s central role of study. Sumerians who drafted tables of multiplication on clay tablets, solved division problems and geometrical exercises evidenced written mathematics (Avner 87). Most of the clay tablets that were recovered included cubic and quadratic equations, fractions, algebra and calculations of pairs of regular reciprocal. Quadratic and linear equations solutions were also included. Egyptian mathematics is defined as mathematics in Egyptian language (Avner 87). The Rhind papyrus is its extensive text and it is a manual of instructions for students in geometry and arithmetic. It gives multiplication methods, area formulas, working out unit fractions and division. It also shows knowledge of composite, prime numbers, and arithmetic. It also describes how geometric series and linear equations are solved (Hoyningen et al. 42). Greek mathematics is also called Hellenistic mathematics. It was more complicated than other mathematical genres. Others used inductive reasoning and repeated observations for rule establishment but Greeks used deductive reasoning (Mumford 105). Calculations of volumes and areas of curvilinear figures were introduced and great advancement in geometry reached. The Euclidean geometry theorem introduced subjects of the time as algebra, number theorem and solid geometry (Kline 200).This theorem proved infinity of many prime numbers and the irrationality of the square root of two. This theorem was also thorough on subjects such as optics, conic sections, mechanics and spherical geometry (Hoyningen et al. 42). In Chinese and Middle Eastern advances, there was pie estimation by circumscribed and inscribed polygons. They were also particular in notation of the decimal system, development of the Chinese algebra and

Electronic frontier Assignment Example | Topics and Well Written Essays - 250 words

Electronic frontier - Assignment Example The giants who own the market in the digital world try to kill any competition that they get but this can no longer be done as I can simply challenge any of the plea with the use of the EFF. With the help of the organization I can make sure that my circle of privacy is not violated by the state authorities. I can make a fine line when I want to be anonymous on the internet and express my views accordingly. With the help of EFF I believe that I can challenge anyone who finds my anonymity illegal or tries to find my identity and threaten me in any case. If I find out that anyone is trespassing the line of my privacy I can always approach the organization and inform my government regarding the necessary issues so as to avoid any legal repercussions. I believe that I can protect my privacy to the fullest of extent if given the knowledge provided by the organization. The newest technology allows one to detect when anyone is trying malinger against you or is trying to impose something that I may not have even done. My information and logs should not be accessed by any given company unless they have issues of national security against

Networks classification Essay Example for Free

Networks classification Essay In the world of computers, networking is the practice of linking two or more computing devices together for the purpose of sharing data. Networks are built with a mix of computer hardware and computer software. Networking software applications are available to manage and monitor networks of all sizes, from the smallest home networks to the largest enterprise networks. Networks classification 1. Local Area Networks (LANs): These connect over a relatively small geographical are, typically connecting computers within a single office or building. In most cases they connect to a common electronic connection- commonly known as a network backbone. LANs can connect to other networks either directly or through a WAN or MAN. Most LANs connect workstations and personal computers. 2. Metropolitan Area Networks (MANs): These connect networks around a town or city. Short for Metropolitan Area Network, a data network designed for a town or city. In terms of geographic breadth, MANs are larger than local-area networks (LANs), but smaller than wide-area networks (WANs). An example of a Man is the Eastman (Edinburgh and Stirling MAN) network that connects universities and colleges. 3. Wide Area Networks (WANs) : These connect networks over a large geographical area, such as between different buildings, towns or even countries. 4. A campus area network (CAN) is a computer network made up of an interconnection of LANs within a limited geographical area. In the case of a university campus-based campus network, the network is likely to link a variety of campus buildings including, for example, academic colleges or departments, the university library, and student residence halls. 5. A personal area network (PAN) is a computer network used for communication among computer and different information technological devices close to one person. Some examples of devices that are used in a PAN are personal computers, printers, fax machines, telephones, PDAs, scanners, and even video game consoles. A PAN may include wired and wireless devices. The reach of a PAN typically extends to 10 meters Topology Network topology is the arrangement of the various elements (links, nodes, etc.) of a computer or biological network. Essentially, it is the topological structure of a network, and may be depicted physically or logically. There are two basic categories of network topologies: 1. Physical topology refers to the placement of the networks various components, including device location and cable installation, 2. logical topology shows how data flows within a network, regardless of its physical design. The study of network topology recognizes eight basic topologies: †¢ Point-to-point = the simplest topology is a permanent link between two endpoints. †¢ Bus = A linear bus topology consists of a main run of cable with a terminator at each end (See fig. 1). All nodes (file server, workstations, and peripherals) are connected to the linear cable. Advantages of a Linear Bus Topology †¢ Easy to connect a computer or peripheral to a linear bus. †¢ Requires less cable length than a star topology. Disadvantages of a Linear Bus Topology †¢ Entire network shuts down if there is a break in the main cable. †¢ Terminators are required at both ends of the backbone cable. †¢ Difficult to identify the problem if the entire network shuts down. †¢ Not meant to be used as a stand-alone solution in a large building. †¢ Star = A star topology is designed with each node (file server, workstations, and peripherals) connected directly to a central network hub, switch, or concentrator (See fig. 2). Data on a star network passes through the hub, switch, or concentrator before continuing to its destination. The hub, switch, or concentrator manages and controls all functions of the network. It also acts as a repeater for the data flow. This configuration is common with twisted pair cable; however, it can also be used with coaxial cable or fiber optic cable. Advantages of a Star Topology †¢ Easy to install and wire. †¢ No disruptions to the network when connecting or removing devices. †¢ Easy to detect faults and to remove parts. Disadvantages of a Star Topology †¢ Requires more cable length than a linear topology. †¢ If the hub, switch, or concentrator fails, nodes attached are disabled. †¢ More expensive than linear bus topologies because of the cost of the hubs, etc. †¢ Ring = A network topology that is set up in a circular fashion in which data travels around the ring in one direction and each device on the right acts as a repeater to keep the signal strong as it travels. Each device incorporates a receiver for the incoming signal and a transmitter to send the data on to the next device in the ring. The network is dependent on the ability of the signal to travel around the ring. When a device sends data, it must travel through each device on the ring until it reaches its destination. Every node is a critical link. †¢ Mesh = The value of fully meshed networks is proportional to the exponent of the number of subscribers, assuming that communicating groups of any two endpoints, up to and including all the endpoints Advantages of Mesh topology 1) Data can be transmitted from different devices simultaneously. This topology can withstand high traffic. 2) Even if one of the components fails there is always an alternative present. So data transfer doesn’t get affected. 3) Expansion and modification in topology can be done without disrupting other nodes. Disadvantages of Mesh topology 1) There are high chances of redundancy in many of the network connections. 2) Overall cost of this network is way too high as compared to other network topologies. 3) Set-up and maintenance of this topology is very difficult. Even administration of the network is tough. †¢ Tree = A tree topology combines characteristics of linear bus and star topologies. It consists of groups of star-configured workstations connected to a linear bus backbone cable (See fig. 3). Tree topologies allow for the expansion of an existing network, and enable schools to configure a network to meet their needs. Advantages of a Tree Topology †¢ Point-to-point wiring for individual segments. †¢ Supported by several hardware and software venders. Disadvantages of a Tree Topology †¢ Overall length of each segment is limited by the type of cabling used. †¢ If the backbone line breaks, the entire segment goes down. †¢ More difficult to configure and wire than other topologies. †¢ Hybrid = Hybrid networks use a combination of any two or more topologies in such a way that the resulting network does not exhibit one of the standard topologies (e.g., bus, star, ring, etc.). For example a tree network connected to a tree network is still a tree network topology. A hybrid topology is always produced when two different basic network topologies are connected. Two common examples for Hybrid network are: star, ring network and star bus network †¢ Daisy chain = Except for star-based networks, the easiest way to add more computers into a network is by daisy-chaining, or connecting each computer in series to the next. If a message is intended for a computer partway down the line, each system bounces it along in sequence until it reaches the destinati on. A daisy-chained network can take two basic forms: linear and ring. o The straight-through cables are used when connecting Data Terminating Equipment (DTE) to Data Communications Equipment (DCE), such as computers and routers to modems (gateways) or hubs (Ethernet Switches). The cross-over cables are used when connecting DTE to DTE, or DCE to DCE equipment; such as computer to computer, computer to router; or gateway to hub connections. The DTE equipment terminates the signal, while DCE equipment do not. †¢ RJ stands for Registered Jacks. These are used in telephone and data jack wiring registered with FCC. RJ-11 is a 6-position, 4-conductor jack used in telephone wiring, and RJ-45 is a 8-position, 8-conductor jack used in 10BaseT and 100BaseT Ethernet wiring. †¢ UTP stands for Unshielded Twisted Pair. It is the cabling system with one or more pairs of twisted insulated copper wires contained in a single sheath. It is the most widely used cabling system in telecommunications and data communications environment today.

Vietnamese Immigration to America Essay Example for Free

Vietnamese Immigration to America Essay Vietnam is located in the Southeastern Asia, bordering the Gulf of Thailand, Gulf of Tonkin, and South China Sea, alongside China, Laos, and Cambodia; 6 00 N, 106 00 E. Its Total Land Area is 329,560 sq km, with a land area of 325,360 sq km and water area of 4,200 sq km. It is slightly larger than New Mexico. Its total land boundary is 4,639 km with border countries like Cambodia, China and Laos. It has3, 444 km coastline which excludes the islands. Its maritime claims include the territorial sea: 12 nm, contiguous zone: 12 nm, exclusive economic zone: 200 nm, continental shelf: 200 nm or to the edge of the continental margin. Its climate tropical in south, monsoon in north with hot, rainy season and warm, dry season in mid-October to mid-March. Its terrain includes low, flat delta in south and north; central highlands; hilly, mountainous in far north and northwest. (See â€Å"Vietnam†. About: Geography). The history of Vietnamese Americans began with the end of the Viet Nam War in 1975. On 28 January 1973, after having spent years and millions of dollars financing the Viet Nam War, the United States government reluctantly agreed to withdraw its financial and military assistance after signing the Agreement on Ending the War and Restoring Peace in Viet Nam. The peace agreement was signed by representatives of the United States, the Republic of Viet Nam (South Viet Nam), and the Democratic Republic of Viet Nam (North Viet Nam) in Paris. The agreement committed the United States and other signatories to respect the independence, sovereignty, unity, and territorial integrity of Viet Nam, called for prisoners of war to be exchanged, and declared an in-place cease fire. Soon after the withdrawal of the United States military and economic support, the military situation deteriorated rapidly for the government of South Viet Nam. The flight of the Vietnamese refugees really began within the country, with the North Vietnamese military offensive of mid-March 1975 resulting in the defeats at Pleiku, Kontum, and Ban Me Thuot. As a result of this military offensive about one million refugees poured out of these areas and headed for Saigon and the coast. Most traveled by foot, few were fortunate enough to travel by car, truck, or motor bike. On 30 April 1975, the capital of South Viet Nam, and thus South Viet Nam, came under the control of the Provisional Revolutionary Government. This resulted in the flight of the Vietnamese refugees to the United States. Vietnamese refugees were not immigrants who chose to come to the U. S. for better political, social, and economic opportunities. Their migration was for the most part unplanned and out of desperation. Vietnamese emigration is generally divided into two periods, each with several â€Å"waves. † The first period began in April 1975 and continued through 1977. This period included the first three waves of Vietnamese refugees in the United States. The first wave of refugees, involving some ten to fifteen thousand people, began at least a week to ten days before the collapse of the government. The second wave, and probably the largest in numbers, involved some eighty thousand, who were evacuated by aircraft during the last days of April. The evacuation of American personnel, their dependents, and Vietnamese affiliated with them was achieved through giant helicopters under â€Å"Operation Frequent Wind. † These individuals were relatively well-educated, spoke some English, had some skills that were marketable, came from urban areas, and were westernized. Members of these two waves were primarily Vietnamese who worked for the U. S. government, American firms, or the Vietnamese government. All were thought to be prepared for life in the United States on the basis of their contact with the American government and association with Americans. The final wave during this period involved forty to sixty thousand people who left on their own in small boats, ships, and commandeered aircraft during the first two weeks of May 1975. They were later transferred to Subic Bay, Philippines and Guam Island after having been picked up, in many cases, by U. S. Navy and cargo ships standing off the coast. A second period of the Vietnamese refugee migration began in 1978. Since the fall of South Viet Nam in 1975, many Vietnamese have tried to escape the political oppression, the major social, and political and economic reforms instituted by the authoritarian government of North Viet Nam. Although the influx continues steadily, the numbers are no longer as massive as they once were. A significant characteristic of this period, especially between the years 1978 to 1980, is the large number of ethnic Chinese migrating out of Viet Nam and Cambodia. In addition to the ethnic Chinese, there were many Vietnamese who left during this period. These individuals have been called â€Å"boat people† because the majority of them escaped in homemade, poorly constructed boats and wooden vessels. Due to flimsy vessels, scant knowledge of navigational skills, limited amount of provisions, and numerous attacks by Thai sea pirates, the death rate of the â€Å"boat people† was and is very high. Many of the boat people are awaiting their fate in refugee camps throughout Southeast Asia. In addition, since 1979 many former receiving countries are turning away refugees because of the economic, political, and social strains that they are allegedly precipitating. (See â€Å"Vietnam War†. Wikipedia, the Free Encyclopedia). The areas where they settled after their migration were in the states of California, Texas, Louisiana, Washington, Virginia, Pennsylvania, and Florida. As a result of the original resettlement, the secondary migration process, and the length of time since their first arrival in 1975, Vietnamese refugees have been able to establish communities throughout the United States, but are generally located in metropolitan and urban areas. Since the Vietnamese were forced to leave their country as a result of the war, personal adjustments such as becoming proficient in English, separating from families, and dealing with war memories are pressing issues. Because many Vietnamese did not know English, learning a new and different language became an important criterion for adjusting to new living conditions in the United States. In addition, the Dispersal Policy forced many extended families to separate, and some Vietnamese have found themselves in new and unfamiliar communities without family or the community support networks which were of great importance in Viet Nam. Finally, because of the traumatic experiences incurred while leaving their homeland, many experience depression, anxiety, alienation, a sense of helplessness, and recurring war nightmares. To assimilate into the United States economically as quickly as possible, many Vietnamese were forced to obtain low paying jobs. Even for those who were professionals in their country, their credentials failed to transferor simply were not accepted in the United States. The large number of people who were members of the military had skills which were no longer marketable. And, because many did not have the necessary skills to find high paying jobs, both men and women have had to find employment. It is easier for women to find employment, especially in the service and low-skill sectors, and women began to occupy positions traditionally held by men. That is, women have succeeded in achieving a degree of economic independence through their employment outside the home. In some cases, women support the entire family while the men receive technical or educational training for occupations with specific skills. Family conflicts between husbands and wives resulted as an unfortunate side effect. Since women were more likely to find jobs than men and in some instances became the only income earner, traditional family roles and authority were changing. Men were no longer the sole provider for the family and their authority was no longer as clear as it was in Viet Nam. There were a number of substantial of Vietnamese who are attending prestigious colleges and universities throughout America. Upon graduation, these individuals have also become members of the professional group or skilled workers in America. However, while there has been some success in the field of education, Vietnamese Americans are not a â€Å"model minority. † After the fall of Viet Nam in 1975, only a small group of children continued their education. Many younger Vietnamese had problems adjusting to American school. Those who seemed to be having the most problems adjusting are those who came either as unaccompanied minors or the recent arrivals. These individuals primarily immigrated after 1975 and most likely came at an age when it was difficult to learn a new language and adjust to a new society; some have turned to gangs, drugs, gambling, and other illegal activities. The formation of youth gangs might have resulted from their inability to catch up with their peers in schools, their unfamiliarity with a strange land, and perhaps their alienation from their families due to cultural gaps. ( See â€Å"The New Migrants from Asia: Vietnamese in the United States†. Organization of American Historians).