Science and Technolgy
Kategorie: Angličtina (celkem: 879 referátů a seminárek)
Informace o referátu:
- Přidal/a: anonymous
- Datum přidání: 01. července 2007
- Zobrazeno: 1893×
Příbuzná témata
Science and Technolgy
From the beginning of people's existence they have used tools, various types of energy and materials, generally for the purposes of production of nearly everything in our world. Almost every human process s for getting food and shelter depends on complex technological systems. At present, modem industry largely depends on power, materials, machinery and production processes. In early human history, the only power available was muscle power augmented by primitive tools, such as the wedge or lever. The invention of the wheel (about 300 B.C.) was followed by the watermill and windmill (12th cent. A.D.). Not until the 18th century did an alterative source of power appear in the form of the first working steam engine developed and improved by James Watt. The steam engine and other technical advances made possible the replacement of traditional agrarian economy by one dominated by machinery and manufacturing. The sudden acceleration of technical and economic development that began in Britain in the second half of the 18th century is called the Industrial Revolution. This transferred the balance of political power from the landowner to the industrial capitalist and created an urban working class. The steam engine was originally developed for draining mines but was rapidly put to use in factories and on the railways. Hand-made products were replaced by machine-made products which increased in number, and together with faster transportation by means of a railway, this meant a significant change in industry. Michael Faraday's demonstration of the dynamo in 1831 revealed the potential of the electrical motor and became the basis of electrical engineering. Electricity generated on a commercial scale was available from the early 1880s and was used for electric Qlotors which powered all kinds of machinery and for lighting, first by carbon arc lamp, invented by František Křižík 1880, and byan electric bulb invented by Thomas A. Edison in 1879. Electricity is the most useful and most convenient form of energy, readily convertible into heat and light and used to power machines. Electricity can be generated in one place (power stations/plants) and distributed anywhere because it readily flows through wires. The invention of the internal-combustion engine by German scientist Nicholas Otto in 1876 enabled two Germans, Gottlieb Daimler and Karl Benz to create the first petrol-driven motorcar (1885).This invention made transport faster and more comfortable and significantly shortened travel time. The 1940s saw the explosion of the first atomic bomb and the subsequent development of the nuclear power industry. Nuclear energy as well as natural gas, water power, oil and coal are current sources of energy. Scientists try to increase the contribution of wind, tidal, solar and geothermic power. The earliest materials used by humans were wood, bone, horn shell and stone. Metals were rare and difficult to obtain, although forms of bronze and iron were used in 6 000 B.C. and I 000 B.C. The introduction of the blast furnace in the 15th century enabled cast iron to be extracted, but this process remained expensive until charcoal was substituted by coke in 1709. This change ensured a plentiful supply of cheap iron at the start of the Industrial Revolution. Soon new materials were introduced, such as rubber, glass, leather, paper, bricks and porcelain and later, after the mid-1880s, entirely new synthetic materials appeared. First dyes, then plastic and celluloid and still later drugs were synthesized and synthetic fibres were made. This process still continues with the growth of genetic engineering which enabled the production of synthetic insulin and growth hormones. Production process and equipment in the factories also changed as much as power and materials. The lathe (potter's wheel), known in antiquity, was not fully developed until the 18th century when it was used to produce objects of great precision. The first attempts at automation were demonstrated in the 18th century when looms were controlled automatically by punched cards. The first moving assembly line appeared in 1870 in meat-packing factories in Chicago II, USA, and then in the motor industry in 1913. At present, electronic computers control fully automated plants (robotics). Plenty of inventions and discoveries have influenced and changed human life, such as aircraft, radio, television, telephone, X-ray machines, radar, air-cushion vehicles (hovercraft), electric welding, photographs, birth-control methods, test-rube babies, penicillin and vitamin C. Undoubtedly the transistor, integrated circuit (silicon chip) and laser were the three inventions that have had the greatest impact on modern-darn life. Electronic and microelectronic industries, space research and genetic engineering probably represent the branches where progress will continue most rapidly. Space flights represent a special application of modem technology and science.
The first satellites were launched into orbit around Earth in 1957 by the Russians and soon the first man-operated spacecraft was
put into orbit. In 1961 Soviet cosmonaut Yuri Gagarin became the first human in space aboard the spacecraft Vostock 1. In a few years manned missions to the Moon were achieved, the first being Apollo 11. The first people to step onto the Moon's surface on 20th July 1969 were Neil Armstrong and Edwin Aldrin. At present artificial satellites are used for scientist purposes, communications, weather forecasting and military purposes. Since the 1960s we have spoken about the scientific-technical revolution because at present both science and technology are the most important phenomena which can contribute to solving the problems of people on the earth: to find other alternative energy sources, to reduce pollution of all kinds and protect the environment, to find ways how to feed the constantly increasing number of people and to discover medicine against such diseases as cancer, AIDS or the latest Ebola virus which threaten the contemporary world. Not all inventions and discoveries, however, have brought people improvement and innovation. Ballistic missiles, extra powerful laser weapons, nuclear and H-bombs and pollution of the environment are only a few examples of how good ideas may be abused. Technology is dependent upon how people use it, under what circumstances new ideas and inventions are introduced into life.