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Nedeľa, 15. decembra 2019
Science
Dátum pridania: 19.05.2005 Oznámkuj: 12345
Autor referátu: lucillie
 
Jazyk: Angličtina Počet slov: 567
Referát vhodný pre: Gymnázium Počet A4: 2
Priemerná známka: 2.99 Rýchle čítanie: 3m 20s
Pomalé čítanie: 5m 0s
 
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 processes for getting food and shelter depends on comlex technological systems. At present, modern industry largely depends on power, materials, machinery and production precesses.Muscle power was the only power available in early human history augmented by primitive tools, such as wedge or lever. The invention of wheel was followed by the watermill and windmill. The steam engine developed by J.Watt in 18th cent. 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. M. Faraday’s demonstration of dynamo in 1831 revealed the potential of the electical motor. Electricity was available from the early 1880s and was used for electric motors. Electicity is the most useful form of energy, convertible into heat and light and used to power machines.  in 1879 the american inventor T.A.Edison invented an electric bulb. Invention of internal-combustion engine made transport faster and more comfortable. In 1940s – explosion of the first atomic bomb. Nuclear energy – natural gas, water power, oil and coal. 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, bronze andiron were used 6000 B.C and 1000 B.C.

The introduction of the blast furnace in the 15th cent. enabled cast iron to be extracted, but this process remained expensive until charcoal was substitued by coke in 1709. This change starts the Industrial Revolution. New materials were rubber, glass, leather, paper, brick, porcelain and later  new synthetic materials dyes, plastic and celluloid and still later drugs and synthetic fibres. This process still continues with the growth of genetic engineering which enabled the production of synthetic insulin and growth hormones. Production process also changed as much as power and materials. The lathe was not developed until 18th cent. when it was used to produce objects of great precision. The first attempts at automation were in 18th cent. when looms were controled automatically by punched cards. The first moving assembly line appeared in 1870. At present, electronic computers controll fully automated plants (robotics). Plenty of invention and discoveries have influenced and changed human life  aircraft, radio, television, telephone, X-ray machines, radar, hovercraft, electric welding, photographs, birth-control methods, test-tube babies, penicillin, vitamin C. The greatest impact on modern-day life had the transistor, integral circuit and laser.

Electronic and mikroelectronic industries, space research and genetic engineering probably represent the branches where progress will continue most rapidly.
Space flights represent a special application of modern technology and science.The first satellites were launched into orbit around Earth in 1957 by the Russian. In 1961 Soviet cosmonaut Y.Gagarin became the first human in space abroad the spacecraft Vostok 1. Manned missions to the Moon  Apollo 11. On 20th July 1969 the first people to step onto the Moon’s surface were Neil Armstrong and Edwin Aldrin. At present artificial satellites are used for scientic purposes, communications, weather forecasting and military purposes. Since 1960s  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 latest Ebola.
 
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