Effects of major inventions in 21st century

Aircraft.

On August 8, 1908, at a racetrack outside Paris, Wilbur Wright executed what was, for him, a routine flight: a smooth take-off banking into a couple of tight circles, ending in a perfect landing. The flight took less than two minutes, but it left spectators awestruck. While the combined talents of Wilbur and Orville Wright had produced the first plane capable of controlled flight, their distrust of others had almost cost them the credit for their invention.

Aero plane, heavier-than-air craft that is usually propelled mechanically and supported by the aerodynamic action of the air stream on fixed-wing surfaces. Other types of aircraft that are heavier than air include the glider or sailplane, which is similarly equipped with fixed-wing surfaces but is not self-propelled, and rotary-wing aircraft, which are mechanically driven and supported by overhead rotors, such as the Autogiro and Helicopters. Another type is the ornithopter, which is lifted and propelled by flapping wings. Toy-sized ornithopters have been developed, but large-scale experiments have been unsuccessful. For the history of heavier-than-air craft he STOL craft is an aeroplane that takes off and lands very steeply, thus requiring only a short runway. For a given payload, it is more efficient in terms of fuel consumption and power requirements than a VTOL craft. It is also capable of higher speeds and longer-range flights than a helicopter. In September 1999 a solar-powered aircraft completed its first test-flight in California. The aircraft has a wingspan of 75 m (247 ft) and flies without a pilot. In the future it is thought the plane could remain in continuous flight for up to six months at a time and would be employed for scientific tests and telecommunications projects. For lighter-than-air craft, see Airship; Balloon.

INTRODUCTION:Aeroplane, heavier-than-air craft that is usually propelled mechanically and supported by the aerodynamic action of the air stream on fixed-wing surfaces. Other types of aircraft that are heavier than air include the glider or sailplane, which is similarly equipped with fixed-wing surfaces but is not self-propelled, and rotary-wing aircraft, which are mechanically driven and supported by overhead rotors, such as the Autogiro and Helicopters. Another type is the ornithopter, which is lifted and propelled by flapping wings. Toy-sized ornithopters have been developed, but large-scale experiments have been unsuccessful. For the history of heavier-than-air craft, see Aviation.

AEROPLANE TYPES AND USES:Aeroplanes may be categorized according to function and field of operation into three main types: (1) commercial aircraft, including those for transport of passengers and cargo by scheduled and non-scheduled airlines; (2) military aircraft; and (3) utility or general aircraft, which include all types not included in the other two. The particular characteristics of each plane are determined by the nature of the services to be performed. Increasing specialization in usage has resulted in wide variation in design requirements.

EFFECTS OF AIR CRAFTS:

Noise Pollution:A major problem associated with supersonic aircraft is noise. Engine noise of supersonic transports is louder and more high-pitched than that of subsonic jets, already a serious annoyance to airfield workers and residents of communities near airports. Medical concern, moreover, has been expressed about the effect of sonic booms, which are produced when the shock waves from an aircraft in supersonic flight pass over the listener. The shock front that travels with the aircraft extends over large vertical distances and reaches the ground with an impact that sounds like an explosion, even if a plane flies at maximum altitude. The shock wave may be so severe that it breaks windows on the ground far beneath the plane. Attempts are being made by designers and manufacturers to reduce both engine noise and sonic booms with aircraft such as the British Aerospace BAe 146, which entered service in 1983, and is one of the world’s quietest jet airliners. Regulations prevent supersonic flight over populated areas.

Appellate court affronts that noisy, polluting craft have no place on country waters:Marine country banned the craft in 1999 due to deleterious effects on air and water quality ambient noise, wild life public safety. Several residents of west marine have reported jet skiers harassing the gray whales that rest and nest in Dillon beach.

Residential radon exposure and lung cancer: Residential radon exposure is the major source of exposure to ionising radiation in Sweden as well as in most other countries. A nation-wide study indicated that exposure to radon in dwellings is related to an increased risk of lung cancer. There was a strong interaction between radon and smoking and no clear excess risk could be observed among non-smokers. However, the number of non-smoking lung cancer cases was too small for a detailed risk estimation.

Acute effects on health by ambient air pollution: Recent epidemiological studies show that comparatively low concentrations of air pollution are associated with adverse health effects. For example, short-term exposure to fine particles, nitrogen dioxide and ozone has been related to lung function disturbances and respiratory symptoms at levels occurring in Sweden. Some studies show correlations between daily particulate levels in ambient air and mortality.

Population exposure to air pollutants as a basis for epidemiological studies:The exposure level for air pollutants of the general population is generally assessed using information from central rooftop monitoring stations. There is little knowledge of the validity on the individual level of such estimates.

TERRORISTS ATTACK WTC:

Sept 11 2001: Terrorist hijacks and crash two airliners into the World Trade Center in NEWYORK and bring down the 110 storey twin towers leaving 3,000 people dead. A plane also slams into the Pentagon destroying a portion. Two United Airlines planes are also hijacked and crashed leaving 266 people abroad dead.

This is the effect of invention on the precious human lives in 21stcentury.

Need of the hour:Today on the eve of the anniversary of plague that hit the US on September 11 and continuesto sweep in various forms. America or Arab, Islam cist or neo-liberalist –across the world, today that is what? I want to say: pain is not a cure for pain. Those who traffic in pain, those who glorify pain, those who justify pain, this is the people to distrust. I have only one human response to pain of any kind: Alleviate it.

Presented by

B. Shakul HameedIX A

P.GopinathIX A

M. VinothIX A

P. DennisIX A

T. Kamala KannanIX A

GUIDED BY

M. NIRMALA.