Archives May 2013

Distance education is a new trend of education which generally takes place when a teacher and student (s) are not face to face but are separated by physical distance and various electronic media are used to bridge the instructional gap. Before ten years this system or trend was not thought a goal means of education because 'to take degree' was not the sole aim of a student. Instead people thought that regular classes provided real knowledge to the students and therefore there should not exist any alternative of it. But with the progress of science electronic media, new electronic equipment, the situation has been changed. Through TV. Educational programmes, the correspondence education can be made to be understood in better way. Research comparing distance education to traditional face to face instruction indicates that teaching and studying at a distance can be as effective as traditional instruction, when the method and more...

“I see nothing in space as promising as the view from a Ferns wheel.” E.B. White, writer How do you outdo the Eiffel Tower? This was the problem facing the organizers of the Chicago World's Fair of 1893. The solution was presented by George Ferris (1859-1896), who submitted details right down to ticket prices. Ferris was a civil engineer with an interest in railroads and bridge building. His design was for a wheel, 262 feet (80 m) tall, capable of carrying 2,000 people up for a view of the whole fair. Smaller, wooden "pleasure wheels" had already appeared around the world, but this design was on a much grander scale. However, the fair organizers thought it could not be done and rejected Ferris. Not a man to be easily deterred, he returned after convincing fellow engineers to endorse the design and local investors to cover the $400,000 cost. This time more...

Mobile phone is the latest and wonderful invention. This instrument is very small in size but performs very big functions. It is in fact, an improvised version of the landline telephone and enables us to talk to anybody in any part of the world. It can be carried anywhere wherever a person may go. It makes conversation possible whether we are travelling by car, bus, train or aeroplane. This phone has received tremendous response from people all over the world. It is used by all people, whether rich or poor, in order to remain in constant touch with the other people associated to them. Almost all cities of the world are connected with mobile network. A mobile phone has played a very vital role, especially during an emergency such as an accident, a robbery, a murder or sudden serious illness. It has revolutionised the way we communicate. Today we find more...

Thermostats control the temperature of a system—such as an oven, car engine, or room—so that it remains close to a preset value. The control is achieved by means of a temperature-sensitive switch that operates heating or cooling devices. Many of these switches are activated by monitoring the expansion of metals, waxes, or gases. More recently, thermostatic devices have relied on thermistors in electrical circuits. The thermistor is usually a ceramic or polymer electrical resistance that changes its value significantly as a function of temperature. Thermistors were patented by Samuel Ruben in 1930. Dr. Andrew Ure (1778-1857) was a Scottish medic and chemist who was also greatly interested in the factory system, free trade, and steam-driven machines. Realizing that textile mills needed constant temperatures to ensure uniformity in product manufacture, Ure patented a thermostat for this purpose. This was not an entirely new device. The Dutchman Cornelis Drebbel (1572-1633) had used more...

Before the 1940s, scientists wanting to determine the age of fossils and other organic materials relied on relative dating techniques, grouping objects by the estimated date of surrounding rock strata. This method could produce large inaccuracies. Strangely, the ability to date objects more accurately was to originate from outer space. High- energy cosmic rays are constantly bombarding our atmosphere; when they hit, they break up atoms in the stratosphere. A consequence of this is the production of an unstable radioactive form of carbon called Carbon-14 (C-14) from atmospheric nitrogen. American scientist William Frank Libby (1908-1980) reasoned that, as all living creatures are made up of carbon and are constantly replacing this carbon from the atmosphere (plants take it in as carbon dioxide and animals absorb it from plants), all living organisms should have an equal amount of C-14 in their bodies in relation to the proportions occurring in the atmosphere. more...

Pollution is a world problem. Today, whatever little oxygen we inhale, is polluted. No doubt, most of our progress and development is the result of industrial growth and technological advancement of which we feel proud. But it has its evil effect too i.e. pollution. By pollution we mean to destroy the purity of a thing. It is generally used for natural environment i.e. land, water, air. Pollution makes the environment unfit for living. It becomes a health hazard. It brings many diseases, hence it must be checked soon. Land pollution is caused due to dumping and disposal of wastes, application of agro-chemicals in the soil. Deforestation also leads to land pollution. Hence it is necessary to start tree plantation as a social service and national programme. It is the only way which can save humanity. In India, wastes of oil, refineries and atomic plants are dumped into the rivers or more...

Science has made wonders in recent times. It has revolutionized the life in every field such as travel transport, communication, recreation, agriculture, industry, medicine, trade and commerce. We have electricity which has made our life comfortable in various ways. We have atom bomb, a great source of power. Now it is up to us whether we use science for good purposes or take undue advantage of it. No doubt science has placed in the hands of man extremely destructive weapons which may ruin the whole world in seconds but it never compels man nor creates a situation to make use of them. It is our greed and madness for power that urge us to use destructive weapons because we want to  finish each other. Undoubtedly science has contributed a lot towards world peace of which we must be obliged. Science has given quick means of transport and communication which help more...

A tailor sews clothes. He is found in every village and town. No civilized person can do without him. He is a very important member of our society. He earns his living by hard working. He knows no holiday. A tailor depends upon his tools. He requires a few tools. They are-a pair of scissors, a sewing machine, a measuring tape, a sharp needle, a thimble on his middle finger, some thread reels and balls, and an iron press, he puts on thimble on his middle finger to protect it from needle pricks. He also needs a wooden plank and a piece of coloured chalk and a register to note down the measurements of customers. These tools are very necessary for the tailor. He cannot do his work without them. If any one of these tools is missing he cannot do his work. A tailor's shop is generally seen in more...

"The American people never carry an umbrella. They prepare to walk in eternal sunshine." Alfred E. Smith, U.S. politician It was either the Chinese or the ancient Egyptians who first invented the umbrella. Early records from both cultures indicate that umbrellas were used to screen monarchs and people of high standing from the sun. The job of hoisting an umbrella above the emperor was often reserved for the servant of highest rank. The Chinese developed the technology furthest, waxing their paper parasols to provide protection from rain. Around 4,000 years ago, the Chinese also made their umbrellas collapsible, and since then the overall design has changed very little. Making its way to Rome and Greece, the umbrella was used to shade women and even effeminate men from the sun while attending the open-air theater. These umbrellas were made from leather or skins. The umbrella reached England during the reign of more...

Outline : Poor supply of water—many difficulties experienced— cleanliness cannot be maintained properly—fear of diseases spreading— even drinking water sometimes not available.   The problem of water supply in a big city like Delhi is quite acute. It reaches at alarming point during the summer months, when the water taps run dry. There is not a single drop of water. The Yamuna flows at its low level. The water comes just for a while. It leads to a lot of tension and quarrel especially in the streets where there are community taps. People form long queues with their pitchers, pails and buckets. They stand in wait for water for hours together. They are there right from early morning or even earlier. The low lying areas may have a little of water. But what about the houses and localities situated at high places ? There the water reaches very slowly even more...