Archives April 2013

The idea of an atom laser has been around for many years, and its principle is based on the more conventional optical laser. A normal laser emits light, but, unlike a normal lamp, the laser light is "coherent," so that it can focus to a pinpoint, and also travel a long distance without spreading out like a flashlight beam. By the time the optical laser was introduced in 1960, scientists were already familiar with the wavelike properties of matter, and the atom laser was under consideration as a theoretical possibility. But It was not until 1997 that reports of the first rudimentary working model were released. A bizarre form of supercooled matter called a Bose-Einstein condensate made it all possible. This strange stuff, in which individual atoms "lose their identity" and coalesce into a single "blob," is in some ways like the photons of light in a laser. It was more...

“... good wood block printing rests upon the perfection of drawing and painting, of color and line." Hiroshi Yoshida, Japanese Woodblock Printing (1939) Woodblock printing first appeared in China during the Tang Dynasty in the ninth century and was initially used in the production of textiles and Buddhist texts and amulets. A text or image was transferred to a thin layer of paper that was then glued face down onto a wooden surface using rice paste. The lines would then be cut out by the block maker. Only those portions of a page or pattern to be inked were left untouched, on the block's surface, with the remainder carved away along the grain using a fist knife known as a quan dao. Dense hardwoods such as birch, pear, or jujube were used because they withstood moisture and insects yet their regular, fine grains lent themselves to easy engraving and printing. more...

"Paper can convey a private warning, a public threat, secret temptation, open defiance..." Eric Frank Russell, Wasp (1957) In 105 when Ts'ai Lun (50-121), a courtier in the Chinese Imperial court, invented paper, little did he realize that he was opening one of the most epoch-making chapters in history. He refined and popularized the process of mixing tree fibers and wheat stalks with the bark of a mulberry tree, then pounding them together and pouring the mixture onto a woven cloth to create a lightweight writing surface. His blended, fibrous sheets were an improvement over bamboo and wood, which were awkward and heavy, and silk, which was expensive. Successive Chinese dynasties conspired to keep his invention secret, and it was not until the start of the seventh century that papermaking techniques began to appear in Japan and Korea. With the capture of Chinese paper merchants by Arab soldiers during the more...

I am not fond of visiting pictures. I go to the cinema once a month. I generally see the religious pictures with my father. Last Friday we went to the Urvashi Cinema House to see 'Luv and Kush'. There was a big crowd outside the hall. People were roaming about. Some  talking of film. Some were looking at posters. There was a great rush at the booking window. It was very difficult to get at it. The people were pushing one another. With great difficulty we got tickets. The hall was well-lighted. It was quite cool. Soon the hall was fully crowded. In front of us there was a big silver screen. Exactly at 6.30 p.m. all the lights in the hall went off. At first there were few advertisements. The film record went on playing. Then there were few news reels, and then came the cast of show. The more...

I have many friends at school and I love to play with them. In my neighborhood also there are many children who are my friends. Although I value their friendship a lot, I have another friend also who is dearest of all. That friend is my  library.  I have built a little library of my own at home. Ever since I was born my parents have been collecting books for me. It began with books to teach alphabet. Then came numbers.   Gradually I had books with short stories. My mother used to read them at bed time. Now I have tales, folk-tales from different parts of the world, fan books, books on science, history and literature. I love books. On my holidays I pick up any book and get so engrossed in it that I often forget to eat. My mother has to   yell at me to have more...

Many months ago I went to Mussoorie with my friends. All of us formed a good company. We had good time on the way. We reached there in a bus. One day, we reached the top of the highest hill. It is called Lal Tibba. We were tired. But we were pleased to see the top. We lay down on the hard surface. We gave full rest to our tired limbs. The air was quite fresh and cool. We breathed freely. The natural scenery was very charming. The beauty of nature charmed us. We looked around and below the hill. The hill was not bare. It had a very large number of trees and plants. Some plants bore flowers of different colours. The colours of flowers were quite different from the flowers in the plains. There were very tall trees of Deodar. The height of these trees terrified us. I more...

In our Constitution, the Directive Principles of State Policy "have stated that the government should provide free and compulsory education to all children up to the age of fourteen years. However because our population is so large, progress in this field has been slow. Millions of children are out of schools and they do not know how to read and write.  It is a great tragedy that such a huge number of our children does not go to school and waste their precious time as well  as their childhood wandering here and there on the road working at low wages in the factories or in the houses of wealthy people to support their family. Children cannot have a proper future without education. Education is the base which only can make their life strong and comfortable. The percentage of literacy has undoubtedly gone up since independence but it does not mean more...

"The engineer is the key figure in the material progress of the world." Sir Eric Ashby, British botanist and educator In 1860 Belgian engineer Etienne Lenoir (1822-1900) created the first gas-fired internal combustion engine, which was designed to provide an alternative to the rather cumbersome steam engines that were being used at that time. Since steam engines required furnaces, boilers, and large supplies of bulky fossil fuel to be of any use, Lenoir's idea of a more compact, workable gas engine was incredibly popular. Lenoir earned the patent for his idea in 1860 and created his first actual engine the same year. Initial demand for the invention was high and production started in France, England, and the United States. The gas engine worked by drawing a mixture of gas and uncompressed air into the cylinder during the first part of the piston's stroke, then igniting it with a jumping spark in more...

"We are concerned here with methodical digging for systematic information." Sir Mortimer Wheeler, at Mohenjo-daro Trade between people depends on a uniform set of weights and measures that can be used by both sides of the transaction to ensure that the amount obtained or handed over is correct. The first such standard weights were developed in the Indus Valley Civilization of southern Asia. This civilization was among the most advanced of its time—equal to any in the Near East or Egypt—and boasted large cities, such as Mohenjo-daro and Harappa. The system its merchants or accountants devised consisted of cubes of chert, a crystalline form of silica. These cubes were organized in series, doubling in weight from one unit to two units to four to eight and on to sixty-four units. The next block weighed 160 units, the next 320, and then proceeded in multiples of 160.The smallest units were used more...

Last week, our school organised a blood donation camp. The school hall was used for this purpose. Beds were laid out and necessary equipment were set up. Banners advertising the camp were displayed. A team of doctors and nurses from the Red Cross Organisation came to collect blood which would be used to save the lives of accident victims and seriously ill people. All the volunteers were from the school, but some parents of students also donated blood. The principal was the first donor followed by members of the staff. Then it was the turn of senior students. The younger children also wanted to donate but were not allowed to do so by the doctors who said that they were too young. Disappointed, they turned away but were asked to come back by the teacher who was in-charge of refreshments. She gave them the task of handing out sweets, bananas more...