Archives March 2013

"When you see the little green pictures on CNN of people ...at night, think of Professor Spicer." Piero Pianetta In early World War II, U.S. engineer William Spicer (1929-2004) was aware of the visibility problem of conducting military operations at night and was looking into a solution based on photoemission. In photoemission, light is treated as packages of energy called photons, which strike a material to bounce out electrons. In 1942 Spicer developed the first night vision goggles using image enhancement. At night, light is present in small quantities from various sources, but our eyes may not detect it. The photons from this light enter the goggle lens and strike a light-sensitive surface called a photocathode, releasing electrons. The electrons are accelerated toward a microchannel plate that releases thousands more electrons through a cascade reaction. These electrons hit a screen coated with phosphor chemicals to emit visible light. As thousands more...

The 1968 Kail Joint Computer Conference at San Francisco in the United States presented a remarkable number of "firsts." Among them was the first video teleconference; the first use of hypertext (the foundation of today's web links); and the first presentation, by the Stanford Research Institute (SRI), of NLS, short for oNLine System, the revolutionary ancestor of modern computer server software. Such dazzling displays likely distracted people from another important first, moved by the hand of SRI researcher Douglas Engelbart (b. 1925): the computer mouse. Far from the sleek ergonomic devices of today, the first computer mouse was a wooden box with wheels and a thick electric cord. Engelbart and colleague Bill English (b. 1929) first came up with the idea in 1963, and created the device as a very small piece of a much larger computer project. They were looking for something that allowed computer users to easily interact more...

Descriptions of Dr. Igor Gamow (b. 1936) depict him as a cross between Indiana Jones and Albert Einstein, a bold adventuring spirit driven by an enquiring scientific mind. Gamow's father was the physicist and cosmologist George Gamow, and his mother was a famous ballet dancer. The young Gamow held down jobs as diverse as horse-breaker and karate instructor before he finally succumbed to the lure of science and enrolled at the University of Colorado. He eventually gained a PhD in Microbiology and Biophysics and went on to lecture in these subjects, although his passion for adventure and the outdoors did not wane. It was while Gamow was investigating training at altitude that the idea for his sleeping bag came about. He envisaged a bubble that athletes living at high altitude could use to get the most out of their training. Altitude sickness occurs when a person ascends to a height more...

"Horseshoing, very likely, was invented by different nations about the same period...." Scientific American (1891) Horses have played central roles in the histories of various powerful empires, and their employment was boosted by the invention of the horseshoe. Protecting horses' hooves from wear and tear on hard or rough surfaces allowed for longer journeys when the horse was the common mode of transport and a domestic working animal. It also made them more effective when used in the cavalry as part of a military campaign. The precise date of its invention is unknown, but the Roman poet Catullus mentions a mule losing its shoe in the first century B.C.E. Evidence from Roman regions to the north of the Alps suggests that horses from what is now Germany may have been the first to use horseshoes regularly, from around 100 C.E. Over the years horseshoe design has improved from the "hipposandal" more...

"A computer who must make many difficult calculations usually has a slide rule close at hand." Pickett manual The slide rule is a mechanical device used to carry out complicated mathematical functions. It is based on two logarithmic scales that move parallel to each other and are aligned according to the desired calculation. To multiply two numbers, for example, the logs are added and raised to the power ten; to divide, the logs are subtracted. In 1620 Edmund Gunter (1581-1626), an English clergyman and Gresham College Professor of Astronomy, produced a logarithmic scale and used dividers to take off specific distances to do the calculations. William   Oughtred   (1574-1660), mathematician and rector of Albury, did away with the dividers by using two sliding Gunter rules side by side in circa 1622 and described his circular slide rule in Circles of Proportion and the Horizontal Instrument (1632). Sliding different distances more...

Introduction. Today, we have a lot of competitions in our daily life. Examination is one of them. It has become a part and parcel of our life. Intelligent and labourious students always welcome and take the examinations as challenges. Their performance get excellent result for them. But, for the dull and lazy students, the very name of examination is mind boggling. They become confused and forget all what they have learnt so far at the time of exam. They behave like idiots. They become perspired and non-pulsed. Types of Examinations. The Directorate of Education is planning to make the examination process in our school 'Student friendly'. As per this new scheme, students appear in four CCEP exams. Continuous Comprehensive Evaluation Programme) in a single session. In these exams., students have multiple choice type questions which are very beneficial for their future competitive career. Then, there are terminals and annual examinations. more...

We are living in an electronic age. The whole world is taking a new turn with every fraction of time. It has given birth to globalization. The world has been contracted and concise at a tip. There are a lot of new means of communication which have made our life so simple and easy going. Mobile phone can be seen as the most used present day phenomenon in this fast growing time. Mobile phone is a revolutionary step in the field of tele-communication. We had the days when the telephones only served the purpose of communication through sound. Mobile phone has completely changed the concept of the telephoning. Now a phone is not only a mere phone but it is a lot in itself. A mobile phone works on a unique networked system which needs no wiring, no fixation and no botheration. H   Originally it was used in cars, more...

Whenever we suffer from an ailment, we go to the doctor's place for his advice and medicines. A true doctor helps the sick with his knowledge and medicines. As such, a doctor is an important member of the society. Last Tuesday it started to rain when I was coming back from school. I was completely drenched. The cold wind made me shiver with cold. I sneezed badly when I stepped in the house. I had fever. So, my mother changed my clothes and took me to a doctor’s clinic. The clinic was not far from my house. I sat on a chair while my mother got my name registered with  the receptionist. Then we waited for our turn. There were two rows of chairs along the wall. Five persons were seated on the chairs. One of them was a mother with a tiny baby in her hands. It cried loudly more...

The long colonial rule left India a poor and under developed Country. As a result we have been facing several serious problems since independence. Poverty is one of them. Poverty means not possessing the ability to acquire the minimum basic need for a decent human existence like food, clothing, shelter, education and health care. Those who are unable to fulfill these needs are below the poverty line. Though his acute problem is being faced by several parts of the world but India still has the world's largest number of poor people in a single country. Out of 1 billion inhabitants, an estimated 350-400 million are unluckily below the poverty line. The problem of poverty is wide spread in our country. It affects the development of the country by forming a vicious circle. A large number of people do not get proper nourishment Therefore they become physically weak and are unable more...

"The most important of my discoveries have been suggested to me by my failures." Sir Humphrey Davy The name of Sir Humphry Davy (1778-1829) will forever be associated with the famous safety lamp that he developed for miners, but his demonstration of the arc lamp in many ways was more significant. Considered one of the greatest British scientists, Davy became renowned for his mesmerizing public lectures, including his demonstration of the effects of laughing gas. In 1801 the twenty-two-year-old Davy was appointed as the director of the laboratory at the new Royal Institution in London, where he began his work in electrochemistry. It was here that he first discovered the principles behind what would eventually become the arc lamp. He used two sticks of carbon in the form of charcoal and connected each of them by wire to opposite terminals of a battery. When he held the two carbon "electrodes" more...