Archives June 2013

A simple compass indicates the direction of a magnetic field, but the magnetometer, invented by the German mathematician and scientist C. F. Gauss (1777-1855), could also measure its absolute strength. Before Gauss's time, people had compared the fields at two different spots on Earth by observing how long it took a suspended magnetized needle to make a certain number of oscillations. Gauss, and his physics professor friend Wilhelm Weber (1804-1891), gauged the field strength of the magnetized needle by measuring by how much it twisted two fibers from which it was suspended, when held at a right angle to Earth's field. Gauss and Weber founded the Magnetischer Verein (Magnetic Club), whose members measured not only magnetic fields all over Earth but also their variations with time, caused by slow changes in Earth's liquid iron core and by changes in the electron clouds that surround Earth. Electron clouds are influenced by more...

"The Stirling engine is fuel independent, it doesn't even need any fuel- the sun is enough!" Lund Institute of Technology,Sweden Scottish clergyman Reverend Robert Stirling (1790- 1878) began work on a new type of engine in the hope of replacing steam engines in the workplace. At the time steam engines were unstable, dangerous, and prone to explode, frequently causing horrific accidents. Spurred on by the number of people attending his parish who were in danger, he developed what would subsequently be called the Stirling or hot-air engine. The Stirling engine needs an external heat source that can be almost anything—solar, chemical, or nuclear energy. The engine is then powered by the heating and cooling of a gas contained in a cylinder. As the Stirling engine does not rely on explosions it is quiet in operation and at the time was much safer than the steam engine. Stirling's design added an more...

In 1901 Frank Hornby (1863-1936), of Liverpool, England, together with his business partner David Elliott. produced a model construction kit for children consisting of a collection of reusable perforated strips, plates, and angle girders that could be fastened with brass nuts and bolts. Called Mechanics Made Easy, the name was changed to Meccano® when Hornby took over the whole business in 1908. The toy appeared in a range of different sets, each enabling larger and more complicated models to be produced, culminating in the ultimate—set number 10.The accompanying instructions showed how items including a double-decker bus, a beam bridge, a cargo ship, a locomotive, and the Eiffel Tower could be constructed. Wheels, gears, axles, and motors (both steam and clockwork) were also provided. The great joy of Meccano® was its versatility and the fact that it could be reused again—breaking up the model just made and rebuilding an entirely different more...

A lion is a majestic animal due to its royal appearance and walking. It is found in the forests of Gujarat in India and in some African countries. The African lion is bigger than the Indian one. A lion holds its head proudly when it walks. It is called the king of all beasts due to its majestic style, gait and might. It can fight and kill even stronger and larger animals than itself. A lion is a little shorter in length than a tiger, but is as high as a tiger. It has four legs, two bright eyes, two ears and a tail. Its teeth are very sharp and the claws in the paws are very powerful. The black mane around a male lion makes it look like a royal and regal animal. It feeds on the flesh of wild animals like wild buffalo, giraffe and deer. It is more...

Holography, coming from the Greek words holos (whole) and grafe (writing), is a form of photography that allows an image to be recorded in 3D. Discovered in 1948 by Hungarian born Dennis Gabor (1900-1979) while working for the Thomson-Houston company in Rugby, England, its early development was hampered by insufficient light sources. Gabor's holography stored 3D images by encoding them within a beam of light, but the mercury arc lamp he used produced variable results. The invention of the laser by a team of Russian and U.S. scientists in 1960 provided a pure, intense light that was ideal for creating holograms. The pulsed-ruby laser emits a very powerful burst of light that lasts a few nanoseconds and effectively freezes movement. The development of the laser enabled the first experiments in optically storing and retrieving images. The first laser-transmission hologram of 3D objects, a toy train and a bird, occurred in more...

Our country got Independence from British Empire on 15th August, 1947. From that time Independence Day is celebrated with great enthusiasm in every part of the country. This is a red letter day in the history of India. Delhi being the capital city special function is held here. The main function is held at Red Fort. Prime Minister of the country unfurls the National Flag from the ramparts of the Red Fort. The whole place in front of Red Fort and adjoining park looks neat and clean. Loudspeakers are installed at various places. Police arrangement is made to control public. A tight security arrangement by military personnel is also made. A good seating arrangement for sitting of VIP's is also made. On reaching of the Prime Minister on the Red Fort the whole place resounds with the slogan "Bharat Mata Ki Jai".  Then the Prime Minister unfurls the National Flag. more...

Most useful technologies take time to mature; usually there are at least a couple of years between an idea's conception and a final working model. When it comes to inkjet printing, however, it took much longer—the patent for directing ink onto paper using electrostatic forces was granted to Lord Kelvin in 1867. Before the 1980s, printing from a computer was a slow, unrewarding task. The mechanisms behind those early printers used moving parts, pumps, and bladders that made them expensive, clumsy, and inefficient. The modern Inkjet was to change all this by using heat or electrostatic forces to produce uniform droplets and precision results. In Japan in the 1970s, Canon and Hewlett-Packard were competing with each other to produce the first reliable inkjet printer. Hewlett-Packard was beaten by a Canon researcher named Ichiro Endo who invented the first thermal inkjet printer in 1977. He was inspired when he saw a more...

June 12, 2013 will mark the commencement of online submission process for the preparation of a provisional merit list for the state quota admissions to medical, dental and other health science courses through NEET UG in Maharashtra. For the same, aspirants strictly need to adhere to some set of rules and guidelines:

• Only those candidates who enroll themselves online will be eligible for admission.
• Candidates have to access the website: www.dmer.org to submit their information before 10pm on June 20.
• Those who fail to submit the information within time will not figure in the state merit more...

"Rest your mill-turning hand... the nymphs [now carry out] the chores your hands performed." Antipater of Thessalonica, epigrammatist The earliest reference to watermills is found in the writings of Antipater of Thessalonica, describing their use for the grinding of grain in the first century B.C.E. These ancient Greek devices consisted of a millstone mounted on a vertical axis and rotated against a stationary stone bed by a horizontal paddle wheel spinning in a fast-flowing stream. This type of watermill has also been discovered throughout Ireland, Scandinavia, and China. The Romans were the first to devise a more efficient and versatile machine with a horizontal axis, which may have been inspired by ancient Eastern waterwheels, originally used for lifting water. The medieval Islamic nations embraced the watermill from the seventh century, building mills in bridges and on the sides of moored ships, or channeling water from dams to supply them. They more...

The first binoculars were really "opera glasses," and these small instruments consisted of two small Galilean telescopes side by side. The combination of a convex objective lens and a concave eyepiece produced a rather limited field of view and a magnification of about three. By the 1790s the Venetian optician Lorenzo Selva had introduced a central adjustable hinge, enabling the binocular eyepieces to be moved apart or close together. The center-wheel focusing mechanism was introduced about 1830. A Keplerian telescope system of two convex lenses was used for astronomical observations but this had a huge disadvantage for terrestrial use as the image was inverted. An Italian artillery officer, Paolo Ignazio Pietro Porro (1801-1875), overcame the problem of inversion by placing two prisms in a Z-shaped configuration between each objective lens and eyepiece. This widened the binoculars and separated the objective lenses. It also improved the user's stereoscopic vision and gave more...