Uttarakhand State Exams

“Vases and shards ...the true alphabet of archeologists in every country" Sir William Flinders Petrie, archeologist As applies to all early inventions, we do not know the name of the man or woman who invented pottery. No first potter carved his or her name or initials in the base of a pot to claim first prize. However, it has long been assumed that whoever the creative person was, he or she would have lived somewhere in the Near East of Asia. It was therefore something of an archeological shock when, in the 1960s, pots dating to around 10,000 B.C.E. were discovered on the Far Eastern side of Asia, thousands of miles away at Nasunahara on the island of Kyusu in Japan. These pots, found in caves, were made by nomadic hunter-gatherers, rather than settled farmers or urban dwellers. Just as important, the pots were made by firing or heating the more...

"[The artificial skin] is soft and pliable, unlike other substances used to cover burned-off skin." John F. Burke Human skin is a marvel of engineering. It is tough yet stretchy and pliable, and acts as an impermeable barrier against water loss, infection, and cell damage from the sun's ultraviolet (UV) rays. With this range of properties, it is a very difficult material to duplicate. John F. Burke, a surgeon at Massachusetts General Hospital in the United States, was looking for a reliable skin replacement for the treatment of burn victims. Skin is usually grafted from other parts of the patient's body, but in cases where the burns cover 50 percent or more of the body, often there is not enough healthy skin to cover the damaged area. In the 1970s Burke teamed up with loannis V. Yannas, a chemistry professor at Massachusetts Institute of Technology (MIT), who was studying a more...

Ever since the invention by Alhazen (965-1040) of the pinhole camera, which projected an image onto a surface, people sought a way of "fixing," and thus recording, that image. By accident, in 1727, the German chemist Johann Schuize discovered that a mixture of chalk, nitric acid, and silver darkened when exposed to sunlight, and the rate of darkening increased if more silver was added. By 1777 the Swedish chemist Carl Scheele had been able to fix, or make permanent, the results of this change using ammonia. Joseph Nicephore Niepce (1765-1833) produced the first permanent photographic image in 1826. He first used a flat pewter plate covered with bitumen, but then quickly moved on to silver compounds. Louis Daguerre produced silvered images that were very delicate and could not be copied. Although the exposure time was about ten minutes, he managed to produce daguerreotypes of famous people such as Abraham Lincoln more...

"Steam is no stronger now than it was a hundred years ago but it is put to better use." Ralph Waldo Emerson, writer In the late eighteenth century, there were many wagonways and tramways in Europe. These had iron rails and horsedrawn wagons fitted with flanged wheels. The first steam locomotive to run on rails was built by Richard Trevithick (1771-1833) of Cornwall, England. Trevithick was encouraged to develop an engine that was more efficient and cheaper to run than the low-pressure Watt and Newcomen type; he was the first to harness high-pressure steam. Trevithick's Puffing Devil (1801) and London Steam Carriage (1803) were demonstration steam vehicles, but on February 21, 1804, his Penydarren locomotive pulled five wagons, seventy passengers, and 10 tons of iron down an iron railway between Merthyr Tydfil and Abercynnon in south Wales. This reasonably reliable and robust machine proved that heavy trucks could be hauled more...

"For NASA, space is still a high priority. ...If we don't succeed we run the risk of failure." Dan Quayle, U.S. vice-president (1989-1993) X-rays are absorbed by Earth's atmosphere so one has to climb above the atmosphere to see them. NASA's Uhuru (1970) and the United Kingdom's Ariel V (1974) were spin-stabilized satellites that discovered around 400 bright X-ray sources. Astronomers realized that X-rays provide vital clues to the death-throws of stars, specifically supernova explosions and the final transitions to white dwarf, neutron star, and black hole states. X-rays are a vital-component of the radiation coming from energetic events such as solar flares. Two technical advances helped the development of space telescopes. One was the construction of advanced confocal mirror systems and the other was the development of two-dimensional X-ray imaging gas scintillation proportional counters. Using these, the United States launched the first orbiting satellite containing a fully imaging X-ray more...

Today mobile video-recording technology must fit into the palm of the hand, or be integrated into the back of a mobile phone, before anyone would consider paying any money for it. But before the camcorder was invented, anyone wanting to capture moving footage on film had to use an incredibly unwieldy two-part machine. Worse still, the camera itself was all that one person could reasonably carry, so a partner had to be persuaded to carry the video cassette recorder (VCR) alongside. The older equipment also had no playback screen, so whenever it was necessary to watch recently recorded material, a television screen had to be available nearby in which to plug the VCR, The cumbersome equipment was troublesome, particularly for broadcast journalists, movie makers, students, and others working in the field. However, advances in technology and design meant that soon various pioneers of video-recording equipment were shrinking down the basic more...

"What is laid down, ordered ...is never enough... life always spills over the rim of every cup." Boris Pasternak, writer Englishwoman Mandy Haberman was not particularly involved with the business of invention or innovation until the birth of her third child, Emily, in 1980. Emily was born with Stickler syndrome, a genetic disorder that impaired her sucking ability and made feeding difficult. Finding no helpful products available, Haberman applied her talent for problem solving and began to think about a feeder to meet the needs of Emily and other children with sucking difficulties. Ten years later, in 1990 at a friend's house, she was struck by inspiration once again when a toddler spilled blackcurrant juice from a training cup over their cream-colored carpet. Training cups at that time could be closed manually, but Haberman developed a better cup with a unique valve in the mouthpiece that only let out liquid more...

In modern culture, the lightbulb is the symbol we often use to denote a sudden flash of inspiration. It is ironic, then, that the lightbulb itself is not the result of just one exceptional idea, but followed the contributions of many men over several decades. Thomas Edison is often credited with the design for the first practical lightbulb, but he was not responsible for the early developments. Without the input of American chemist Irving Langmuir (1881-1957), the lightbulb as we know it today might not have existed. In the late nineteenth century, Edison filed numerous patents for improvements to electric lighting. His 1880 patent application for an electric lamp certainly depicts what we would immediately recognize as a lightbulb. But it was Langmuir's improvements to the filament at its core that gave us the lightbulb's modern design. Langmuir was a researcher at Edison's General Electric Company, where he was studying more...

The oldest known blast furnaces were built during the Han Dynasty of China in the fourth century B.C.E. Early blast furnace production of cast iron evolved from furnaces used to melt bronze. Iron was essential to military success by the time the State of Qin had unified China (221 B.C.E.). By the eleventh century C.E., the Song Dynasty Chinese iron industry switched from using charcoal to coal for casting iron and steel, saving thousands of acres of woodland. In a blast furnace, fuel and ore are supplied through the top of the furnace, while air is blown into the bottom of the chamber. The chemical reaction takes place as the material moves downward, producing molten metal and slag at the bottom, with flue gases exiting from the top of the furnace. The oldest known blast furnaces in the West were built in Durstel in Switzerland,the Markische Sauerland in Germany, and more...

"In 1854...ltookout a patent for puddling iron by means of steam." James Nasmyth In the early days of the Industrial Revolution, large pieces of metal were made by forging multiple small segments then welding them together into a finished product. Metalworking hammers of the day were capable of forging small items efficiently, but when a large item was placed in them, they had little room to maneuver and therefore little force. This fact became painfully obvious when the Great Western Steamship Company began to build the SS Great Britain. The engineer in charge found it impossible to locate a hammer capable of producing the mammoth paddle wheels that were to propel the ship. Edinburgh-born engineer James Nasmyth (1808-1890) heard about the problem and sketched out a design for a large steam-powered hammer that. would be capable of producing just such a piece of equipment. Nasmyth's hammer consisted of a piston more...