Archives August 2013

Hunting is of many types. Someone hunts with the eyes, the fair sex. Sportsman hits the ball with foot, stick or a bat. Soldiers hunt the life of the enemy's army. Pickpocks hunt for the pockets of others. Underworld mafias hunt for the life of their counterparts Dacoits and thieves hunt for the money which some rich people have. A person who is fond of drinking hunts for a bottle of whisky to quench his thirst. So every member of the society is hunting for one thing or the other. To overcome the problems of the food man started hunting animals. After sometimes hunting was looked upon as a spor) though for royal and noble families. He hunted all types of animals as adventurous deed. But man soon got bored of hunting as it became a one sided affair in the age of modern equipments and latest modernized rifles which more...

More than a million years ago, members of the species Homo erectus were making stone tools designed for chopping that can be described as early hand axes. They were teardrop-shaped and roughly made, flaked on either side to form a sharp cutting edge. However, not until the rise of farming during the late Stone Age did such tools come to resemble what we would now recognize as the axe. There was widespread trade in these tools around this time and stone axes have been uncovered at many Neolithic meeting places. Axes clearly designed to be mounted (hatted) on handles have been found at a site near Mount Hagen in New Guinea. By analyzing samples of pollen from around the same era—thought be around 8,000 years ago—archeologists have concluded that they were probably employed in the opening up of the rain forest, during agricultural development, to allow light to reach crops. more...

Many people have sacrificed their lives to quench the thirst for knowledge and to satisfy his curiosity to gain knowledge. In the Olden days people used to worship sun and moon thinking them sacred heavenly bodies. But the scientific investigation had proved that sun is an ordinary star and moon is a planet like other planets. After this the man has entered the age of the space travel. The invention of-rocket was the first step in space travel. Scientists had already discovered that there was neither air nor water on the moon. The moon was the first target of the man. The moon is our nearest neighbor. It is about 300000 kms from the earth. A space ship travelling at a speed of 4000 kms/hour can cover this distance in 10 hours. The scientists had further discovered that the surface of moon is rough and full of craters, rocks and more...

The origins of the spinning wheel remain unsure, but the machine is thought to have been invented around 700 in India, where it was used to turn fibers into thread or yarn that were then woven into cloth. Earlier hand-spinning methods were superseded by mounting the spindle horizontally and rotating it by slowly turning a large wheel with the right hand. The fiber was held at an angle in the operator's left hand to produce the necessary twist. The spinning wheel reached Europe in the Middle Ages, becoming part of a cottage industry that used simple hand-operated tools. It persisted in this context until the eighteenth century. In Britain the new cotton industry was modeled on the old woolen cloth industry. The most complicated apparatus was the loom, worked by a single weaver and normally kept in an upstairs room where a window provided natural light. The weavers were usually more...

"What is life? It is a flash of a firefly in the night. It is the breath of a buffalo in the wintertime…” Crowfoot, chief of the Blackfoot First Nation Native Americans on the Great Plains led nomadic lives. They used buffalo for almost everything, eating their meat and making clothes and tent coverings from their skins. Living on herds of animals that were always on the move, they were constantly on the move too, which meant living in tents and owning only what could be carried to the next camp. Ideally, however, people like to carry more than can fit into one bag. On roadways and hard ground, carts are the best solution, and in the far north snow and ice lie on the ground and dragging a sled is easy because the ground is slippery. Traveling across soft soil, however, neither of these options work. The response of more...

"Well we've got a new device here. It's not a transistor, it's something different." William Boyle, coinventor Charge-coupled device (CCD) technology is the bedrock of digital cameras and video but it started out as a new form of memory. One day in 1969 William Boyle (b. 1924) and George Smith (b. 1930) were brainstorming at Bell Labs in New Jersey and decided to play around with merging two of the new technologies that were being worked on— semiconductor bubble memory and the video phone. The pair worked on a new principle of handling small pockets of electrical charge on a silicon chip that was similar to the work being done on moving microscopic "bubbles" of magnetism around on various materials. They called their invention the charge-coupled device. It soon became clear that the small packets of charge on the CCD could be put there using the photoelectric effect, which meant more...

"The mechanism falls like thunder; the head flies off, blood spurts, the man is no more." Joseph-lgnace Guillotin, 1789 In 1789, at the start of the French Revolution, Joseph- Ignace Guillotin (1738-1814), a medical doctor of progressive views, proposed a thorough-going reform of the French penal system. Inspired by the humane and rational principles of the Enlightenment, Guillotin's proposals included a single method of execution to replace the messy horrors of breaking on the wheel and hanging by the neck. Guillotin's mechanism would prevent suffering, while making capital punishment more democratic; beheading was traditionally the punishment reserved for aristocrats— an efficient decapitation machine would spread that privilege to all classes. In 1791 the French National Assembly appointed a committee to push the project through. Although Guillotin was involved, the prime mover was Dr. Antoine Louis, Royal Physician and Secretary of the Academy of Surgery. The basic design adopted, with a more...

"[Developing an escape slide] is like trying to balance a sheet of plywood on the head of a pin." Mark Robertson, engineer If an airplane crashes, an exit strategy needs to be in place. In fact, aviation authority rules state that it must be possible to completely evacuate an airplane within ninety seconds, under conditions of pitch black darkness and with half the exits blocked. In 1965 Jack Grant, who was working at Quantas Airlines as a safety superintendent, invented a superior inflatable escape slide that could double up as a life raft in the event of a crash landing at sea. His design was tried and tested in Sydney, Australia, with great success. In the 1960s, aviation authorities suggested that inflatable slides would only be useful if they could be fully deployed within twenty-five seconds, in moderate weather. The slide met these requirements and was also light and compact; more...

"To err is human, but to really foul things up requires a computer." Farmers' Almanac An accomplished mathematician and mechanical engineer, Charles Babbage (1791-1871) combined these two disciplines to create a "difference engine" capable of solving polynomial functions without having to use unreliable, hand-calculated tables. Despite generous government funding, Babbage sadly never fully finished his difference engine and the project was abandoned in 1834. This did not stop Babbage from thinking about computing, however. In 1835 he released designs for his "analytical engine," a device similar to the difference engine but which, by using programmable punched cards, had many more potential functions than just calculating polynomials. The analytical engine was never built, although Babbage produced thousands of detailed diagrams. Using the lessons learned from the analytical engine, Babbage created a more efficient and smaller difference engine in 1849. Difference Engine No. 2 was not built until 1991, when the London more...

"The Sl is not static but evolves to match the world's increasingly demanding requirements." International Bureau of Weights and Measures Scientists and engineers constantly need to measure distances, masses, times, temperatures, densities, velocities, electrical currents, and so on. All these quantities are then expressed as a number, and this means that units are absolutely vital. The idea of implementing common bases for all the units began with the British Association for the Advancement of Science in 1874. They suggested the centimeter for length, the gram for weight, and the second for time, which was known as the C.G.S. sytem. Prefixes such as mega- and micro- could then be used to indicate decimal multiples and submultiples. Unfortunately, this C.G.S. system was rather inconvenient in the field of magnetism and electricity. In 1889 the Conference Generaledes Poidset Mesures decided that the meter, kilogram, and second (m.k.s.) might be more appropriate. In 1946 more...