Current Affairs Science Projects And Inventions

By the end of the 1980s, powerful lobbies within the U.S. music industry had all but killed off Digital Audiotape (DAT) as a popular recording medium and replacement for the aged and low-fidelity Philips Compact Cassette. This led the way for the Sony Corporation of Japan to develop its own proprietary digital recording format. Introduced in 1992, the MiniDisc resembles a small computer floppy disk. It is a magneto-optical, disk based data storage medium able to contain up to eighty minutes of digitized audio. The disk is placed in a suitable recorder and a laser heats one side, which makes the material susceptible to a magnetic field; a magnetic head on the other side of the disk alters the polarity of the heated area, recording the digital data—a series of ones and zeros—onto the disk. To play back the audio, the laser senses the polarization of the reflected light and interprets the digital data. After a short-lived format war with the Philips/Matsushita Digital Compact Cassette (DCC), the MiniDisc format prevailed. A factor in its success was that Sony avoided the mistakes made in the 1970s with its own Betamax video system, which failed largely because the corporation refused to allow competitors to license the technology and produce their own recorders. Although the MiniDisc became a major format in Japan, its popularity elsewhere was limited to niche markets, such as audio enthusiasts. In these territories, the Compact Cassette only died out when reasonably priced recordable CDs and MP3 players appeared on the market. MiniDisc has maintained its place as a well- established format, and, following the development in 2004 of the Hi-MD format, is also widely used as a general-purpose data storage medium. 

"Our greatest glory is not in never  falling, but in getting up every time we do" Confucius, Chinese thinker and educator The Wright brothers' historic flight of 1903 had made aeronautics a worldwide phenomenon. Air shows became increasingly popular spectacles throughout the world. A Russian artillery school graduate, Gleb Kotelnikov (1872-1944), was attending such a show in 1910 when he witnessed the death of a pilot. He was so affected by the accident that he vowed to create a safety device to help prevent such deaths. The parachute is not a particularly new idea—there are many accounts of rudimentary parachutes being used throughout the ancient world. Early prototypes of a Kotelnikov parachute contained within the pilot's helmet failed, yet Kotelnikov was unperturbed and eventually devised a parachute within a knapsack that could be worn within the confines of a plane's cockpit. Despite the dangers to their military pilots, many governments were reluctant to provide parachutes to their armed forces. However, in 1918 the German Army Air Service became the first to introduce the parachute as standard issue. Nowadays, parachutes are so reliable that they are used not just to save lives but also for recreation and entertainment. Kotelnikov was honored in 1949 for his invention by having the town in Russia where he first tested his device renamed Kotelnikovo. 

Patented in 1872, Vaseline®—the trade name for soft paraffin, petroleum jelly, and petrolatum—was invented by the British-born chemist Robert Chesebrough (1837-1933). A semi-solid mixture of hydrocarbons, Vaseline was initially derived from the rod wax that came from the drilling of petroleum. Chesebrough created it by vacuum distillation of the crude rod wax, then filtered the residue from the still through bone char. The name is thought to come from the German for water (pronounced "vasser") and the Greek for oil (elaion). The first Vaseline® factory opened in 1870 in Brooklyn, New York, and in 1911 the company built its first operation plants in Europe. Initially Chesebrough traveled around the United States selling his product by demonstrating its medicinal properties. He did this by burning his skin either with acid or with a naked flame, then rubbing the Vaseline over the wounds, and showing the healed areas of previous burns. It was primarily promoted as a treatment for grazes, burns, and cuts, but Vaseline® has no confirmed medicinal effects. Yet, it does help speed the healing process by sealing the wound from infection and moisture. In the early twentieth century, it was mixed with additives such as beeswax, to make effective mustache waxes. Now used in many skin lotions and cosmetics, Vaseline® is a popular handbag essential, with uses ranging from lip balm to blister prevention. Chesebrough lived to the age of ninety-six and claimed to have eaten a spoonful of Vaseline® a day. It is also said that when he was suffering from pleurisy he covered his body entirely in Vaseline®—and quickly recovered. 

“I readily absorb ideas from every source, frequently starting where, the last person left off."     Thomas Edison, inventor By the age of 40, inventor Thomas Edison (1847-1931) already had around 400 patents under his belt. But he was never a man to rest on his laurels. His next project, which was in fact a return to a previous project, was to try to make a success of his dictation machine. The device was an improved version of his earlier phonograph—a voice recording machine that turned speech vibrations into indents on a tin foil recording tape. In 1878, in an article in the North American Review, Edison had suggested that possible uses of his machine might include letter-writing, the teaching of spelling, and recording "the last words of dying persons." But he abandoned these ideas when the machine failed to take off. After a rival group improved on his design with their "graphophone" in the 1880s, Edison saw potential in his phonograph once more. Picking up where his competitors had left off, he worked hard to create a more practical dictation machine. Chichester Bell and Charles Tainter had already developed a method for recording using a floating stylus and a wax cylinder, so Edison simply improved on their design, marketing his "Improved Phonograph" in 1888. Initially his machine was not a success and he faced great opposition from stenographers (shorthand typists). Sales of his later "Ediphone" grew after World War I, with the help of an advertising film called "The Stenographer's Friend." 

"Beer is proof that God loves us and wants us to be happy.” Attributed to Benjamin Franklin When William Painter (1838-1906) left his home in Ireland in search of better opportunities in the United States, he could not have imagined that it would be a small, simple, and seemingly insignificant invention that would make him a very wealthy man and revolutionize the bottling industry. With hundreds upon hundreds of patents received for bottle-sealing devices, the trade press wrote that it would be difficult to come up with a novel idea. Painter took up the challenge, believing that "the only way to do a thing is to do it," and do it he did, filing a patent for the "Crown Cork" in 1891. The cap was metal with twenty-four teeth that gripped a flange around the neck of the bottle. It had a cork stopper on the inside to prevent the drink from leaking, going flat, and coming into contact with the toxic metal. The cap could be removed with a conventional corkscrew or prized open by any flat object, such as a pocket knife. Painter shrewdly mentioned in his patent application and marketing material that an opening device would be the most efficient method, and accordingly, in 1894, he received a patent for the tool he had designed. To convince brewers and bottlers to change to his system, which required new bottles and machinery, Painter shipped some beer sealed with the Crown Cork from North America to South America. The results spoke for themselves. By 1906 the Crown Cork and Seal Company was opening factories around the world, and by the 1930s it was supplying almost half of the world's bottle caps. 

"Knowledge belongs to humanity, and is the torch which illuminates the world" Louis Pasteur, scientist Before the invention of the torch or flashlight, it was impossible for children to experience the guilty pleasure of staying up late at night reading a book under the covers. It began life as the idea of Joshua Lionel Cowen, who wanted to make flowerpots light up as a decorative gimmick. He sold his company (and his idea) to Conrad Hubert (1856-1928), a manufacturer of Christmas lights and other electric novelties. Hubert decided to reinvent Cowen's light without the flowerpot. One of his shop workers, British inventor David Misell came up with a basic tube made from paper and other fibers, complete with a bulb and reflector in 1898. In an astute marketing move, New York's policemen were given the flashlights to try out, and soon everyone wanted one. Hubert's company became Eveready and its catalog pictured the new flashlight alongside the words "Let there be light." Despite weak early batteries and inefficient carbon filament bulbs, the new flashlights were popular. In 1910 tungsten filament bulbs vastly improved the brightness and power usage of flashlights, and this technology dominated the market for more than fifty years. Fluorescent bulbs were introduced in 1968, followed by halogen bulbs in 1984. Today the best bulbs are highly efficient white LEDs, which can shine for up to thirty-five hours on one set of batteries. 

"When we exhale, a large portion of the oxygen we inhaled, around 80 percent, is exhaled..." Adam Altman, Long Island Divers Association Scuba diving usually involves filling a tank with air, strapping it to your back, and breathing from it underwater. This simple system is called open circuit scuba (or self-contained underwater-breathing apparatus). Before this method of scuba diving caught on, however, people were using rebreathers. In 1878, Henry Fleuss built a diving system that allowed the user to breathe the same air over and over again. Using a rubber mask, a breathing bag, a copper tank, and a bit of string, he constructed the first scuba rebreather. A rebreather works by removing carbon dioxide from the diver's exhaled gas and recycling its usable components. The contraption uses an expandable breathing bag to hold the exhaled gas and a system of valves to keep the gas flowing in only one direction. A carbon dioxide scrubber then filters the exhaled gas into a breathable form. In the carbon dioxide scrubber, the exhaled air moves past an absorbent mixture often containing soda lime. The carbon dioxide reacts with the soda lime, and the other components of air pass through to be inhaled again. Air lasts longer with a rebreather, so users can use smaller tanks. The rebreather is more efficient than normal scuba systems, whose users lose 75 percent of the available oxygen when exhaling. Rebreathers also produce dramatically fewer bubbles than their counterparts, thus helping naval divers to remain inconspicuous. Similar systems are used in space suits and by firefighters. Rebreathers are also now affordable enough for recreational divers to experiment without paying exorbitant costs. 

"My father hated radio; he couldn't wait for television to be invented so he could hate that too." Peter De Vries, writer Selenium has a lower electrical resistance when it is soaked in bright light than it does when it is in darkness. This means that by altering the light shone onto a selenium cell, the amount of electricity that can pass through it can be changed. This, combined with the knowledge that all we see is made up of different shades of light and dark, allowed German engineer Paul Nipkow (1860-1940) to come up with a way to convert pictures into electrical signals. Nipkow's system worked by using a rotating disk that has a spiraled series of holes punched in it. When the disk turns, the moving holes break up the image into a series of varying light signals. When light passes through the holes onto the selenium cells, the selenium reacts. The electrical signal created by passing a current through these selenium cells can then travel by wire to power a lamp set up elsewhere. If a second disk rotating in sync with the first is placed in front of this lamp, the light signals will match up with the holes in the second disk, creating a replication of the original image. If this is done at high speed, the eye will no longer be able to recognize that the light signals are being emitted in quick succession and will instead see one whole image. This process of breaking up an image into small dots, or pixels, is the basic principle on which television is based. 

"The truth is, a halftone is nothing more than a kind of magic trick" Bill Stephens, printer The popularity of photography soared during the 1800s and with that grew a desire to print photographs in books and newspapers. However, the printing press was not capable of producing the continuous tone images, with infinite shades of gray, of photographs. It was not until 1881 that American Frederic Ives (1856-1937) developed the first successful halftone process. Halftone printing involves converting continuous tone images to images made of dots of various sizes. The key to this system is that it exploits the limitations of the human eye. With the right resolution, the individual dots cannot be seen, resulting in the illusion of shades of gray, with larger dots appearing as darker shades. The first step is to produce a negative using a process camera. The process camera has a screen between the lens and the film that contains a grid. The grid divides the image into small squares through which light passes, resulting in discrete spots. The different size spots are made as a result of different amounts of light landing on the film; more light results in bigger spots. The negative is then used to produce an engraving, often by acid etching of a metal plate, with image areas left standing proud of the surface. The resulting plates are then coated with ink and the image printed. This cheap and effective halftone process is still used today, mostly in newspapers. 

"The Iron Age itself came very early to Africa, probably around the sixth century B.C.E...." Richard Hooker, historian Steel was first produced in carbon furnaces in sub- Saharan East Africa, around 1500 B.C.E. Steel is an alloy of iron and 0.2-2.4 percent carbon. It can also contain trace elements such as vanadium, manganese, or tungsten. The carbon acts as a hardening agent and prevents the lattices of iron crystals from sliding past each other. The more carbon present in steel, the harder it is, but this is at the expense of increased brittleness. By controlling the exact ratio of iron to carbon and other elements, the properties of the steel can be tuned to those needed for a specific function. Damascan steel (also known as Wootz steel) was famed for its strength and ability to keep an edge. It actually originated from India around 300 b.c.e. before being widely exported; it was identified by its banded appearance. Recent studies .of blades made with Wootz steel have found that they contain carbon nanotubes that contributed to their legendary properties. Unfortunately, the process for making the steel died out in the eighteenth century after the necessary ores were depleted. Modern steel making took off in Europe in the late 1850s with the invention of the Bessemer process. The key element of this process was the removal of impurities via oxidation, achieved by blowing air through the molten iron. For the first time this allowed cheap production of steel on an industrial scale.