Current Affairs Science Projects And Inventions

"Tape recording in your basement or bedroom used to be a freak thing. Now anybody can do it." Les Paul, musician At the end of the nineteenth century, Valdemar Poulsen developed the telegraphone as a means of recording sound on a magnetized wire. However, the sound quality of these machines was poor, and the wire itself was usually built into the machine, making it of little use for long-term audio storage. A breakthrough came in 1928 when German engineer Dr. Fritz Pfleumer (1881-1945) successfully fixed magnetic powder to a thin strip of paper. This was then able to record magnetic signals more effectively than magnetic wire. In 1930, the AEG company of Berlin began work on the magnetophone, an audio recorder that would make use of the Pfleumer principle. To develop the tape itself, it collaborated with another illustrious name in German electronics, BASF, which used its expertise in plastics to create a new type of recording medium. The system BASF developed used a narrow band of cellulose acetate coated with a lacquer of iron oxide, thus enabling the tape to be magnetized in the recording process. The AEG K1 magnetophone and the BASF magnetic tape were exhibited together at the 1935 Berlin Radio Fair. The AEG K1 was used extensively by the Nazis during World War II. After the war, a number of models were shipped to the United States, where they formed the basis of a revolution in audio recording. 

In 1902 American president Theodore Roosevelt went on a bear hunting expedition in Mississippi that led to the invention of perhaps the most iconic children's toy in history. Holt Collier, a former slave and prodigious huntsman, was charged with organizing the chase. In order to provide Roosevelt with a clear shot, Collier and his hounds tracked down a bear and drove it to the stand where the president was waiting. However, when Collier arrived with the bear, Roosevelt had left for lunch. In the ensuing confusion the bear attacked one of the hunting dogs. But unwilling to kill the beast he'd promised to the president, Collier simply knocked it out with his rifle and tied it to a tree. When Roosevelt returned a short while later he was impressed by Collier's feat, but refused to kill the defenseless bear. The episode gained widespread media attention, and in November 1902 the Washington Post ran a series of Clifford Berryman cartoons, initially featuring Roosevelt and an adult bear tied to a tree. In subsequent cartoons the bear was depicted as an endearing little cub, and inspired by the drawings, Morris and Rose Michtom—two shopkeepers from Brooklyn, New York—created a toy bear. Named after "Teddy" Roosevelt, theirs was not a real-life representation, and its sweet and innocent looks became a huge hit with society ladies and children. The Michtoms subsequently founded the Ideal Novelty and Toy Company, which still exists today. Coinddentally, German seamstress Margarete Steiff also began producing toy bears at around the same time. Initially shunned in Europe, they flew off the shelves in the United States. Steiff bears—with their trademark button in the left ear—were always the most . expensive ones, and hence their antique models still command the highest prices among collectors. 

"Engineering is the... art of applying science to the optimum conversion of natural resources." Professor Ralph J. Smith, Stanford University Die-casting is the name given to a process of producing identical and often complicated metal parts by forcing molten metal under high pressure into a reusable type of mold, which is known as a die. It is a four-step process. First the inside of the die is coated with a lubricant—used partly to help control the temperature of the mold, and partly to aid the removal of the cast when complete. Molten metal is then injected into the die under high pressure. Generally non ferrous metals are used in die-casting. Zinc is popular as it is easy to cast and has a low melting point, which increases the working lifespan of the die. Aluminum is also used as it is very lightweight. The metal is kept under pressure until the casting has solidified. The die is then opened, the molding scrap is removed (which will then be remelted and recycled), and the piece is generally complete, although various finishes may be applied. German-born mechanic Herman Doehler 0872-1964), founder of the Doehler Die Casting Company, created the first die-casting machine in 1905; he was issued a patent for this process in 1906 and set up his company in Brooklyn in 1907, moving to Batavia, New York, in 1921. Among other achievements in the field of die-casting, he went on to become the largest producer of hood ornaments for American cars. 

The phonograph (gramophone) record was invented in 1887 by German-born, American inventor Emile Berliner (1851-1929). His flat, rotating disc involved the stylus moving horizontally across the record rather than vertically, as with the cylinders used previously. Berliner's recording stylus cut down on sound distortion and was easier to manufacture than the cumbersome wax cylinders. Early phonograph records were made from a mixture of hard rubber, cotton, and powdered slate, although shellac (a form of commercial resin) was later used after its introduction in 1896. Phonograph records were initially single sided but the double-sided disc became common after about 1923. They usually came in three standard sizes, 7-inch, 10-inch, and 12-inch, and originally they revolved at between seventy-five and eighty revolutions per minute (rpm). Most producers eventually settled on 78 rpm. A 10-inch disc would record about three minutes of music on each side. The discs used a spiral groove to record the sound in an analog fashion. This groove began at the outer edge and slowly worked its way in toward the center. The sound was transferred from the disc using a sharp needle that was forced to oscillate at audio frequencies from side to side by the groove. The much loved long-play, 12-inch vinyl record was introduced in 1932. This revolved at 33 rpm, and twenty- five minutes of sound could be recorded on each side. Vinyl records were sturdier than their brittle shellac predecessors. Vinyl 7-inch, 45-rpm records took over from the shellac 78s with the advent of rock'n'roll. 

"Money cannot buy health, but I'd settle for a diamond-studded wheelchair." Dorothy Parker, writer After breaking his back in a mining accident , Herbert Everest so disliked his unwieldy wheelchair that he enlisted the help of an engineer friend, Harry Jennings, to help design a new chair. The device that Jennings came up with revolutionized the wheelchair market. Although wheelchairs had been in existence since the sixteenth century (the first one thought to be built for King Philip II of Spain), they had seen little development on their basic design until 1909. It was at around that time that the first lightweight models were made out of tubular steel rather than wood. These models had some foldable features, but it was the introduction of the folding X-brace frame that was the secret to Jennings's successful design. Beforehand, any wheelchairs that had foldable features used a T-shaped or an l-shaped frame. The use of a collapsible X-shape not only created a greater rigidity it also meant the wheelchair could be folded in by pushing the sides in toward each other with the wheels remaining fixed in place. In fact, this new wheelchair was so revolutionary that Everest and Jennings went into business together, launching the rather unimaginatively named Everest & Jennings Company. The company enjoyed massive success and market dominance in its early days, so much so that the U.S. Justice Department served it with an antitrust suit for attempting to monopolize the industry. 

U.S. inventor Otto Frederick Rohwedder (1880-1960) started working on the design of an automatic bread slicer in around 1912 and developed several prototypes, including one that held a sliced loaf together with metal pins. These early designs were not successful and Rohwedder faced a major setback in 1917 when his designs were destroyed in a fire at the factory at Monmouth, Illinois, that had agreed to build the first slicing machines. Rohwedder, having earlier trained as a jeweler, was employed by a security firm while working on the development phase of his invention in his spare time. He continued improving his designs and realized that the main challenge he faced was keeping the bread fresh, because after slicing the loaf went stale more quickly. By 1927 he had devised a machine that both sliced and wrapped the bread. The timing for the launch of the bread slicer was good: the pop-up toaster, invented in Britain in 1919 by Charles Strite, was just becoming popular in the United States. In 1928, the first of Rohwedder's bread-slicing and wrapping machines was installed at the Chillicothe Baking Co., which started to sell Kleen Maid Sliced Bread. Their customers loved sliced bread and demand for the machine from other bakeries had Rohwedder's production unit struggling to keep pace with orders. He established the Mac-Roh Manufacturing plant at Davenport in 1929 but was forced to sell the plant and his patents during the Great Depression. Demand for sliced bread continued to grow, however, and by 1933 bakeries in the United States were selling a greater quantity of sliced than unsliced bread. Today, approximately 80 percent of all bread is sold sliced. 

"[Heroin is] not hypnotic, and there is no danger of acquiring a habit." Boston Medical and Surgical Journal (1900) Throughout the nineteenth century, scientists sought a non-addictive substitute for the painkiller morphine. Morphine itself was first derived from the seeds of the white Indian poppy (Papaver somniferum) in 1803 by German pharmacist Friedrich Serturner. Heroin was first processed in 1874 by C. R. Alder Wright, a chemist working at St. Mary's Hospital Medical School, London. He boiled anhydrous morphine alkaloid with acetic anhydride over a stove for several hours and produced a more potent form of morphine, diacetylmorphine. But heroin only became popular after it was independently re-synthesized twenty-three years later by Felix Hoffmann (1868-1946), a German chemist working at the Bayer pharmaceutical company. When the drug was tested on Bayer workers, they said it made them feel "heroic," leading to the name heroin. From 1898to 1910 Bayer marketed heroin as a cure for morphine addiction, and as a component of cough pastilles and elixir because it decreased respiration. By 1899, Bayer was producing around a ton of heroin a year, and exporting it to twenty-three countries. Then, somewhat to Bayer's embarrassment, it was found that heroin is converted to morphine when metabolized in the liver, and is basically only a quicker acting, more potent form of the drug. In 1914 use of heroin without prescription was outlawed in the United States, with a court ruling in 1919 determining that it was illegal for doctors to prescribe it to addicts. Today heroin abuse is a serious problem for many countries in the world. Its use in medicine is also Strictly controlled for instances of severe pain. 

"If my films make even one more person feel miserable, I'll feel I've done my job." Woody Alien, movie director In just over 100 years, "moving pictures" have evolved from peep-show parlors into a vast, multibillion dollar industry that spans the globe. Today's movie industry has its roots in numerous nineteenth-century innovations. Thomas Edison sought to develop a device"... which does for the eye what the phonograph does for the ear." Attempts to duplicate the cylinder format of Edison's phonograph proved a dead-end, but Edison's "assistant," W. K. L Dickson, eventually developed the Kinetoscope for viewing pictures in a "peep-show" format, and the Kinetograph camera with which to create footage. The viewing method of this equipment, one person at a time, had obvious limitations, It was the Lu mi ere brothers—Auguste (1862-1954) and Louis (1864-1948)—who created the first practical film camera, projector, the Cinematograph. Despite the fact that it incorporated both projection and filming functions in one (and was a printer too), it was much smaller than Edison's large, bulky Kinetograph. The machine also had the massive advantage of projecting pictures that many people could view at once. It is this similarity to modern projectors that establishes it as the first proper film camera, projector. The first public showing, on December 28, 1895, featured ten short films including the Lumiere's first film Workers Leaving the Lumiere Factory. Each film was hand-cranked through a projector and lasted for approximately forty-six seconds. Film historians generally consider this historic 'screening at the Grand Cafe in Paris to mark the birth of cinema as a commercial medium. 

'Life is not significant details, illuminated by a flash, fixed forever. Photographs are." Susan Sontag, writer and critic Xenon flash lamps were pioneered by Harold Edgerton (1903-1990), a professor of electrical engineering at the Massachusetts Institute of Technology (MIT). He was an expert on the stroboscope as well as a creative photographer whose freeze-frame images are world famous. Xenon flash lamps, which are commonly used in photographic strobe lights, can produce an intense flash of light that lasts for between a millionth and a thousandth of a second depending on the volume and amount of gas in each lamp. The flashes can also be repeated up to a few hundred times per second. At a pressure of between 1 and 10 percent of an atmosphere, the xenon is contained in a sealed tube, usually of fused quartz. The discharge is triggered by switching a radio frequency high-voltage on to a small cathode, thus ionizing the gas. Then a short, thousand ampere pulse of current (from a charged capacitor) is passed through the tube, exciting the xenon atoms. These decay immediately, emitting the flash of light. Xenon is extremely efficient at converting electrical energy into visual radiation. The length of the flash is governed by the distance between the electrodes. Careful design of the electrode shapes and composition can ensure that the energy output of each flash is the same. The xenon flash produces a broad continuum spectrum topped with a host of spectral lines, but as these have wavelengths all through the visual spectrum, the light appears white to the human eye. Krypton can be used if more infrared radiation is required. 

"Our age is... a practical one. It demands of us all clear and tangible results of our work" Theodor Svedberg, chemist The centrifuge has been around since the mid-1800s. It is a device for separating a precipitate from a solution by spinning it at high speeds (the increased gravitational force means that anything suspended in the solution is forced to the bottom of the container much faster than if left to settle naturally). The first centrifuges were hand-driven, reaching speeds of 800 revolutions per minute (rpm). The first ultracentrifuge, developed by Swedish chemist Theodor Svedberg (1884-1971) in 1924, could rotate at speeds of up to 160,000 rpm, meaning it was capable of exaggerating gravity 1,100,000 times. In his first tests, Svedberg separated hemoglobin from blood in about six hours; using normal gravity it would have taken 180 years. The device's speed makes it a powerful analytical tool. It can measure a molecule's weight, size, shape, and density. It measures the movement of molecules at a certain rotational speed and this "sedimentation rate" is used to calculate the Svedberg unit (the velocity of the molecule per unit of gravitational field); this is used to work out the molecule's weight. Svedberg used his new technique to support the theories of Brownian motion put forward by Einstein and Von Smoluchowski, winning him the Nobel Prize in 1926. Nowadays, the ultracentrifuge proves useful for analyzing large molecules while still in solutions similar to those they naturally occur in.