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 more...

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 more...

"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 more...

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 more...

"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. more...

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 more...

"[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 more...

"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 more...

'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 more...

"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 more...