Science Projects And Inventions

In 1919, long before the invention of electronic computers, a pair of British physicists invented the circuit that would become their key building block. William Eccles (1875-1966), who had pioneered the development of radio communication and assisted Guglielrno Marconi, together with Frank Jordan worked with the leading-edge electronic technology of the time—vacuum tubes, the predecessor of the transistor. Eccles was a radio pioneer, and his interest in vacuum tubes stemmed from their use in radio. In particular, the vacuum-tube diode was used to detect radio signals (the term "diode" was coined by Eccles). Experimenting with vacuum tubes, Eccles and Jordan found a circuit with an interesting property—it had a memory. Unlike other circuits whose output would change depending on what their inputs were doing, this "trigger" circuit would cling on to the last state it had been put in. The circuit had two stable states: a brief pulse applied to more...

"Some guy walked into the shop... with something like white syrup.He said, 'It's an acrylic.'" Leonard Bocour Otto Rohm studied acrylic plastics for his 1901 Ph.D. thesis. Six years later, he co-founded the Rohm and Haas Company, which in 1936 began selling shatter- proof acrylic glass (more commonly known by trade names such as Plexiglas®, Perspex®, and Lucite®). Sales were slow until World War II, when the United States began manufacturing tens of thousands of aircraft each year, all with Plexiglas® canopies. Chemists at Rohm and Haas had worked with acrylics for decades, but they were not the ones who invented acrylic paint. Instead, the inventor was an artist turned paint-maker. In 1941 Leonard Bocour (1910-1993) was making oil paint and selling it to artists when he was shown a sample of acrylic and was impressed by how white it was. After the war ended, Bocour worked with Rohm and more...

In 1937, Hungarian engineer Gyorgy Jendrassik (1898- 1954) designed and constructed a small turboprop engine. A year later he completed the larger "CS-1" engine, intending to use it on a military bomber, the RMI-1. Unfortunately, the CS-1 ran into combustion problems, keeping it from reaching its projected 1,000 horse-power. The RMI-1's designers were unable to implement an alternative engine before the RMI was annihilated in an air raid by the United States. In spite of its turbulent birth the turboprop engine enjoyed subsequent success. It is primarily distinguished by its namesake, the turbine-driven propeller at the front. Whereas turbojet and turbofan engines generate thrust only at their rears, the thrust of the turboprop engine is generated mostly by the propeller. The turboprop engine produces motion like any gas turbine engine. Air enters the engine and is compressed by a spinning, blade-covered cone called an axial compressor. The axial compressor pulls more...

A pulley is one of the simplest machines, essentially a circular lever in the form of a wheel or fixed curved block, with a groove around it to accommodate a rope or belt. The earliest evidence for the existence of the pulley comes from Assyria in the eighth century B.C.E. a painting of a battle scene shows a warrior using a simple pulley to lift a bucket over a wall. Pulleys are mainly used to move or lift a load. A single fixed pulley can be used to change the direction in which a force is applied, as it may be easier to pull on a rope than to drag or push the load. When the rope is fixed at one end and another pulley is added, the system effectively halves the required force, as each part of the rope carries an equal share of the load. This does not more...

"Somebody forgot the corkscrew and for several days we had to live on nothing but food and water." W. C. Fields, comedian and actor In 1795 the Reverend Samuell Henshall of Oxford, England, took the end of a gun worm—a steel, helix- tipped tool used for removing wadding and unspent charges from musket muzzles—and attached it to a wooden handle: he had invented the modern corkscrew. Between the handle and worm he added a unique concave button, designed to compress the cork. A series of ribbed protrusions on the underside of the button engaged the cork, breaking its adhesion to the bottle and preventing the cork from fraying. This so-called "Henshall button" also prevented the helical gun worm from penetrating too far into the cork. The corkscrew was manufactured in Birmingham by Michael Boulton, with the Latin phrase obstando promoves soho patent meaning "by standing firm one makes advancement," inscribed more...

"Technology has taken us from the rock, used to pound the clothes, to the modem rectangular washer." Lee Maxwell, Washing Machine Museum owner Washing clothes used to be work of drudgery, dubbed "the American housekeeper's hardest problem," but this problem has been largely solved by modern technology—in the shape of the washing machine. Throughout history, various devices—from the washboard to the mangle—have been invented to wash clothes more effectively and with less effort, but these still required manual labor by the user. In 1858, Hamilton Smith patented a rotary washing machine. Cylindrical, with "agitated water" and revolving paddles, it was a first step toward modern machines. Others followed from other manufacturers, some combining the machine with the mangle. These early machines were still hand-cranked, but it wa3 not long before motorized versions became available, either with fuel-burning or electric motors. It was not until the early 1900s, however, that the more...

When the great Islamic scholar AI-Jazari (1150-1220), published in 1206 his Kitab fi ma'rifat al-hiyal al- handasiyya (Book of Knowledge of Ingenious Mechanical Devices], it included a description of a device that could change rotational motion into reciprocating motion: the camshaft. This invention consists of a shaft that has oval-shaped lobes attached to it, which turn with the shaft itself. Because of their noncircular shape, these "cams" appear to oscillate when the shaft spins on its axis. If a cam is positioned next to a valve, as it is in the example of the internal-combustion engine, then, as the camshaft turns, the longest end of the cam will depress, and hence open, the valve each time the shaft makes a turn. Before that, the camshaft played an important role in many medieval technologies. In windmills and waterwheels, for example, camshafts transformed rotational power into the energy and modes of action more...

"Nobody outside of a baby carriage... believes in an unprejudiced point of view." Lillian Hellman, playwright The first known design for a baby carriage was produced in 1733 by William Kent (c. 1685-1748), the renowned English landscape-garden designer. Today the baby carriage is an essential tool for any family with children, but it was originally intended as an entertainment. Kent, who as a designer could turn his hand from furniture to ladies clothes as well as gardens, was commissioned by the third Duke of Devonshire to design something to amuse his children. He produced a shell-shaped vehicle in which a baby could sit, with an attached harness designed to fit a small pony, a dog, or a goat. Baby carriages quickly became popular among the wealthy as fashionable toys. Gradually changes were made to their design, with one of the most significant being the addition of handles, which allowed a more...

Archeologists have found a model of a loom in an Egyptian tomb from 4,000 years ago. Yet the development of loom technology was slow until 1733, when John Kay (1704-1780) invented the flying shuttle. Looms interlace two sets of yarn or threads together to form cloth. The first set of threads is placed lengthwise along the loom and is called the warp. The second set of threads is called the weft. The weft is carried between the warp threads by a shuttle. In traditional looms, weavers passed the shuttle through the warp by hand, and it was a slow process. Kay's flying shuttle moved on wheels in a track through the warp when the weaver pulled a cord. This was much faster than hand weaving, and could also be used to create much wider fabrics than previously possible. Kay did not receive much benefit from his invention because weavers saw more...

“…and [Adam] slept: and [God] took one of his ribs, and closed up the flesh instead thereof.” Genesis 2:21 Many breakthroughs made in modern medicine, such as open heart surgery or joint replacements, would never have been possible in a world without pain control. But how did anesthesia develop? As it turns out, early physicians never, to the best of our knowledge, resorted to knocking people out prior to performing surgery. Ancient Egyptian and Assyrian physicians compressed both carotid arteries at the same time, limiting blood flow to the brain and so inducing loss of consciousness in patients for the purpose of conducting a procedure. In addition, the Egyptians discovered that opium could help to ease pain, and the Assyrians used their own painkilling mixtures of belladonna, cannabis, and mandrake root. The Greeks and Romans copied and developed these techniques, and medieval Arabs even developed a form of inhalational anesthesia. more...