Science Projects And Inventions

"The skyscraper establishes the block, the block creates the street, the street offers itself to man." Roland Barthes, literary and social theorist Before the advent of the skyscraper, tall buildings were built to showcase great wealth, power, or religious beliefs. For the architect and civil engineer William Le Baron Jenney (1832-1907), the urge to build great edifices was born from a necessity to solve commercial (and later residential) needs in his native Chicago, where ground space was at a premium. Two obstacles to the construction of highrise buildings were overcome in the mid-nineteenth century, paving the way for the skyscraper. In 1853 Elisha Graves Otis devised a mechanism to prevent elevators from falling if their cable broke, enabling passengers to be transported upward safely. The second breakthrough came with a steel-framed structure that could support the entire weight of its walls, instead of the traditional load-bearing walls that carry the more...

“You're talking about desire. The name of that... streetcar that bangs through the Quarter." Tennessee Williams, A Streetcar Named Desire (1951) To this day the tram remains the least glamorous of all methods of public transport, but at least American electrical engineer Stephen Dudley Field (1846-1913) tried to give the humble vehicle a little more pizzazz. Field was not issued with a patent for his system of propelling railway cars by electromagnetism until 1880, even though it had been installed in New York City in 1874 by the twenty-eight-year-old inventor—a man often called the "father of the trolley car." The innovative method of providing electricity to the onboard motor worked by having a dynamo generate a current, which was conveyed via two metal wheels that linked the motor with either one of the rails. The system was pretty ineffective and actually highly dangerous, but it marked an important change in more...

“It’s essential to recognize that no tool... can approach the vastness of the universe and life itself." Hanz Decoz, numerologist                        In appearance it is a simple piece of metal with a hexagonal cross-section and a ninety-degree bend about three-quarters along its length. Called variously Hex key, Alien key, Alum key, Inbus, and Unbrako key, this uncomplicated device may date back to the 1920s. The Unbrako company developed a hexagonal-head key and screw in the 1920s which went on to become popular in the United States and Britain. During the same decade'it is claimed that Italian Egidio Brugola, founder in 1926 of Brugola manufacturing company, also created a hexagonal- head fastener, which was the foundation for a business that still thrives today. In Italy (unsurprisingly) the Alien key is called the "Brugola." A couple of decades later, in 1943, the more...

U.S. computer scientists Carl Kesselman, lan Foster, and Steve Tuecke had the bright idea that computers could be loosely coupled together to provide massive computing ability just as power stations can be linked to supply extra electricity. With computer grids and power grids the consumer does not have to worry about the source or the location of the input. Different types of computers can be incorporated and these may be located all over the world. Your own computer can be used in a grid when you are asleep, during lunch breaks, or even at random moments during the day when the computer is waiting for input. High-speed interconnections are usually not available and so the system works best on problems where independent calculations can be carried out without the participating processors having to communicate. Needless to say, software has to be carefully designed to check for untrustworthy, malfunctioning, and malicious more...

"We recognized almost at once that the material was different and that It had potential... “ Lois Plunkett In 1938 research chemist Roy Plunkett (1910-1994) was working at the DuPont Jackson laboratory in New Jersey. He had been trying to improve refrigerants to make them nontoxic and nonflammable. Plunkett and his technician Jack Rebok had produced 100 pounds (45 kg) of tetrafluoroethylene gas (TFE), storing it in cylinders on dry ice. When the time came to use the material, nothing came out of the cylinder, even though it weighed the same as before. The gas had turned into a white powder. Plunkett and others at DuPont found that the substance was quite slippery and proved to be a good lubricant. It was resistant to chemicals and heat, and other substances would not adhere to it. The material was resistant to temperatures as high as 500°F (260°C). Plunkett and his colleagues more...

Man has cultivated the Earth for thousands of years, and for a large portion of that time he has been "tilling"—turning the soil to bury weeds and mix in fertilizer—in order to grow crops. Tillage, and agriculture in general, took a big step toward modern intensive processes when Australian inventor Arthur Clifford (Cliff) Howard (1893-1971) created the motorized tiller—the Howard Rotovator—in 1912. The son of a farmer, Howard studied engineering in Australia at Moss Vale, New South Wales. In 1912 he began experimenting on farming methods—primarily machines to improve tillage—on the family farm at Gilgandra, New South Wales. Howard noticed that regular plowing methods compacted the soil, making it more difficult to mix in fertilizer. Rotary tillage already existed, but was operated manually. Howard took a standard manual tiller and coupled it to his father's steam tractor. This proved superior to the standard plowing techniques, taking less effort to run, more...

Both waterproof and airtight, cellophane is now used for everything from food packaging to sticky tape. The man who invented it—Swiss textiles engineer Jacques E. Brandenberger (1872-1954)—initially wanted to develop a clear coating for cloth to make it waterproof after witnessing a wine spill on a restaurant tablecloth. He tried coating cloth with a thin sheet of viscose, but viscose made the cloth too stiff. The transparent sheet of film separated easily from the cloth and Brandenberger soon realized that the film itself had more potential than the waterproofed cloth. To create cellophane, Brandenberger dissolved cellulose fibers from materials such as celery, wood, cotton, or hemp in alkali and carbon disulfide to make viscose, which is then extruded through a slit into an acid bath to reconvert the viscose back into cellulose. The acid regenerates the cellulose, which forms a film, and further treatment—for example washing and bleaching—produces cellophane. (Rayon more...

Spectrophotometers are used to measure the intensity of electromagnetic radiation. Usually the measurements are confined by filters to a very narrow spectral range and the instrument is used to detect the change in brightness after the light radiation has either passed through a sample or been reflected off it. Early devices used the naked eye to determine the differences in intensity between two beams. Arthur Hardy (1895-1977), a physicist at the Massachusetts Institute of Technology, decided to replace the eye with the new cesium photocells, and thus detect intensities electronically. The plan was to produce a Spectrophotometer that automatically scanned through the visible spectrum and produced a pen-drawn spectrum showing how the light intensity varied with wavelength. Beam splitters and rotating polarizers were used and the two beams were compared by blinking quickly from one to another using a flicker photometer technique. Working in collaboration with the firm General Electric, more...

"What then is time? If no one asks me, I know what it is. If I wish to explain it, ...I do not know." Saint Augustine, theologian A time zone is a longitude band around the globe in which everyone sets their clocks to the same time— regulated by the movement of the sun. Before time zones were introduced, every town kept its own local time. But with the advent of the railways this system became very inconvenient, as the time at the starting point of a journey might well differ from the one at the terminus. In 1847 the railway companies in Great Britain recommended that all docks should be set using the same time marker. Noon on the Greenwich Meridian (0 degrees longitude) was chosen, which is known as Greenwich Mean Time (G.M.T.). Because Earth spins every twenty-four hours, local time varies by one hour for every 15-degree more...

Doctors treating polio patients found that while many sufferers were unable to breathe in the acute stage, when the action of the virus paralyzed muscles in the chest, those who survived this stage usually recovered completely. Such observations indicated the need to develop strategies to maintain respiration until the patient could breathe independently again. In 1927, chemical engineers Philip Drinker (1894-1972) and Louis Agassiz Shaw, from Harvard University, devised a tank respirator to maintain respiration. In the device, the patient's head stuck out of the end of the tank, with a sponge rubber seal to make it airtight. Air was then pumped from the tank to produce negative pressure causing the chest to expand and thus produce breathing. The first iron lung was installed in 1927 at Bellevue Hospital, New York, and in 1928 the first patient was an eight-year-old girl with polio, comatosed from lack of oxygen. One minute more...