Science Projects And Inventions

"If you cannot saw with a file or file with a saw, then you will be no good as an experimentalist." Augustin-Jean Fresnel French physicist Augustin-Jean Fresnel (1788-1827) was extremely interested in the properties of light. He published a number of papers on optical phenomena such as aberration and diffraction, but he is best remembered today for an invention that turned his love of physics into a practical and revolutionary device: the Fresnel lens. Essentially he created a new type of lens that performed in the same way as a traditional one. Fresnel's design, however, was much lighter, which made it a practical option for making the large lenses needed for lighthouses. Some of the lighthouse lenses were more than 12 feet (3.6 m) tall and looked like giant beehives. The greatly improved efficiency with which these lenses could capture light meant that up to 83 percent of the light more...

The invention of the tin can in 1810 was something of a revolution in the food industry, particularly for the armed forces and explorers. The only problem was how to open them. They were so thick and heavy that opening them was difficult, and was usually done with a hammer and a sharp instrument. In the 1850s cans were produced using thinner steel, and in 1858 the first can-opener patent was issued to Ezra Warner of Connecticut who devised an opener with a pointed blade and a guard to keep the blade from penetrating too far into the can. In 1868 J. Osterhoudt patented the keyed type of can opener used for sardine cans. It was not until 1870, however, and the efforts of William Lyman—also from Connecticut—that the "modern" version of the can opener came along. Perhaps driven by an insatiable desire to taste the contents of a can more...

In 1777 Samuel Miller of Southampton, England, received the first patent for a circular saw. His wind- powered machine's usefulness was limited, however, for want of a more powerful energy source. Thirty-six years later Tabitha Babbit, a Shaker woman from the Harvard Shaker village, invented a circular saw of her own. Her religious beliefs prevented her from seeking a patent, but the new invention became popular in her community. Babbit's saw was initially human-powered, but waterwheels and steam were soon harnessed for added convenience and efficiency. Sawmills adopted the circular saw, and the tool was soon at the heart of the lumber industry. The circular saw is a relatively simple device that dramatically improves on the efficiency of a standard handsaw, where half of each stroke is wasted effort. Circular saws cut by spinning circular serrated blades at high speeds into the timber passed through them. The U.S. military, bolstering more...

A jet engine uses a fan to suck air into a cylindrical chamber and a second turbine fan to compress it. Then fuel is mixed with this high-pressure air and ignited. The hot expanding burning gasses then blast out of a nozzle at the rear of the engine thrusting the engine forward, and the aircraft it is usually attached to, with great force. The independent coinventors were the English aviation engineer Sir Frank Whittle (1907-1996) and the German airplane designer Dr. Hans von Ohain (1911-1998). Chain's engine was tested in the Heinkel He178, flying first in August 27, 1939. Whittle's first engine, the Whittle Unit (WU), was completed in 1937 and subsequently fitted to an aircraft called the Pioneer (E.28/39), built by the Gloster Aircraft Company. The first flight was on May 15, 1941. World War II saw swift developments of the jet engine and airplane. The United States's Bell more...

"One would think that... those purple ribbons were synonymous with ‘Per kin for Ever.'" All The Year Round, contemporary weekly journal In 1856 eighteen-year-old William Henry Perkin (1838- 1907) was assisting August Wilhelm von Hofmann at London's Royal College of Chemistry. Hofmann's particular interest lay in making synthetic versions of natural substances. Toiling away in a fume-filled, makeshift laboratory at the top of his London home, the young assistant was trying to synthesize the anti- malarial medicine quinine, which involved him working with coal tar. When a black sludge formed in the bottom of a flask he started to clean it out by adding alcohol and shaking up the mixture. A beautiful bluish color appeared. When tested on silk, Perkin found that it was a rich, purple, fast dye—the first synthetic dye after millennia of natural dyestuffs that often faded, ran, or were costly to produce. By experimenting with a more...

Following a series of controlled-flight-into-terrain (CFIT) crashes in the 1960s, where aircraft had crashed simply because their pilots did not realize how close to the ground they were flying, Donald Bateman {b. 1932) designed a Ground Proximity Warning System. The system works by collating data from the radar altimeter (which measures the height above the ground), the barometric altimeter, the sensor that detects the glide path, and sensors attached to the flaps and landing gear. The data are then used to predict trends in flight pattern. The pilot is warned if the system registers an excessive descent rate, excessive terrain closure rate, altitude loss after take-off, unsafe terrain clearance, or below glide path deviation. Each of the five danger modes has its own audio and visual warnings to alert the pilot. Within each mode, there are also different warnings depending on the severity of the deviation. For example, a sink more...

With the onset of the Industrial Revolution in the late eighteenth century, engineers began to harness steam power for many vehicles, including ships. Treadmill- driven paddles had been used since antiquity, and prototype paddle steamers began to appear in the 1780s. But a parallel technology was about to emerge, or perhaps submerge, in the shape of the screw propeller. This acted entirely underwater, as opposed to the paddle which was only partly below the surface—an obvious advantage in a naval battle, with cannonballs flying around. There is still controversy over who can claim credit for the marine propeller. James Watt proposed steam-driven propellers in 1784, but never built them. Many others took out patents on the concept, although none led to a practical device. The first truly useful screw propeller, and the first to place the screw between the ship's helm and the stern, was developed by Bohemian engineer Josef more...

The use of rockets in warfare began with the Chinese, who first developed the technology around the thirteenth century. Their new "fire arrows" were successfully deployed against the Mongols, and it was not long before the rest of the world began to experiment with them. During the eighteenth century, the British and the French were fighting over India, each keen to possess its riches. Unfortunately for them, they discovered that the inhabitants were not always happy to hand over their land. Tipu Sultan of Mysore in southern India fought the British with a lactic, developed by him and his father, of using rocket brigades against the British infantry. The Mysoreans perfected the use of the rockets in the battlefield, developing the technology so that they could fire them over much greater distances than British weapons could achieve. The European rockets were wooden, so they could only survive so much thrust more...

"Mr. Castro [was a] genius not only at designing a piece of furniture... but at marketing his product." Dennis Hevesi journalist In Depression-era America, Sicilian immigrant Bernard Castro (1904-1991) spotted a niche in the market. Noting that New Yorkers did not have much money to spend on luxuries and that their apartments in the city were cramped, he proposed a bed that could be folded into a sofa during the day, significantly increasing available living space. Naming the beds "Castro's Convertibles," he sold them from his loft store P.N Twenty-first Avenue. The only convertible sofa otherwise available was known as a davenport, which was difficult to open and close and did not look like a sofa when folded. One night Castro and his wife found that their four-year-old daughter had managed to open their convertible; they realized that this could be a major selling point. Castro's other masterstroke was recognizing more...

The black box flight recorder, now a required feature on all aircraft, was the brainchild of Australian aviation scientist David Warren (b. 1925), whose own father was killed in a plane crash in 1934. After World War II, there was a massive rise in commercial air travel, but after several planes came down in unexplained circumstances, the public's confidence in flying was understandably shaken. In 1953, Warren was part of the team investigating the crash of the world's first jet-powered passenger plane—the Comet. He thought how useful it would be to have an account of the events inside the plane during the last moments before it came down, and so he set out to develop a crash-proof device that could record sound and instrument readings in the cockpit. He built a prototype called the "ARL Flight Memory Unit" that could record up to four hours of speech onto steel wire. more...