Science Projects And Inventions

The image of a solar cell glistening in the sun illustrates many a magazine article on modern technology. But the means of converting light energy into electrical energy is nothing new. A "photovoltaic effect," whereby light hitting an electrode immersed in an electrolyte produces a current, was first observed in 1839 by A. E. Becquerel. This phenomenon was harnessed in 1884 when the first solar cell was built by American scientist Charles Fritts. Fritts used the less than economic design of semiconductive selenium coated in a thin layer of gold to achieve the conversion, at an efficiency of just 1 percent. The cell works by absorbing energy in the form of photons of light, which then displace electrons in the semiconductor, generating a current. Despite Fritts's optimism that the technology might replace centralized power plants, no one was ever going to power their home with only this kind of efficiency. more...

Before the arrival of the search engine, computers were linked together simply to let people transfer files between themselves. Those who had files to share set up a server, and those who wanted the files would come and get them. In time these servers clumped together, and having lots of files in one place made them easier to find. But even with clumping, files were spread out over the Internet. If you did not know the location of a file, it was very hard to track it down. This was the problem facing Alan Emtage (b. 1964), studying at McGill University in Montreal. With funding for software limited, it was Emtage's job to find free applications on the Internet for the university to use. At first he searched by hand, building a database of the software he had found, but eventually, being a computer scientist, he made a program to more...

“I put a new engine in my car, but forgot to take the old one out. Now my car goes 500 miles per hour." Stephen Wright, comedian As anyone who has ever tried to start up an old automobile will tell you, a choke is a miserable thing to operate. Pull it out too far and you flood the engine, do not pull it out far enough and the engine will not fire. It is not surprising, therefore, that automotive engineers did everything in their power to eradicate the need for carburetors. How did they do this? They invented fuel injection. Now commonplace on all production cars, fuel injection is an automatic, accurate way of keeping the engine's fuel-to-air ratio at suitable levels. Modern computer systems use precise sensors and gauges that react to very quick changes in operation, such as sudden accelerations to decide how much fuel is needed more...

"We may see and hear a whole Opera as perfectly as If actually present" U.S. Patent Office description for the Kinetoscope Motion pictures and even television may never have become a reality if it were not for the creation of the Kinetoscope by Thomas Alva Edison (1847-1931) and his deputy William Dickson (1860-1935) in 1891. The idea of moving still frames in quick succession to give the illusion of a moving image had already been demonstrated. Edison and Dickson took the principle and built a machine that could show long rolls of film. Edison was apparently inspired by a demonstration of the Zoopraxiscope, which used a fast-spinning disc with images around the outside to give the illusion of movement. Edison took it upon himself to develop a system that brought together moving images and sound; he called it the Kinetoscope. Edison set Dickson and his team to work on the more...

Home improvement work is risky business. Children's cartoons  serve  as continual  public  service announcements of the hazards of "do-it-yourself"—stepping on garden rakes and putting hammers through thumbs tend to top the charts in terms of accidents. For traveling salesman Peter L. Robertson (1879-1951), however, a real accident in 1906, when he put a sharp screwdriver through his hand, prompted him to find a way of avoiding such accidents. By 1908 Robertson was manufacturing a screw that was to revolutionize the industry. In Henry Petroski's book on the evolution of useful things he talks about the square-headed screw being invented to improve on existing designs—specifically the elimination or reduction of the risk of a slip. However, another improvement that Robertson made on the traditional screw was that his version could be fastened tighter than its rivals and operated with one hand—a very useful advantage for mechanics and other craftsmen alike. The more...

From the late 1890s Swedish inventor Carl Nyberg (1858-1939) was interested in solving the problem of manned flight. His numerous experiments with his Flugan (The Fly) flying machine generally proved unsuccessful, much to the amusement of local onlookers. Nyberg may not have suceeded in achieving his ambition of flight, but his flying machine was powered by a steam engine heated by four blowtorches, and it was the latter—a handy tool still widely used today—that he gave to the world. Nyberg, a prolific inventor who also worked on cookers, steam engines, and boat propellers, invented the blowtorch in 1881, although the actual patent application was made by business entrepreneur Max Sievert who showed an interest in Nyberg's invention and began selling it from about 1886. The blowtorch consists of a cylinder filled with fuel, usually propane, butane, or liquid petrol gas. This is vaporized and then mixed with oxygen (from the more...

"A pair of powerful spectacles has sometimes sufficed to cure a person in love." Friedrich Nietzsche, philosopher Bad eyesight has likely plagued humans since they first stood upright. Real solutions were not available until the thirteenth century when eye glasses were invented. Late in the 1880s, two eye doctors and a medical student independently invented contact lenses. Doctors Adolf E. Fick and Eugene Kalt set out to help their patients whereas medical student August Muller wanted to correct his own near-sightedness. Early lenses were literally a glass lens in direct contact with the eye. For their comfort and health, users could only wear them for brief periods as the lenses caused pain, swelling, and cornea hypoxia. Despite these drawbacks, more than 10,000 pairs sold in the United States from 1935 to 1939. By 1949, sales had reached 200,000 thanks to the plastic potymethylmethylpropenoate (PMMA) and Kevin Tuohy's 1948 invention of more...

"Great works are often born on a street comer or in a restaurant's revolving door." Albert Camus, writer The concept of a revolving door is not, for want of a better word, revolutionary. It is simply a rotating door made from several "wings" as opposed to one flat panel. But the architectural, social, and environmental implications of revolving doors are rather intriguing. The first patent for a revolving door was awarded to H. Bockhacker in 1881. Although they did not become commonplace until much later, several patent applications were filed for revolving doors before the close of the Victorian age. They included one filed by Theophilus Van Kannel in August 1888 for a three-winged "storm door structure" to guard against the elements. Van Kannel also highlighted the fact that his door only rotated in one direction and could therefore control the flow of people traffic and minimize the risk of more...

"The mirrored dome of an upturned Dewar flask is a thing of beauty, which every chemist should own." Andrea Sella, Royal Society of Chemistry website Needing a container capable of storing liquid forms of chemicals, Scottish physicist and chemist James Dewar (1842-1923) designed the vacuum flask that came to bear his name. In 1892, Dewar put one flask inside another and then sucked out the air between the flasks creating a vacuum. The double-walled vessel proved a superior insulator and perfect for a focus of Dewar's low temperature phenomena, and subsequently led to the invention of the Thermos® flask. For a few years, Dewar's flasks were on laboratory shelves not store shelves. The flasks' commercial potential was recognized by a glass blower employed by Dewar to fabricate the flasks, Reinhold Burger. He realized that Dewar's flasks could also prove useful for keeping food and drink either hot or cold. After more...

“I would rather that my spark should bum out in a brilliant-blaze than it be stifled by dry-rot.” Attributed to Jack London Spark ignition may be regarded as the process by which a farmer uses a cattle prod to put his herd in motion. It is also the process that enables an internal combustion engine to run on gasoline. Spark ignition works by passing an electric current through a carefully wired system and into a spark plug, which does what the first part of its name suggests by igniting the mixture of air and fuel in the chamber of the engine. In 1890 Karl Benz (1844-1929) sparked a new age of civilized society with the invention of spark ignition. This development in the automobile world—a world in which Benz was already famous for having invented the motorcar—made the gasoline-fueled internal combustion engine possible. Credit is also given to Oliver Joseph more...