Current Affairs Science Projects And Inventions

"All technology can be used for bad or good. It's up to you how to use it." Vladimir Zworykin, scientist In 1930, the Soviet Russian physicist Leonid Kubetsky (1906-1956) proposed a method to amplify weak photoelectric currents. He exploited the photoelectric effect where the energy of photons is converted into the energy of moving electrons. These electrons can then be accelerated. When these electrons impact a fluorescent plate, several photons are then dislodged, converting the energy back into visible light. The device, a photomutliplier tube, can increase the illumination fifty-fold. Used in series, these tubes can create a cascade of photons, producing gains in excess of 50,000-fold illumination. In the 1930s, Vladimir Zworykin (1889-1982) was working at RCA on what became the first commercially viable television. To overcome the problem of a weak signal, Zworykin employed a similar photomultiplier. It was Zworykin's design, produced in 1936, that became commercially successful, and Kubetsky is largely forgotten outside of the former U.S.S.R. The military quickly saw the potential of these devices. Working with G. A. Morton, at RCA, Zworykin developed the first generation of night vision devices. These devices sensed infrared light, which is invisible to the unaided human eye. The photomultiplier tubes found use in astronomy in 1937 so that the weak visible light from distant stars could now be seen. The tubes were also employed in medical imaging. 

"The Cadillac car will kill no more men if we can help it. We're going to develop a fool-proof device... " Henry M. Leiand, founder Cadillac Automobile Co. Before the invention of the starter motor, the motorist had to indulge in some energetic "cranking" of the engine with a starting handle before it would fire. Sometimes the engine would misfire, Jerking the handle violently and injuring the hapless motorist. Automatic starters had been proposed some years before—a patent for what turned out to be an impractical solution was granted to Clyde J. Coleman in 1903. Research into a practical system was revisited with some urgency when a friend of Cadillac's founder, Henry Leiand, died following an injury sustained when a starting handle, thrown by a backfiring engine, struck him in the face. Cadillac called upon Charles F. Kettering's (1876-1958) company, Dayton Engineering Laboratories (DELCO)—an entity set up specifically to exploit Kettering's already proven success in automotive electrical design—for help. Kettering realized that an automobile starter motor need only operate successfully for a few seconds at a time, so it need not be impossibly large. The unit he developed was a combined starter motor and generator. First installed in a Cadillac on February 27, 1911, it incorporated an over-run clutch and reduction gear and could thus provide enough torque to crank the engine quickly and disengage once the engine fired. Car ownership was revolutionized. 

"A pencil and rubber are of more use to thought than a battalion of assistants." Theodor Adorno, philosopher and musicologist Hevea brasiliensis—otherwise known as the "rubber tree"—had been tapped for thousands of years to harvest its saplike extract (latex, the source of natural rubber) long before anyone knew what rubber was. Rubber's chemical composition was finally cracked by British chemist and physicist Michael Faraday (1791-1867) in 1829. Faraday determined natural rubber's basic chemical formula—C5H8—a molecule that was later named "isoprene." Rubber is composed of many isoprene units strung together, forming a polymer—polyisoprene. Attempting to mimic the natural product of Hevea brasiliensis, scientists set out to reproduce polyfeoprene in the laboratory—and met mostly with failure. Fed- up with isoprene, scientists ditched it for butadiene (C4H6), hoping the change would be more successful in yielding a synthetic polymer similar to rubber. Working in St. Petersburg, and using ethanol to make butadiene and sodium to kick-start the polymerization, Russian-Soviet chemist Sergey Lebedev (1874-1934) cooked up polybutadiene, producing the first fake rubber in 1910. By the 1940s, the Soviet Union had the largest synthetic rubber industry in the world. The discovery of polybutadiene, which is known today as butadiene rubber (BR), sparked the synthetic rubber industry. Other synthetic rubbers followed BR; styrene-butadiene rubber (SBR) in the 1930s and silicone rubber (SR) in the 1940s. By the end of the 1960s, synthetic rubber had natural rubber on the ropes, and today synthetic rubber beats natural rubber in both production and usage. All thanks to Levedev who showed us how to fake it. 

"The maximum warmth produced by the two heaters [was] literally sufficient to roast an ox..." The Evening Journal (August 29, 1892) From the eighteenth century, people began to cook with stoves rather than using open fire, which was dirty, dangerous, and inefficient. The first electric stove was a little longer in coming, although exactly who invented it and when is a matter of some debate. Although  the  Carpenter  Electric  Heating Manufacturing Company produced an electric stove in 1891, the first patent for an electric stove was granted to William Hadaway in 1896. Another claim to the invention comes from Thomas Ahearn (1855- 1938), a Canadian businessman and inventor, who set up the Ottawa Electric Company in 1882. Ahearn was reputedly the first person to cook a meal using electricity in 1892. The early electric stove worked by running electricity through a resistance coil; the coil heats up, which in turn heats up an iron plate upon which a cooking vessel, with food inside it, sits. Today electric hobs use glass-ceramic tops instead of iron and the heat often comes from a halogen bulb instead of a resistance ring, but the principle is basically the same. The electric stove was slow to take off because few people had access to electricity at the time, A fully electric kitchen was unveiled at the Chicago World's Fair in 1893, and featured an electric stove. But, it was not until the 1920s that the electric stove began to be a serious competitor to the gas stove. 

"If the only tool you have is a hammer, you tend to see every problem as a nail." Abraham Maslow, psychologist The use of hand tools by humans has undeniably been a major factor in our evolution from hunter-gatherers to builders of civilizations. On many occasions a new design of tool has come at just the right time to add a boost of acceleration to the history of our technology. The invention of the pneumatic hammer was one of those very events. Charles Brady King (1869-1957) had an eclectic range of interests. He considered himself a mystic, as well as a musician, artist, poet, and architect. He also had a degree in mechanical engineering from Cornell University, New York. His invention of the pneumatic hammer was perfectly timed. The 1890s were a time of rapid growth in construction, shipbuilding, mining, and the new automotive industry. Any invention that increased the productivity of workers was bound to be a success. King's hammer used the power of compressed air and was extremely simple in concept. The input of the compressed air would drive a piston forward with great power, and this could be attached to any tool that required a to-and-fro percussive movement, such as a hammer. It was perfect for adding large numbers of rivets in construction, as well as for caulking. King demonstrated his invention at the Chicago World's Fair in 1893 and went on to focus his energies on the car industry. His pneumatic hammer was further developed by what was to become the Chicago Pneumatic Tool Company. A famous iconic painting showing a female worker with a pneumatic riveter became a symbol of courage during World War II. The painting Rosie the Riveter by Norman Rockwell (1943) was sold in 2002 for $5 million. 

During the American gold rush (1848-1855), people flocked from all over the world to California with dreams of finding great wealth. Lester Pelton (1829- 1908) of Ohio was one of these migrants, but it was not in gold that he found success. It was with his free- jet water turbine, which he first patented in 1880, that he found fame and fortune. Gold mining was becoming a large-scale industry and required ever-increasing amounts of power. As firewood supplies dwindled, steam power became very expensive and mining companies looked for an alternative energy source in the creeks and waterfalls surrounding the mines. In 1866 Samuel Knight invented a water turbine that replaced the paddles of water wheels—like those used in rivers to power flour mills—with cups to catch jets of water directed from above. While watching a misaligned turbine, Pelton noticed that the water ran down the edge of the cup rather than hitting the middle, making the wheel turn faster. This is because the amount of force generated by the water jet increases with the distance over which it is applied. To take advantage of this, Pelton split the cups In two with a metal wedge so that the water would hit the wedge and move down on either side and thus travel further. Pelton's design—the Pelton wheel—was more than 90 percent efficient, an improvement of about 14 percent on its closest rival. The Pelton wheel remained the standard for decades and was the basis for later water turbines. These are still manufactured today, and many Pelton wheels still function around the world. Maybe the search for renewable energy sources will spark a revival in this method of water power. 

"Will you have some microbe? ... The Microbe alone is true, and Pasteur is its prophet." French journalist mocking Pasteur in 1881 In the 1870s, French microbiologist Louis Pasteur (1822-95) was still trying to disprove criticism of his germ theory. He had reported that boiled fluids, such as broth and urine, do not support bacterial growth if kept free of contamination. The British physician Harry Bastian, an outspoken critic, countered that boiled urine could indeed grow bacteria. Pasteur realized that to prove his germ theory, he needed to achieve temperatures greater than 212°F (100°C) and charged French microbiologist Charles Chamberland (1851- 1908) with creating such a device. Chamberland knew that if water were boiled under pressure, it could reach 250°F (121°C). Fifteen minutes at this temperature killed all known bacteria. He devised an autoclave, or "self lock," in 1879, for sterilizing surgical instruments. Chamberland's device was based on the 1679 "steam digester" of Denis Papin—the first pressure cooker. Both the autoclave and the pressure cooker remain in use today. Sadly, the autoclave does not protect against the food-borne pathogen leading to "mad cow disease" or the variant Creutzfeldt-Jakob disease because prions, the causative agent, can survive ordinary autoclaving temperatures. 

"When you hunt... you may succeed or not. When you open the fridge, you succeed [all] the time." Nora Volkow, National Institute on Drug Abuse The refrigerator is one of the key inventions of the twentieth century. Its use in food storage is vital, slowing the development of bacteria and keeping food edible for much longer. Before its invention, the only source of cold was blocks of ice, which could be bought in some places and used with a cool-box. Most homes had no means of chilling food. Baltzar von Platen (1898-1984) and Carl Munters (1897-1989) were; students at the Royal Institute of Technology in Stockholm, Sweden, when they collectively invented and developed the gas absorption refrigerator. Unlike modern fridges, the invention did not require electricity driving a compressor, but relied instead upon an ingenious process whereby a refrigerant gas is put through a series of changes of state. In von Platen's process, ammonia mixed with water is heated until the ammonia evaporates. This gas is then passed through a condenser, which conducts heat away from the pure ammonia until it becomes liquid at a much lower temperature than when mixed with water. This liquid is then passed through brine and cools it, which in turn chills the unit. The ammonia is then returned to a gas and reabsorbed into water so that the process can begin again. The gas absorption refrigerator went into production in 1923 by AB Artic (later purchased by Electrolux), but it never truly caught on. The electric refrigerator, developed at the same time, gained much more investment and advertising and soon came to dominate the market. By the 1930s, the gas absorption refrigerator had ceased to be produced. 

"Applications of science to warfare and materialistic enjoyment mil be the downfall of mankind^ Edouard Branly The science behind the coherer had long been observed by various people before anybody actually managed to put it to any practical use. The effects of electrical charge on small specks of certain matter,' such as dust, was noted in around 1850 by a man named Guitard. He spotted that when dusty air was electrified, the particles of dust would gather together to form a sort of stringed formation. It was not until 1890 that Edouard Branly (1844-1940) found a way for this unusual phenomenon to be exploited. Experimenting with thin pieces of platinum film on glass, Branly discovered that there was a massive variation in the film's electrical resistance when it was subjected to electromagnetic waves (known at the time as Hertzian waves, known today more commonly as radio waves). This discovery led Branly to create the coherer—a piece of equipment that consists of little more than a few metal filings lying loosely between two metallic electrodes in a glass tube. In its normal state, the coherer has a huge resistance. In the presence of Hertzian waves, the filings allow current to pass through them. Connected to a circuit, the coherer can then be used to detect electromagnetic signals. This device became the basis of radiotelegraphy and was used in the development of wireless telegraphy, most notably by Marconi. 

The first job German-American statistician Herman Hollerith (1869-1929) had was with the U.S. Census Bureau. His task was to collate information gained from the 1880 census by hand and he quickly realized that the process would be much faster and less prone to error if it was automated. Trying to work out a solution to the problem, he arrived at the idea for a system based on punchcards while observing a bus conductor punch holes in tickets. He filed his first patent in 1884. The punchcards were not entirely novel—the French weaver Joseph-Marie Jacquard had invented a way of controlling the warp and weft on his loom by patterns of holes in cards—but Hollerith's design for a tabulator and sorter were original. The information was read from each card using an array of spring-mounted brass pins that formed an electrical connection through any holes in the card. The tabulator then had many output dials that could display the information contained on each card. In addition to reading information, the sorter part of the machine enabled the operator to select for certain characteristics such as sex, marital status, or profession using an array of switches. Cards that matched the specified criteria would be automatically gathered in a special container, allowing statisticians to gather data to their hearts' content for the first time. Hollerith's machine was used in the 1890 census and reduced the time spent collating the data by over half, saving the country $5 million. Hollerith formed the Tabulating Machine Company in 1896 to market his invention, which in 1924 changed its name to International Business Machines (IBM). His system was used In computers until the late 1970s.