Science Projects And Inventions

Dennis Ritchie [b. 1941) is idolized by computer programmers all over the world. Why? Because he wrote what is, without a doubt, the most widely used programming language in the world. After gaining undergraduate and graduate degrees from Harvard, Ritchie went to work for Bell Laboratories in 1968. It was there, alongside Ken Thompson (b. 1943), that he created the UNIX operating system. At the time, Bell Labs was using a programming language called "B," which was used to write UNIX. Building on this operating system, Ritchie, in his own words, "added data types and new syntax to Thompson's B language, thus producing the new language 'C.'" This new language, designed to be used with the UNIX operating system, is general purpose and, critically, was written to allow ft to be "ported," or transferred from one type of computer to another. At the time, Ritchie and Thompson had been working more...

When beer is stored in large quantities—in the cool cellar of a bar or pub, for example—it can be retained in the casks in which it was delivered, where its continued fermentation improves the taste and strength of the drink. When the cask beer is eventually drawn out by a pump, it mixes with nitrogen in the air and gains its characteristic texture and head. Guinness Irish s-tout is unusual in that its distinctive head is caused by special taps that ensure a precise mix. When brewers started putting beer in bottles so that it could be drunk away from the cask, they found that the fermentation in bottles caused a much higher level of carbonation. All this carbon dioxide is good because it leaves no room for oxygen in the bottle, which would sour the beer, but it creates a much fizzier drink. Without the taps to pour the more...

"The real danger is the gradual erosion of individual liberties through automation..." U.S. Privacy Protection Study Commission, 1977 Building on a concept proposed by Jacques de Vaucanson in 1745, Joseph-Mane Jacquard (1752- 1834), namesake of the famous loom, perfected a more practicable interpretation of his fellow Frenchman's idea—automation using punched cards. Jacquard knew from experience that silk weaving, although a skillful art, was extremely repetitive. It was this aspect of the process he attacked and so he set out to control the weaving process by linking the actions of the loom to the pattern of holes on the cards. Each card had the same number of rows and columns, the presence or absence of a hole being detected mechanically and thereby determining the loom's movements. Ultimately, many such cards would be connected in sequence, enabling the loom to weave complex designs time and time again. In 1803 Jacquard was summoned more...

"Business opportunities are like buses, there's always another one coming." Richard Branson, British entrepreneur Londoner Obadiah Elliot invented the leaf spring in 1804 when he piled steel plates on top of each other, pinned them together, and attached them to the end of a carriage. His design remains a key component in supporting heavy goods vehicles, however, he was not the first person to add a bit of spring to transportation, Ancient Roman vehicles were suspended on elastic wooden poles, which work on the same principle. The spring is formed by stacking several layers of steel in the shape of an arc with an axel in the center and the edges tied to the vehicle. What has made the leaf spring such a popular invention is that varying the number of leaves (steel plates) or the curvature of their configuration alters the performance and weight capacity of the spring. They more...

The need for a sealed face mask to protect against the inhalation of smoke and airborne toxins became apparent with the development of underground mining in the eighteenth century. A crude respirator was invented by the Prussian naturalist Alexander von Humboldt in 1799 while he was working as a mining engineer. Other designs included Garratt Morgan's "Safety Hood and Smoke Protector," developed in 1912, consisted of a cotton hood with two hoses reaching down to the floor, where cleaner air would often be found. But the crucial imperative in the development of an effective gas mask was the use of poison gas, especially chlorine. This gas was used for the first time in World War I by the German Army at the Second Battle of Ypres in April 1915. Initial attempts to counteract the chlorine gas using cotton mouth pads and absorbent hoods proved either ineffective or cumbersome and thousands more...

"Whatever happened /To Tuesday and so slow/Going down the old mine/With a transistor radio." Van Morrison, "Brown Eyed Girl" When the transistor first appeared in 1947, few could have guessed how it would quickly transform the world of consumer electronics. The transistor was the size of a fingernail, weighed practically nothing, and was a direct replacement for the bulky, delicate electricity-powered glass valve. Suddenly, electronic circuitry was able to shrink to a fraction of its former size and be powered by small DC (direct current) batteries. The first popular consumer product to take advantage of this miniaturization was the transistor radio. Although there had been a number of small portable models appearing at trade fairs in Europe and Japan, the 1954 Regency TR-1 was the first to go into mass production. The technology behind the Regency transistor radio came from an innovative U.S. electronics corporation, Texas Instruments. They had designed more...

"The ground was covered by some dark stuff that silenced all the wheels. ...It was like magic." Laura Ingalls Wilder, children's writer In the early nineteenth century, road maintenance was carried out by road gangs, who were often more interested in profit than in keeping roads in good condition. Scot John London McAdam (1756-1836) was a self-taught engineer, who had been appointed trustee of a turnpike. His neighbor suffered rickets and found traveling on potholed roads extremely painful, so McAdam began to experiment with different methods of road construction. Since the days of the Roman Empire, roads had been constructed with a bottom layer of heavy stone, topped by several layers of finer stone and a top layer of gravel. McAdam took this method, but used a compressed heavy roller to compact the layers of rocks together. McAdam's roads had graded layers of broken chippings, with a center higher than more...

A match consists of a wooden or paper stick with a coating of chemicals at one end that ignites when struck against an appropriate surface. The ignition results from thereat generated by friction as the two surfaces are rubbed together. The match enabled people to overcome the limitations of damp tinder and bad weather and create a flame at will, English chemist John Walker (1781-1859) created the first friction match in 1827. He owned a pharmacy in Stockton-on-Tees and manufactured an explosive chemical mixture for use in percussion caps, a component of firearms. He accidentally discovered that this mixture, made of equal quantities of antimony sulfide and potassium chlorate, ignited when rubbed along a rough surface. Walker had previously used chlorate matches, which ignited after being dipped in a bottle of sulfuric acid, but began manufacturing them using the new mixture instead. Walker called the matches "congreves." The chemical composition more...

"The numbers [on the amplifier] all go to eleven.... Well, it's one louder, isn't it? It's not ten." This Is Spinal Tap (1984) A variable resistor—or rheostat—is a device that controls the flow of a current, rheo being Greek for "to flow." Rheostats are employed to adjust the current in electric machines, and to vary the resistance in electric circuits. Examples of their use are the dimming of lights and the controlling of a motor's speed. However, the way that most people encounter variable resistors is behind the knobs on radios or under the sliders on more complicated audio equipment. Turning the volume knob, you are moving the 'finger' of a variable resistor, changing the tapping point and therefore the' resistance, supplying more or less power to the speakers, which makes the sound louder or quieter. The variable resistor's design is based on the Wheatstone Bridge, which was invented by more...

"Do you realize the sound only comes from one person? I've got a way to make it follow the person." Alan Blumlein, electrical engineer For most people, "stereophonic" means listening to audio through a two-channel loudspeaker system. Different elements of the recording can be heard to come from different directions, just as the human ear is naturally able to pinpoint the location of a sound. The man who invented stereophonic sound was an English electrical engineer named Alan Blumlein (1903-1942). While watching one of the early "talkies" in his local cinema in 1931, he became distracted by the disembodied effect of voices coming from a single location when the actors speaking were positioned across the cinema screen. The system he developed to enable the sound to "follow" the voice was called "binaural"—what we now know as stereo. His idea was a simple one. Two microphones were set apart by a more...