Archives November 2014

The Haber process (sometimes called the Haber- Bosch process)—invented by the German chemist Fritz Haber (1868-1934) in 1908—may be the most important technological advance of the twentieth century. At that time, the main way of obtaining large quantities of ammonia was from naturally occurring saltpeter. Ammonia was an incredibly useful substance, with uses ranging from cleaning to fertilizer and explosives. But saltpeter could be difficult to harvest, with deposits occurring on the walls of caves, and making it required the large-scale decomposition of piles of animal dung. In the first decade of the twentieth century, increasing global agriculture was putting a large strain on the supplies of ammonia, and there were fears that the supply would not be able to keep up with the demand. What Haber created was a means of making ammonia that would make it a plentiful resource. He extracted hydrogen gas from methane and made it more...

The development of the firearm magazine was one of many improvements to weapons in the nineteenth century, and its creator's name is still recognized today by gun enthusiasts all over the world. Benjamin Hotchkiss (1826-1885) worked as a gunmaker in Hartford, Connecticut, in the 1850s and 1860s. After the American Civil War the U.S. government had little interest in firearms, and like other famous firearm designers such as John Browning and Hiram Maxim, Hotchkiss moved to Europe to market his designs. He ended up in France in 1867 and set up a factory in St. Denis in 1875—the same year that he designed the bolt-action magazine rifle. The story goes that Hotchkiss was on a train from Vienna to Bucharest when he became engaged in a conversation with a Romanian army officer who suggested the idea that bolt-action rifles needed to be developed further for military use. Hotchkiss took this more...

Transformers convert alternating current (AC) from one voltage to another without changing the frequency. When American William Stanley, Jr. (1858-1916) invented this master of conversion (based on an idea of Lucien Gaulard and John Dixon Gibbs) in 1885, he paved the way for televisions, computers, battery chargers, and lamps. As a result, Stanley was invited to go and work for the entrepreneur George Westinghouse. Transformers take advantage of Michael Faraday's principle of mutual inductance, which enables one coil to induce a current in another coil. The ratio between the input and output currents is determined by the number of loops in the two respective coils. Thus a current can be raised from low voltage to high voltage with relative ease, the significance of which is driven by the fact that a low voltage transmitted over a large distance will dissipate much of its energy, whereas high voltages retain most of more...

“[It will] make it easier and quicker for these Europeans to cut each others' throats." Anonymous acquaintance of Hiram Maxim American inventor Hiram Maxim (1840-1916) would have been much more famous had he won the battle with Thomas Edison over the credit for the invention of the electric light. But his other inventions proved to be just as important, at least in the development of firearms in the late nineteenth century. . Maxim first introduced the principle of his portable, automatic machine gun in an 1883 patent. Several features of Maxim's gun made it innovative. The action was completely automatic and the user needed only to keep his finger pressed on the trigger to fire the gun. The recoil energy of the shot was used to extract the old shell, reload a new one, and automatically fire. The gun had a single barrel that was surrounded by a jacket filled more...

"What is my loftiest ambition? I've always wanted to throw an egg at an electric fan." Oliver Herford, writer, artist, and illustrator Being too hot must have been a major problem for people before the late 1800s. As soon as electrical power was introduced, inventors started to work on ideas for the electric fan. Dr. Schuyler Skaats Wheeler (1860-1923) was the American engineer responsible for creating the personal two-blade desk fan—an invention beloved of anyone who has ever held down an indoor job in the summer months. Invented by Wheeler at the tender age of twenty-two, the fan was made of brass, with no protective caging surrounding the rotating blades, resulting in a product that was both stylish and dangerous in equal measure. However, like most inventions of that time that used electricity, when they were first introduced these fans were the reserve of the rich and the powerful, It more...

It sounds rather like an exercise bicycle from the 1950s but the cyclotron is actually the grandfather of today's most powerful particle accelerators. Having originally studied chemistry, Ernest Lawrence (1901-1958) switched to physics and received his PhD from Yale University in 1925. At this time, scientific insights into the nature of matter were starting to yield interesting results. In Cambridge, England, Ernest Rutherford had been using atomic particles as projectiles with which to bombard atoms. By 1919 he had succeeded in bombarding the nucleus of a nitrogen atom and getting it to absorb a helium nucleus, creating oxygen. This kind of work, however, was reaching a technical limit. The atomic particles from naturally radioactive materials were too few and did not have the energy required to pursue the experiments that Rutherford wanted to perform. In 1927 he issued a plea to physicists to find methods to produce a "copious supply" more...

"... embryonic stem cells were a researcher's dream. Now they're a political hot potato." Frederic Golden, commentator Stem cells are cells that have the ability to differentiate into a diverse range of cell types, creating the potential for the cells to be used to grow replacement tissues. American developmental biologist James Thomson (b. 1958), from the University of Wisconsin School of Medicine, won the race to isolate and culture human embryonic stem cells. On November 6, 1998, the journal Science published the results of Thomson's research, describing how he used embryos from fertility clinics (donated by couples who no-longer needed them), and developed ways to extract stem cells and keep them reproducing indefinitely.  With the ability to develop into any one of the 220 cell types in the body, stem cells hold great promise for treating a host of debilitating illnesses, including diabetes, leukemia, Parkinson's disease, heart disease, and spinal more...

"In 1941 virtually no metallurgist in the U.S. had seen a piece of ductile titanium..." First International Titanium Conference, 1968 Reverend William Gregor discovered titanium as a metal oxide in 1791. Isolating pure titanium proved a herculean task, first done 100 years after its oxide was found. Matthew Hunter of Rensselaer Polytechnic University in the United States accomplished the task, netting miniscule quantities of the metal. Titanium was recognized as strong, light, and resistant to corrosion. The applications for such a metal were nearly infinite, but there was no way to extract large amounts of it. Then, in the early 1930s, metallurgist William Kroll (1889-1973), while working for the German company Siemens & Halske in his native Luxemburg, developed a multi-step process capable to producing the metal in large quantities. The rise of the Nazi party drove Kroll from Luxemburg to the United States, working for the U.S. Bureau of more...

A blink comparator enables astronomers to look at two different photographic plates taken of the same region of the sky on different nights, using the same telescope and plate exposure. If something "blinks" as the view rapidly switches from one illuminated plate to the other, the object has either changed brightness or moved. This apparatus and technique has been used to detect asteroids, comets, and variable stars. Plates taken a few years apart have been used to detect nearby fast-moving stars or to distinguish between binary stars that orbit a common center of mass, and two stars that happen to be close to the same line of sight, or an optical double. The German physicist Carl Pulfrich (1858-1927) developed the device while working for the Carl Zeiss Optical Workshop. Blink comparators were soon being used by observatories around the world and led to the discovery of hundreds of variable stars. more...

Most kinds of mechanical movement in appliances are driven by electric motors—fans, fridges, and even computers are all powered in this way. In 1873 Frenchman Theophile-Zenobe Gramme (1826-1901) was the first to show that electricity could be used to move things efficiently. Semiliterate, and with only a grasp of simple arithmetic, he was not a typical inventor. However, his manual skill and logical thinking led to one of the most important applications of electricity. A carpenter by trade, Gramme was appalled by the dirt produced by newly invented electric batteries and decided to concentrate his efforts on improving their design. It had not been long since Michael Faraday in Britain and Joseph Henry in the United States had created dynamos, which converted energy from movement into electricity. These are the devices that convert leg power to light in bicycle lamps and wind power into electricity. Gramme worked hard and greatly more...


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