Archives November 2013

An early incandescent light bulb with the coils giving electrical contact to the filament inside the glass. Decades before Thomas Edison filed a patent for his electric lamp, Scotsman James Bowman Lindsay (1799-1862) produced constant electric light in what became a prototype of the modern light bulb. Building on Humphry Davy's successful yet impractical platinum incandescent light, which he developed in 1802, Lindsay managed to create a more usable form of the light bulb. Having secured a position as a lecturer at the Watt Institution in Dundee, Scotland, in 1829, Lindsay began experimenting with constant electric light. He demonstrated his invention in 1835 at a public meeting in Dundee. The light from an incandescent bulb is produced from a filament through which an electrical current is passed. Lindsay claimed that, with his light, he could "read a book at a distance of one and a half foot." This was an more...

"The English are fools... they give their children the smallpox to prevent their catching it." Voltaire, Letters on the English (c. 1778) Smallpox is believed to have first appeared around 10,000 B.C.E. Ramses V died suddenly in 1157 B.C.E.; his mummy bears scars that have a striking resemblance to those left by that scourge. Smallpox killed about a third of its victims and left many survivors scarred. But it was noted that survivors never got smallpox again. After the eldest son of China's Prime Minister Wang Dan died around 1000 B.C.E. of smallpox, Wang Dan sought a cure for it. A Daoist monk introduced the technique of variolation, a type of inoculation. Scab- coated pustules taken from survivors were ground up and blown into the nose like snuff. Reports of inoculation reached Europe in the 1700s. In London, in 1721, Lady Wortley Montague and the Princess of Wales urged that more...

“... an alien race that looked like insects... would build robots to look like themselves.. " Kevin J. Anderson Before the Waseda-Hitachi Leg II (WHL-11) biped robot was unveiled at the 1985 Tsukuba Expo in Japan, robots could roll, drag, or crawl their way around. But here was a real breakthrough. This one could walk. Developed by Hitachi in collaboration with Waseda University, Japan, and with an onboard computer and hydraulic pump, the WHL-11 was capable of static walking on a flat surface at around thirteen seconds per step. The robot was also able to turn. If a robot could walk like a human, it had been reasoned, it would be able to maneuver around objects and go up and down stairs—the applications of such a machine would be almost limitless. To do so, however, it had to have two legs, just like a person. It would also need to more...

"The privilege of making stockings for everyone is too important to grant to any individual." Queen Elizabeth I to William Lee William Lee (circa 1550-1610), a clergyman from Nottinghamshire, England, invented the stocking frame in 1589. One story suggests that he invented it to relieve his mother and sisters of the burden of knitting; another has it that a girl was showing more interest in her knitting than in him. Knitted fabrics are constructed by the interlocking of a series of loops, with each row of loops caught into the previous row. The stocking frame allowed production of a complete row of loops, held by a long bar similar to a knitting needle; a second bar opposed it, and each loop, picked up by a piece of wire, was transferred to the first bar. Lee's first machine, which produced coarse wool stockings, was refused a patent by Queen Elizabeth I. more...

"The only type of operation that could ever be universal would be an arthroplasty." John Charnley, lecture in 1959 More than 800,000 hip replacement operations are carried out globally every year. These enable their recipients to live more mobile and pain-free lives after their worn out, damaged, or diseased hip joints are replaced with artificial prostheses. It was the pioneering work of English surgeon John Charnley (1911-1982) that led to low-friction arthroplasty becoming the gold-standard procedure for hip replacement. Charnley moved from a method of compression fixation of fractures to considering actually replacing the joint during his investigations into the. best way to treat osteoarthritis and other conditions limiting hip movement. In a lecture to the East Denbigh and Flint division of the British Medical Association in 1959, he said, "In orthopedics, surgeons yearn for an easy hip operation, or, if a good operation is difficult,...[that] it should be universally more...

"The depth charge was such a successful device that it attracted the attention of the United States..." Chris Henry, Museum of Naval Fire Power The first significant use of submarines in warfare occurred during World War I, and with that came the need for anti-submarine weapons. The idea of using the destructive shockwaves of a "dropping mine" against submarines was discussed by the British Navy in 1910. However, it was not until the Commander in Chief, Sir George Callaghan (1852-1920), requested their production in 1914thatthey became a reality. It is the "D" type, developed by Herbert Taylor in 1915 at HMS Vernon Torpedo and Mine School, Portsmouth, England, that is credited with being the first effective depth charge. This was essentially a steel barrel packed with high explosive that could be detonated at preselected depths. Early depth charges were deployed simply by rolling them off racks on the stern of more...

"Nature composes some of her loveliest poems for the microscope and the telescope." Theodore Roszak, academic and historian The earliest microscope was no more than a single small lens that magnified between six and ten times. Sacharias Jansen and his father, Hans, a lens maker, experimented with combinations of lenses and realized that greater magnification could be obtained by an inversion of the telescope. Their compound microscope combined a magnifying objective lens (the one closest to the object being investigated) with an eye lens at the opposite end of a tube. A focusing device was added by the Italian Galileo Galilei. The circulation of blood through capillaries was observed by the Italian physiologist Marcello Malpighi (1624-1694). The popularity of microscopes was greatly enhanced by the publication of Micrographia (1655) by English scientist Robert Hooke. The Dutchman Anthoni van Leeuwenhoek (1632-1723) used a microscope to count the number of threads in more...

Dams are built for a number of purposes: to generate hydroelectric power; control flooding; safeguard water supplies for irrigation, domestic, or industrial use; provide for recreation; or ease navigation. The earliest known dam was built by the Egyptians across the Garawi Valley in 2800 B.C.E. and measured 370 feet (113 m) along its crest. The masonry shell was filled with earth and rubble, but as it was not sealed against water, the center of the dam was soon washed away. This failure discouraged the Egyptians from further forays into dam construction. The Romans, armed with their knowledge of concrete, were more successful. Their constructions initially relied on sheer weight of material to resist the water, but in the first century they built the first arch- type dam at Glanum in France. The apex of the arch pointed upstream, transferring the force along the dam and into the solid bedrock of more...

"Crystals grew inside rock like arithmetic flowers... obedience to an absolute geometry." Anne Dillard, American author Crystals are solids—like salt, diamond, and quartz— that have their constituent atoms (or molecules) in regular orders. These patterns repeat in all directions. X-rays penetrate solids and are scattered by the clouds of electrons that surround the nuclei of each atom. Because the atomic arrays in crystals are strictly regular, the X-ray scattering is not random. Measuring the intensity of the X-rays in different' directions and the specific angles at which...the scattering occurs enables the separation of the arrays of crystal atoms to be calculated. The study of crystal atom spacing and ordering is known as crystallography. X-rays have wavelengths that are of the same order of magnitude as both the sizes of typical atoms, and also the spacing between solid arrays of atoms. In 1912 Max von Laue (1879-1960) and Paul Ewald (1888-1985) more...

"My notion of a wife at 40 is that a man should be able to change her, like a banknote, for two 20s." When Marco Polo traveled to China in the late thirteenth century he was astonished to see the locals use paper money instead of coins. Prompted by a copper shortage, the Tang Dynasty (618-907) introduced this new monetary system in 806, more than 800 years before the first European banknotes. While commodity money (the trading of goods that have an intrinsic value, such as gold and cattle) has been around since the dawn of civilization, the first standardized coinage is thought to have appeared in Lydia (western Asia Minor) in the seventh century B.C.E. This was the first time that the nominal value of money was higher than the worth of its inherent material. Ancient Greek historian Herodotus criticized the "gross commercialism" that this system induced. Swedish bank more...