This Month in Physics History
May 1888: Tesla Patents "Electric Transmission of Power"
Tesla was born in July 1856 in Smiljan, Lika, a region of Croatia, the son of a Serbian Orthodox priest. He studied at the Polytechnic Institute in Graaz, Austria, and the University of Prague, initially intending to specialize in physics and mathematics, against his family's desire that he follow his father in an ecclesiastical career. But he soon became fascinated with electricity, and began his career as an electrical engineer with a Hungarian telephone company in 1881, which is where he first devised the concept of the induction motor.
In February 1882 he discovered the effects of a rotating magnetic field, which has found widespread application in electrical devices that use alternating current.
He spent some time with the Continental Edison Company in Paris designing dynamos, and in 1883 he built a prototype of the induction motor and ran it successfully.
He came to the US the following year and took a job in Thomas Edison's lab, but the two men quickly found themselves at odds over direct current (DC) versus alternating current (AC). Edison espoused DC, which flows continuously in one direction, whereas AC typically changes direction 50 or 60 times per second. With a transformer, the AC voltage can be stepped up, and the current correspondingly stepped down, to minimize resistive heating losses in the transmission lines over long distances. In a DC system, line losses required additional power stations at two-mile intervals.
Tesla developed polyphase alternating current systems of generators, motors and transformers, eventually holding 40 basic US patents. These were bought by George Westinghouse, who was determined to supply America with the Tesla system, which eventually won out as the superior technology and became the standard power in the 20th century.
After receiving a patent on the electric transmission of power in May of 1888, Tesla subsequently demonstrated alternating current electricity at the World Columbian Exposition in Chicago in 1893. He then designed the first hydroelectric powerplant in Niagara Falls in 1895, culminating his lifelong dream.
In 1899 he built an experimental station in Colorado Springs to experiment with high-voltage, high frequency electricity and other phenomena, where he generated and sent out wireless waves without wires for miles. This is also where he made what he regarded as his most important discovery: terrestrial stationary waves. He proved that the Earth could be used as a conductor and would be as responsive as a tuning fork to electrical vibrations of a certain frequency.
Tesla invented the Tesla coil in 1891, which is widely used today in radio and television sets and other electronic equipment. Financially supported by J. Pierpont Morgan, he built the Wardenclyffe laboratory and its famous transmitting tower in Shoreham, Long Island between 1901 and 1905, 187 feet high and capped by a 68-foot dome. It was intended to be the first broadcast system, transmitting both signals and power without wires to any point on the globe. The magnifying transmitter—the largest Tesla coil ever built—was capable of generating 300,000 watts of power and reportedly could produce a bolt of lightning 130 feet long. But Tesla fell out with Morgan before the tower was completed, and the unfinished structure was demolished in 1917.
Among Tesla's other discoveries were the fluorescent light, the bladeless turbine, wireless communications, wireless transmission of electrical energy, and remote control. Yet even today, most history books credit Guglielmo Marconi with invention of the radio, and many electric utilities are still referred to as the "Edison Company", even though they use the Tesla—Westinghouse alternating current system—omissions that have caused some Tesla advocates to dub him the "forgotten father of technology." Tesla himself said of the skeptics of his day, "The present is theirs. The future, for which I really worked, is mine."
For all his (sung and unsung) accomplishments, Tesla was a bona fide eccentric, and his odd habits became more apparent as he aged. He always wore white gloves and rarely shook hands because of progressive germ phobia. He never stayed in a hotel room or floor whose number was divisible by three, feared pearl earrings worn by women, and insisted on large numbers of napkins at meals, which he used to meticulously polish his silverware. At the end of his life he made strange claims about death rays that could make entire armies vanish in seconds and communication with other planets.
He died virtually penniless on January 7, 1943, in the Hotel New Yorker where he lived for the last ten years of his life. Nine months after his death, the US Supreme Patent Court determined that Tesla, not Marconi, should be considered the father of wireless transmission and radio, a somewhat belated` victory for the deceased inventor.
Margaret Cheney, ed. Tesla: Man Out of Time. (Touchstone Books, NY 2001).
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