A D V E N T U R E S in C Y B E R S O U N DArthur Edwin Kennelly : 1861-1949
1902, the American electrical engineer Arthur Edwin Kennelly and the British physicist and electrician Oliver Heaviside (1850-1925) independently and almost simultaneously announce the probable existence of a layer of ionised gas, high in the atmosphere, that affects the propogation of radio waves and enables them to follow the curvature of the earth.
In 1902, the American electrical engineer Arthur Edwin Kennelly and the British physicist and electrician Oliver Heaviside, independently and almost simultaneously, announced the probable existence of a layer of ionized gas high in the atmosphere that affects the propagation of radio waves. This layer, formerly called the Heaviside or Kennelly-Heaviside layer, is one of several layers in the ionosphere. Although the ionosphere is transparent to the shortest radio waves, it bends or reflects the longer waves. Because of its reflection, radio waves can be propagated far beyond the horizon. Propagation of radio waves in the ionosphere is stongly affected by time of day, season, and sunspot activity. Slight variations in the nature and altitude of the ionosphere, which can occur rapidly, can affect the quality of the long distance reception. The ionosphere is also responsible for Skip, the reception at a considerable distance of a signal that cannot be received at a closer point. This phenomenon occurs when the ground ray has been absorbed by the intervening ground and the ionospherical propagated ray is not reflected at an angle sufficiently steep to be received at short distances from the antenna.
Arthur Edwin Kennelly (b. Dec. 17, 1861, Colaba, India--d. June 18, 1939, Boston), U.S. electrical engineer who made innovations in analytic methods in electronics, particularly the definitive application of complex-number theory to alternating-current (ac) circuits. After working as an office boy for a London engineering society, as an electrician, and on a cable-engineering ship, in 1887 Kennelly joined Thomas Edison's staff at West Orange, N.J., where he was chief assistant until 1894. Then, with Edwin J. Houston, he formed the consulting firm of Houston and Kennelly in Philadelphia. The mathematical analysis of direct-current circuits was a simple matter, but the analysis of ac circuits was more complicated. The publication of Kennelly's paper "Impedance" immediately allowed engineers to begin applying complex-number techniques to ac theory. Kennelly noticed that Guglielmo Marconi's reception, in Newfoundland in 1901, of radio signals transmitted from England was received far better than was predicted by radio-wave theory. The following year he postulated that the radio waves were being reflected back to Earth from an ionized layer in the upper atmosphere. Shortly thereafter the British physicist Oliver Heaviside independently propounded the same theory, and the layer thus became known as the Kennelly-Heaviside layer (now called the E region of the ionosphere).
Kennelly was born in Bombay on Dec 17, 1861 and died on June 18, 1939 in Boston Massachusetts. He left Edison in 1894 and was appointed Professor of Electrical Engineering at Harvard in 1902. In 1902 he showed that an electrically conducting stratum must exist because of rarefaction of the atmosphere at a height of about fifty miles with conductivity several times as great as that of sea water. Kennelly in the USA and Heaviside in Britain were recognised as co-discoverers of the radio mirror or roof, hence the [term] the Kennelly Heaviside Layer. From 1913-24 he was Professor of Electrical Engineering at MIT (Massachusetts Institute of Technology) and in 1916 became President of the IRE (Institute of Radio Engineers). Kennelly received the Edison Gold Medal of the AIEE (American Institute of Electrical Engineers) in 1933. A quote from him in 1926....
"through radio I look forward to a united states of the world. Radio is standardising the peoples of the earth, English will become the universal language because it is predominantly the language of the ether. The most important aspect of radio is its sociological influence" Source: Loren Haroldson, Ellendale, MN, 56026, USA
KENNELLY, Arthur Edwin. British-American electrical engineer. Born: Bombay, India, December 17, 1861, Died: Boston, Massachusetts, June 18, 1939. Prominent contributor to the science of electrical engineering. Kennelly was an electrical engineer who made innovations in analytic methods in electronics, particularly the definitive application of complex-number theory to alternating-current (ac) circuits. As a youngster Kennelly grew interested in the expanding field of electricity and became a telegraph operator in his teens, as Edison had been a couple of decades before. After working as an office boy for a London engineering society, as an electrician, and on a cable-engineering ship, in 1887 Kennelly, age 26, joined Thomas Edison's staff at West Orange, N.J., where he was chief assistant until 1894. Between 1894 to 1901, he worked as a consulting engineer with the Edison General Electric Company, the General Electric Company of New York. Then, with Edwin J. Houston, he formed the consulting firm of Houston and Kennelly in Philadelphia, thus going into business for himself. He was affiliated with Harvard from 1902 until 1930 as well as the Massachusetts Institute of Technology (Professor of Electrical Engineering) from 1913 until 1930. In 1916 Kennelly became President of the IRE (Institute of Radio Engineers). Kennelly received the Edison Gold Medal of the AIEE (American Institute of Electrical Engineers) in 1933. {The IRE and the AIEE later combined into today's IEEE.} Like Heaviside and Steinmetz, his importance to the development of electricity was not so much in the construction of novel devices making use of electrical circuits, as in the application of advanced mathematics to the understanding of the behavior of such circuits. The mathematical analysis of direct-current circuits was a simple matter, but the analysis of ac circuits was more complicated. The publication of Kennelly's paper "Impedance" immediately allowed engineers to begin applying complex-number techniques to ac theory. He is best known, however, for a suggestion he made in 1902 arising out of the fact that the wireless messages of Marconi had reached from England to Newfoundland, working their way around the bulge of the earth. The radio waves ought to have moved in a straight line, as light waves do, and have been unable to travel past the horizon. That radio waves did travel beyond the horizon made it seem to Kennelly that somewhere in the upper atmosphere was a layer of electrically charged particles which, his theories told him, could reflect radio waves. Thus, Marconi's message crossed the Atlantic Ocean by bouncing off the upper atmosphere. The following year he postulated that the radio waves were being reflected back to Earth from an ionized layer in the upper atmosphere. This speculation, a more sophisticated version of something Stewart had suggested twenty years earlier, was independently published some months later by the British physicist Oliver Heaviside and was eventually shown to be founded in fact by Appleton. The layer thus became known as the Kennelly-Heaviside layer (now called the E region of the ionosphere). The discovery explains Marconi's success in making radio contact over the curved surface of the earth; it is the upper ionized layer of the atmosphere that reflects radio waves. Signals are clearer at night because of this. The Kennelly-Heaviside layer layer is one of several layers in the ionosphere. Although the ionosphere is transparent to the shortest radio waves, it bends or reflects the longer waves. Because of its reflection, radio waves can be propagated far beyond the horizon. Propagation of radio waves in the ionosphere is stongly affected by time of day, season, and sunspot activity. Slight variations in the nature and altitude of the ionosphere, which can occur rapidly, can affect the quality of the long distance reception. The ionosphere is also responsible for Skip, the reception at a considerable distance of a signal that cannot be received at a closer point. This phenomenon occurs when the ground ray has been absorbed by the intervening ground and the ionospherical propagated ray is not reflected at an angle sufficiently steep to be received at short distances from the antenna. Ellis E. Youngblood
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