Difference between revisions of "George FitzGerald" - New World Encyclopedia
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<<'''This article is too short. Please expand it and divide it into sections. Add a section on Legacy.'''>> | <<'''This article is too short. Please expand it and divide it into sections. Add a section on Legacy.'''>> | ||
| − | '''George Francis FitzGerald''' (3 August 1851 – 22 February 1901) | + | '''George Francis FitzGerald''' (3 August 1851 – 22 February 1901) postulated a forshortening of geometry in the direction of motion that became known as the Lorentz-FitzGerald contraction. He was also the first to suggest equipment and methods capable of generating electromagnetic waves. He suggested that the speed of light is the maximum that can be achieved, 15 years before Einstein made a similar postulate the basis for his theory of relativity. |
| − | FitzGerald was born at No 19 Lower Mount Street in [[Dublin]] on August 3, 1851 to the Reverend William FitzGerald and his wife Anne Francis Stoney. Rev. FitzGerald was professor of moral philosophy in Trinity and vicar of St Anne's, Dawson Street at the time of his son's birth. He was consecrated Bishop of Cork in 1857 and translated to [[Diocese of Killaloe|Killaloe]] in 1862. FitzGerald's mother was the sister of George Johnstone Stoney, who in the | + | ==Biography== |
| + | ===Early years=== | ||
| + | FitzGerald was born at No 19 Lower Mount Street in [[Dublin]] on August 3, 1851 to the Reverend William FitzGerald and his wife Anne Francis Stoney. Rev. FitzGerald was professor of moral philosophy in Trinity and vicar of St Anne's, Dawson Street at the time of his son's birth. He was consecrated Bishop of Cork in 1857 and translated to [[Diocese of Killaloe|Killaloe]] in 1862. FitzGerald's mother was the sister of George Johnstone Stoney, who in the 1870s estimated the charge of an elementary particle of electricity, calling it "the electron." Naturally, Stoney exerted an important formative influence on FitzGerald's life. | ||
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| + | FitzGerald and two of his brothers, William and Maurice, were educated by tutors in their youth. When he was 16, FitzGerald entered Trinity College in Dublin. He was proficient not only in technical subjects, but also in the field of sports in which he was an active participant. FitzGerald graduated at the top of his class in mathematics and science in 1871, and set on a program of reading to compete for a fellowship at Trinity, during which time he familiarized himself with the works of Joseph Louis Lagrange, Pierre-Simon Laplace, and Nicholas Poisson. He secured the fellowship he had sought in 1877, and began tutoring at Trinity. In 1881, he was elevated to Erasmus Smith Professor of Natural and Experimental Philosophy, a position that he held until his death. | ||
Fitzgerald published his first paper in 1876 on an explanation of the changes in the plane of polarization of light by a magnet, using Maxwell's equations and the theories of James MacCullagh, who had applied the principle of least action to the theory of light. He became a Fellow of Trinity in 1877 and spent the rest of his career at the College. | Fitzgerald published his first paper in 1876 on an explanation of the changes in the plane of polarization of light by a magnet, using Maxwell's equations and the theories of James MacCullagh, who had applied the principle of least action to the theory of light. He became a Fellow of Trinity in 1877 and spent the rest of his career at the College. | ||
Revision as of 12:18, 17 August 2007
<<This article is too short. Please expand it and divide it into sections. Add a section on Legacy.>>
George Francis FitzGerald (3 August 1851 – 22 February 1901) postulated a forshortening of geometry in the direction of motion that became known as the Lorentz-FitzGerald contraction. He was also the first to suggest equipment and methods capable of generating electromagnetic waves. He suggested that the speed of light is the maximum that can be achieved, 15 years before Einstein made a similar postulate the basis for his theory of relativity.
Biography
Early years
FitzGerald was born at No 19 Lower Mount Street in Dublin on August 3, 1851 to the Reverend William FitzGerald and his wife Anne Francis Stoney. Rev. FitzGerald was professor of moral philosophy in Trinity and vicar of St Anne's, Dawson Street at the time of his son's birth. He was consecrated Bishop of Cork in 1857 and translated to Killaloe in 1862. FitzGerald's mother was the sister of George Johnstone Stoney, who in the 1870s estimated the charge of an elementary particle of electricity, calling it "the electron." Naturally, Stoney exerted an important formative influence on FitzGerald's life.
FitzGerald and two of his brothers, William and Maurice, were educated by tutors in their youth. When he was 16, FitzGerald entered Trinity College in Dublin. He was proficient not only in technical subjects, but also in the field of sports in which he was an active participant. FitzGerald graduated at the top of his class in mathematics and science in 1871, and set on a program of reading to compete for a fellowship at Trinity, during which time he familiarized himself with the works of Joseph Louis Lagrange, Pierre-Simon Laplace, and Nicholas Poisson. He secured the fellowship he had sought in 1877, and began tutoring at Trinity. In 1881, he was elevated to Erasmus Smith Professor of Natural and Experimental Philosophy, a position that he held until his death.
Fitzgerald published his first paper in 1876 on an explanation of the changes in the plane of polarization of light by a magnet, using Maxwell's equations and the theories of James MacCullagh, who had applied the principle of least action to the theory of light. He became a Fellow of Trinity in 1877 and spent the rest of his career at the College.
In 1878, Fitzgerald expanded on his ideas, submitting a paper, which he admitted was loosly put together, and which was reviewed by Maxwell. It was to have explained optical properties of light in terms of Maxwell's electromagnetic theory. Maxwell's remarks on the paper were only forwarded to Fitzgerald in November of 1879, a few days after Maxwell's death.
In 1879 and 1880, he presented papers concluding that electromagnetic waves could not be produced electrically, although it had been long recognized that visible light was just such a form of radiation.
One of the effects of Fitzgerald's research was to demonstrate that Maxwell's theory could not be interpreted as a deformation of a material medium of any kind, a view that two other important contributors to the field, George Gabriel Stokes and William Thomson, still clung to. Fitzgerald's work was later credited with having paved the way for an explanation of various optical and electrical phenomena that would require an understanding of the electron to fully appreciate.
In 1878, Fitzgerald met the physicst Oliver Lodge, and the two exchanged ideas and correspondence. It appears that Fitzgerald discouraged Lodge from pursuing a means of producing electromagnetic waves predicted by Maxwell's theory. Soon reversing this viewpoint, however, Fitzgerald tackled the subject again and produced papers in the early 1880s that gave expressions for the energy of an electromagnetic wave.
But Fitzgerald's viewpoint changed when he realized that "action at a distance" theories were not completely equivalent to Maxwell's equations, as they did not include a "displacement current" that Maxwell said would exist even in a vacuum. In 1883, he proposed testing Maxwell's theories by looking for electromagnetic waves that could be produced through an oscillating circuit. He suggested in the same year that such oscillations could be produced by the discharge of a "capacitor," a device that consists of two conducting plates separated by an insulator and that is capable of storing an electric charge.
Along with Oliver Lodge, Oliver Heaviside, and Heinrich Hertz, FitzGerald was a leading figure among the group of 'Maxwellians" who revised, extended, clarified, and confirmed James Clerk Maxwell's theory of the electromagnetic field in the late 1870s and 1880s.
In 1883, following from Maxwell's equations, he suggested a device for producing rapidly oscillating electric current, to generate electromagnetic waves, a phenomenon first shown experimentally by Heinrich Hertz.
However, he is better known for his conjecture in 1889 that if all moving objects were foreshortened in the direction of their motion, it would account for the curious result of the Michelson-Morley experiment. FitzGerald based this idea in part on the way electromagnetic forces were known to be affected by motion; in particular, he drew on equations that had been derived a short time before by his friend Oliver Heaviside. The Dutch physicist Hendrik Lorentz hit on a very similar idea in 1892 and developed it more fully in connection with his theory of electrons. The so-called FitzGerald-Lorentz contraction or Lorentz-FitzGerald contraction hypothesis later became an important part of Albert Einstein's special theory of relativity, published in 1905.
Long a sufferer from digestive problems, George Francis FitzGerald succumbed to a perforated ulcer at home on 22 February 1901.
FitzGerald was the nephew of George Johnstone Stoney, the Irish physicist who invented the term "electron."
See also
ReferencesISBN links support NWE through referral fees
- G.F. Fitzgerald, The ether and the earth's atmosphere, Science 13, 390 (1889).
- Sarkar, Tapan. 2006. History of wireless. Wiley series in microwave and optical engineering. Hoboken, N.J.: Wiley-Interscience. ISBN 0471783013.
External links
- John J. O'Connor and Edmund F. Robertson. George FitzGerald at the MacTutor archive
- Millenium Trinity Monday Memorial Discourse by Professor J. M. D. Coey
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