George FitzGerald

For other people named George FitzGerald, see George FitzGerald (disambiguation).

George Francis FitzGerald
George Francis FitzGerald
Born	3 August 1851 Dublin
Died	22 February 1901 Dublin
Residence	Dublin
Citizenship	British
Nationality	Irish
Fields	physics
Institutions	Trinity College Dublin
Alma mater	Trinity College Dublin

George Francis FitzGerald (3 August 1851 – 22 February 1901) was an Irish professor of "natural and experimental philosophy" (i.e., physics) at Trinity College in Dublin, Ireland, during the last quarter of the 19th century.

His Life and His Work in Physics

FitzGerald was born at No. 19, Lower Mount Street in Dublin on 3 August 1851 to the Reverend William FitzGerald and his wife Anne Francis Stoney. Professor of Moral Philosophy in Trinity and vicar of St Anne's, Dawson Street, at the time of his son's birth, William FitzGerald was consecrated Bishop of Cork, Cloyne and Ross in 1857 and translated to Killaloe and Clonfert in 1862. George returned to Dublin and entered Trinity as a student at the age of 16. He became a Fellow of Trinity in 1877 and spent the rest of his career at this college.

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 mathematical theories of the electromagnetic field during the late 1870s and the 1880s.

In 1883, following from Maxwell's equations, FitzGerald suggested a device for producing rapidly oscillating electric currents to generate electromagnetic waves, a phenomenon which was first shown to exist experimentally by the German physicist Heinrich Hertz in 1888.

FitzGerald suffered from many digestive problems for much of his shortened life. He became very ill with stomach problems and died after an operation on a perforated ulcer at his home in Dublin on 21 February 1901.

FitzGerald was also the nephew of George Johnstone Stoney, the Irish physicist who coined the term "electron". After the particles were discovered by J. J. Thomson and Walter Kaufmann in 1896, FitzGerald was the one to propose calling them electrons.

Plaque at 7 Ely Place, Dublin, where Fitzgerald lived

Length contraction

FitzGerald is better known for his conjecture in his short paper "The Ether and the Earth's Atmosphere" (1889) that if all moving objects were foreshortened in the direction of their motion, it would account for the curious null-results 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, FitzGerald used some equations that had been derived a short time before by his friend the electrical engineer Oliver Heaviside. The Dutch physicist Hendrik Lorentz hit on a very similar idea in 1892 and developed it more fully into Lorentz transformations, in connection with his theory of electrons.

The FitzGerald-Lorentz contraction (or Lorentz-FitzGerald contraction hypothesis) became an essential part of the Special Theory of Relativity, as Albert Einstein published it in 1905. He demonstrated the kinematic nature of this effect, by deriving it from the principle of relativity and the constancy of the speed of light.

External links

• O'Connor, John J.; Robertson, Edmund F., "George FitzGerald", MacTutor History of Mathematics archive, University of St Andrews, http://www-history.mcs.st-andrews.ac.uk/Biographies/FitzGerald.html .
• Millenium Trinity Monday Memorial Discourse by Professor J. M. D. Coey
• FitzGerald letters at the Royal Dublin Society, with digitized images of over 2000 letters to and from FitzGerald