Fitzgerald, George Francis (1851–1901)

Irish physicist known for his work on electromagnetics. He was the first to suggest a method of propagating radio waves, which helped towards the development of wireless telegraphy. In 1892 he explained the anomalous results of the Michelson–Morley experiment in 1887 by supposing that bodies moving through the ether contracted as their velocity increased. The effect, since known as the Fitzgerald–Lorentz contraction, was developed by Albert Einstein's special theory of relativity.

Fitzgerald was born in Dublin and studied there at Trinity College, where he was professor of natural and experimental philosophy from 1888.

He predicted that a rapidly oscillating (that is, alternating) electric current should result in the radiation of electromagnetic waves – a prediction proved correct in the late 1880s by Heinrich Hertz's early experiments with radio, which Fitzgerald brought to the attention of the scientific community in Britain.

Considering the Michelson–Morley result – or lack of result – Fitzgerald worked out a simple mathematical relationship to show how velocity affects physical dimensions. The idea was independently arrived at and developed by Dutch physicist Hendrik Lorentz in 1895. In 1905 the contraction hypothesis was incorporated and given a different interpretation in Albert Einstein's theories of relativity.