George FitzGerald (1851-1901), Irish physicist. FitzGerald was educated at Trinity College, Dublin, where he remained as a professor for the rest of his life. Although he did not publish much original work, his influence on 19th-century physics was due to his informal suggestions and dicussions with others, who would try out his ideas. FitzGerald developed the hypothesis that a body moving in an electromagnetic field contracts slightly in the direction of its motion (Lorentz-FitzGerald contraction), an idea which became an important step towards Einstein's theory of relativity.