Hendrik Antoon Lorentz

Hendrik Antoon Lorentz , 1853-1928, Dutch physicist, a pioneer in formulating the relations between electricity, magnetism, and light. He was one of the first to postulate the existence of electrons. On this he based his explanation of the Zeeman effect (a change in spectrum lines in a magnetic field), for which he shared with Pieter Zeeman the 1902 Nobel Prize in Physics. He extended the hypothesis of G. F. Fitzgerald, an Irish physicist, that the length of a body contracts as its speed increases (see Lorentz contraction ), and he formulated the Lorentz transformation, by which space and time coordinates of one moving system can be correlated with the known space and time coordinates of any other system. This work influenced, and was confirmed by, Einstein's special theory of relativity. Lorentz also discovered (1880), simultaneously with L. V. Lorenz of the Univ. of Copenhagen, the relations (known as Lorentz-Lorenz relations) between the refraction of light and the density of a translucent body. He was professor (1878-1912) at the Univ. of Leiden and director from 1912 of the Teyler laboratory, Haarlem. His works in English include The Theory of Electrons (1909) and Problems of Modern Physics (1927).

Bibliography: See his collected papers (9 vol., 1934-39); study ed. by G. L. de Haas-Lorentz (tr. 1957).

Lorentz, Hendrik Antoon (1853–1928) Dutch physicist and professor at Leiden. His early work concentrated on the theory of electromagnetic radiation devised by James Clerk Maxwell. This led him to the Lorentz transformation and the prediction of the Lorentz-Fitzgerald contraction, both of which helped Einstein to develop his special theory of relativity. Lorentz also worked on the Zeeman effect, for which he and Pieter Zeeman gained the 1902 Nobel Prize in physics.