87th  Top physicists 
Hendrik Antoon Lorentz  



Born  18
July 1853 Arnhem, Netherlands 
Died  4
February 1928 (aged 74) Haarlem, Netherlands 
Nationality  Netherlands 
Fields  Physics 
Alma mater  University of Leiden 
Doctoral advisor  Pieter Rijke 
Doctoral students  Geertruida L. de
HaasLorentz Adriaan Fokker Leonard Ornstein 
Known for  Theory of EM radiation Lorentz force 
Notable awards  Nobel Prize for Physics (1902) 
Hendrik Antoon Lorentz (18 July 1853 – 4 February 1928) was a Dutch physicist who shared the 1902 Nobel Prize in Physics with Pieter Zeeman for the discovery and theoretical explanation of the Zeeman effect. He also derived the transformation equations subsequently used by Albert Einstein to describe space and time.
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Hendrik Lorentz was born in Arnhem, Gelderland (The Netherlands), the son of
Gerrit Frederik Lorentz (1822 – 1893), a welloff nurseryman, and
Geertruida van Ginkel (1826 – 1861). In 1862, after his mother's
death, his father married Luberta Hupkes. From 18661869 he
attended the newly established high school in Arnhem, and in 1870
he passed the exams in classical
languages which were then required for admission to
University.
Lorentz studied physics and
mathematics at the
University of Leiden, where he was strongly
influenced by the teaching of astronomy professor Frederik
Kaiser; it was his influence that led him to become a
physicist. After earning a bachelor's degree, he returned to
Arnhem in 1872 to teach high school classes in mathematics, but he
continued his studies in Leiden next to his teaching position. In 1875
Lorentz earned a doctoral degree under Pieter Rijke on a
thesis entitled "Over de theorie
der terugkaatsing en breking van het licht" (On the
theory of reflection and refraction of light), in which he refined
the electromagnetic theory of James Clerk Maxwell.
In 1881 Hendrik married Aletta Catharina Kaiser, niece of Frederik
Kaiser. She was the daughter of Johann Wilhelm Kaiser, director of
the Amsterdam's
Engraving School and professor of Fine Arts, and designer
of the first Dutch postage stamps (1852). Later Kaiser was
the Director of the National Gallery of Amsterdam. Hendrik and
Aletta's eldest daughter Geertruida Luberta Lorentz
was to become a physicist as well.
In 1878, only 24 years of age, Hendrik Antoon Lorentz was appointed to the newly established chair in theoretical physics at the University of Leiden. On January 25, 1878, he delivered his inaugural lecture on "De moleculaire theoriën in de natuurkunde" (The molecular theories in physics).
During the first twenty years in Leiden, Lorentz was primarily interested in the theory of electromagnetism to explain the relationship of electricity, magnetism, and light. After that, he extended his research to a much wider area while still focusing on theoretical physics. From his publications, it appears that Lorentz made contributions to mechanics, thermodynamics, hydrodynamics, kinetic theories, solid state theory, light, and propagation. His most important contributions were in the area of electromagnetism, the electron theory, and relativity.
Lorentz theorized that the atoms might consist of charged particles and suggested that the oscillations of these charged particles were the source of light. When a colleague and former student of Lorentz, Pieter Zeeman, discovered the Zeeman effect in 1896, Lorentz supplied its theoretical interpretation. The experimental and theoretical work was honored with the Nobel prize in physics in 1902. Lorentz' name is now associated with the LorentzLorenz formula, the Lorentz force, the Lorentzian distribution, and the Lorentz transformation.
In 1895, with the attempt to explain the MichelsonMorley experiment, Lorentz proposed that moving bodies contract in the direction of motion (see length contraction; George FitzGerald had already arrived at this conclusion, see FitzGeraldLorentz Contraction). Lorentz worked on describing electromagnetic phenomena (the propagation of light) in reference frames that moved relative to each other. He discovered that the transition from one to another reference frame could be simplified by using a new time variable which he called local time. The local time depended on the universal time and the location under consideration. Lorentz's publications (of 1895 and 1899) made use of the term local time without giving a detailed interpretation of its physical relevance. In 1900, Henri Poincaré called Lorentz's local time a "wonderful invention" and illustrated it by showing that clocks in moving frames are synchronized by exchanging light signals that are assumed to travel at the same speed against and with the motion of the frame.
In 1899, and again in his paper Electromagnetic phenomena in a system moving with any velocity smaller than that of light (1904), Lorentz added time dilation to his transformations and published what Poincaré in 1905 named Lorentz transformations. It was apparently unknown to Lorentz that Joseph Larmor had used identical transformations to describe orbiting electrons in 1897. Larmor's and Lorentz's equations look somewhat unfamiliar, but they are algebraically equivalent to those presented by Poincaré and Einstein in 1905.^{[1]} Lorentz's 1904 paper includes the covariant formulation of electrodynamics, in which electrodynamic phenomena in different reference frames are described by identical equations with well defined transformation properties. The paper clearly recognizes the significance of this formulation, namely that the outcomes of electrodynamic experiments do not depend on the relative motion of the reference frame. The 1904 paper includes a detailed discussion of the increase of the inertial mass of rapidly moving objects. In 1905, Einstein would use many of the concepts, mathematical tools and results discussed to write his paper entitled "Elektrodynamik" (Electrodynamics) known today as the theory of special relativity. Because Lorentz laid the fundamentals for the work by Einstein, this theory was called the LorentzEinstein theory originally.
The increase of mass was the first prediction of special relativity to be tested, but from early experiments by Kaufmann it appeared that his prediction was wrong; this led Lorentz to the famous remark that he was "at the end of his Latin."^{[2]} The confirmation of his prediction had to wait until 1908. In 1909, Lorentz published "Theory of Electrons" based on a series of lectures in Mathematical Physics he gave at Columbia University.^{[3]}
Poincaré (1902) said of Lorentz's theory of electrodynamics:
Paul Langevin (1911) said of Lorentz:
Lorentz and Emil Wiechert (Göttingen) had an interesting correspondence on the topics of electromagnetism and the theory of relativity, and Lorentz explained his ideas in letters to Wiechert. The correspondence between Lorentz and Wiechert has been published by Wilfried Schröder (Arch. ex. hist. Sci, 1984).
Lorentz was chairman of the first Solvay Conference held in Brussels in the autumn of 1911. Shortly after the conference, Poincaré wrote an essay on quantum physics which gives an indication of Lorentz's status at the time:
Albert Einstein (1953) wrote of Lorentz:
While Lorentz is mostly known for fundamental theoretical work, he also had an interest in practical applications. In the years 19181926, at the request of the Dutch government, Lorentz headed a committee to calculate some of the effects of the proposed Afsluitdijk (Closure Dike) flood control dam on other seaworks in the Netherlands. Hydraulic engineering was mainly an empirical science at that time, but the disturbance of the tidal flow caused by the Afsluitdijk was so unprecedented that the empirical rules could not be trusted. Lorentz proposed to start from the basic hydrodynamic equations of motion and solve the problem numerically. This was feasible for a "human computer", because of the quasionedimensional nature of the water flow in the Waddenzee. The Afsluitdijk was completed in 1933 and the predictions of Lorentz and his committee turned out to be remarkably accurate.^{[5]} One of the two sets of locks in the Afsluitdijk was named after him.
In 1912 Lorentz retired early to become director of research at Teylers Museum in Haarlem, although he remained external professor at Leiden and gave weekly lectures there. Paul Ehrenfest succeeded him in his chair at the University of Leiden, founding the Institute for Theoretical Physics which would become known as the Lorentz Institute. In addition to the Nobel prize, Lorentz received a great many honours for his outstanding work. He was elected a Fellow of the Royal Society in 1905. The Society awarded him their Rumford Medal in 1908 and their Copley Medal in 1918.
Lorentz died in Haarlem, Netherlands. The respect in which he was held in the Netherlands is apparent from O. W. Richardson's description of his funeral:
Richardson describes Lorentz as:
M. J. Klein (1967) wrote of Lorentz's reputation in the 1920s:
There are thirtysix complete papers by Lorentz (mostly in English) that are available for online viewing in the Proceedings of the Royal Netherlands Academy of Arts and Science, Amsterdam.

