Hendrik Lorentz

Hendrik Antoon Lorentz was born on 18 July 1853 in Arnhem, Netherlands, the son of Gerrit Frederik Lorentz (1822–1893) and Geertruida van Ginkel (1826–1861). In 1862, after his mother's death, his father married Luberta Hupkes. Despite being raised as a Protestant, he was a freethinker in religious matters and regularly attended Catholic mass at his local French church. From 1866 to 1869, Lorentz attended the Hogere Burgerschool in Arnhem, a new type of public high school recently established by Johan Thorbecke. His results in school were exemplary; not only did he excel in the physical sciences and mathematics, but also in English, French, and German. In 1870, he passed the exams in classical languages, which were then required for admission to university. In 1870, Lorentz entered Leiden University, where he was strongly influenced by the teaching of astronomy professor Frederik Kaiser; it was his influence that led Lorentz to become a physicist. The following year, he obtained a B.Sc. in Mathematics and Physics. In 1872, he returned to Arnhem to become a night school teacher, while also continuing his studies at Leiden. In 1875, he received his Ph.D. under Pieter Rijke with a thesis on the reflection and refraction of light, in which he refined the electromagnetic theory of James Clerk Maxwell. == Career ==

In 1878, Lorentz was appointed to the newly established Chair of Theoretical Physics at Leiden University; the position had initially been offered to Johannes van der Waals, but he had just accepted a professorship at the University of Amsterdam. On 25 January 1878, he delivered his inaugural lecture titled De moleculaire theoriën in de natuurkunde (The molecular theories in physics). During his first 20 years at Leiden, Lorentz was primarily interested in the electromagnetic theory of electricity, magnetism, and light. After that, he extended his research to a much wider area while still focusing on theoretical physics. He made significant contributions to fields ranging from hydrodynamics to general relativity. His most important contributions were in the area of electromagnetism, the electron theory, and relativity. In 1910, Lorentz decided to reorganize his career; his teaching and management duties at Leiden University were taking up too much of his time, leaving him little time for research. He initially asked Albert Einstein to succeed him as Professor of Theoretical Physics at Leiden. However, Einstein did not accept, because he had just taken up a position at ETH Zurich and the prospect of having to fill Lorentz's shoes made him shiver. He ultimately chose Paul Ehrenfest as his successor. In 1912, Lorentz resigned from his chair at Leiden University to become Curator of the Physical Cabinet at Teylers Museum in Haarlem. He continued to teach at Leiden as Extraordinary Professor, delivering his famous "Monday morning lectures" on new developments in theoretical physics. == Research ==

Electrodynamics and relativity In 1892 and 1895, Lorentz worked on describing electromagnetic phenomena (the propagation of light) in reference frames that move relative to the postulated luminiferous aether. He discovered that the transition from one to another reference frame could be simplified by using a new time variable that he called local time and which depended on universal time and the location under consideration. Although he did not give a detailed interpretation of the physical significance of local time, with it, he could explain the aberration of light and the result of the Fizeau experiment. In 1900 and 1904, Henri Poincaré called local time Lorentz's "most ingenious idea" 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 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 dissimilar, but they are algebraically equivalent to those presented by Poincaré and Einstein in 1905. known today as the special theory of relativity. Einstein's unique perspective on the topic was not widely understood initially, causing some physicists to confusingly refer to the theory as the Lorentz–Einstein theory. In 1910, Lorentz's 1906 lectures at Columbia University, were published under the title The Theory of Electrons. Lorentz covered his entire theory of the electron, including his work and that of Einstein on relativity. In this work he spoke affirmatively of Einstein's theory: General relativity Lorentz was one of few scientists who supported Einstein's search for general relativity from the beginning – he wrote several research papers and discussed with Einstein personally and by letter. For instance, he attempted to combine Einstein's formalism with Hamilton's principle (1915), and to reformulate it in a coordinate-free way (1916). Lorentz wrote in 1919: Quantum mechanics Lorentz gave a series of lectures in the fall of 1926 at Cornell University on the new quantum mechanics; in these he presented Erwin Schrödinger's wave mechanics. == Civil work ==

After World War I, Lorentz was one of the driving forces behind the founding of the Wetenschappelijke Commissie van Advies en Onderzoek in het Belang van Volkswelvaart en Weerbaarheid, a committee which was to harness the scientific potential united in the Royal Netherlands Academy of Arts and Sciences (KNAW) for solving civil problems such as food shortage which had resulted from the war. Lorentz was appointed chair of the committee. However, despite the best efforts of many of the participants the committee would harvest little success. The only exception being that it ultimately resulted in the founding of TNO, the Netherlands Organisation for Applied Scientific Research. 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 quasi-one-dimensional nature of the water flow in the . The Afsluitdijk was completed in 1932, and the predictions of Lorentz and his committee turned out to be remarkably accurate. One of the two sets of locks in the Afsluitdijk was named after him. == Family ==

In 1881, Lorentz married Aletta Catharina Kaiser, with whom he had two daughters and one son. The eldest daughter, Geertruida, was a physicist and a doctoral student of her father. She married Wander de Haas, who was the Director of the Kamerlingh Onnes Laboratory at Leiden University. == Death and funeral ==

, February 1928. In January 1928, Lorentz became seriously ill, and died shortly after on 4 February. Amongst others, the funeral was attended by Albert Einstein and Marie Curie. == Recognition ==

Memberships Awards Orders == Tributes ==

According to his biography published by the Nobel Foundation, "It may well be said that Lorentz was regarded by all theoretical physicists as the world's leading spirit, who completed what was left unfinished by his predecessors and prepared the ground for the fruitful reception of the new ideas based on the quantum theory." Paul Langevin (1911) said of Lorentz: == See also ==

• Many papers by Lorentz (mostly in English) are available for online viewing in the Proceedings of the Royal Netherlands Academy of Arts and Science, Amsterdam. • • , (Vol. I online) • • {{Cite book|author=Lorentz, Hendrik Antoon • English Wikisource translation: The Principle of Relativity and its Application to some Special Physical Phenomena • {{Citation • {{Cite book == Notes ==