Arthur Eddington
Sir Arthur Stanley Eddington ( born December 28, 1882 in Kendal, † November 22, 1944 in Cambridge ) was a British astrophysicist.
Life and work
Eddington was the son of a headmaster, who died when Eddington was two years old. Both parents were Quakers. After the death of his father Eddington moved with his mother and his older sister to Weston -super- Mare, where he went to school. In 1898 he went with a state scholarship to the Owens College, Manchester, and studied physics and mathematics. His teachers included Arthur Schuster and Horace Lamb. He won several awards at the university and received in 1902 a Bachelor of Science with honors. After that he went on a scholarship to Trinity College, Cambridge University, where Edmund Taylor Whittaker, Alfred North Whitehead and Ernest William Barnes were his teachers. In the Tripos examinations in mathematics, he was in 1904 Best (Senior Wrangler ). In 1905 he received his master's degree (MA) and conducted research at the Cavendish Laboratory on thermionic discharge, but soon moved on to mathematics and astronomy research at the Royal Observatory in Greenwich. In 1907 he received the Smith Prize for an essay on proper motion of stars and became a Fellow of Trinity College. In 1913 he was appointed Professor of Astronomy at Cambridge and in the following year director of the observatory at Cambridge, succeeding George Howard Darwin Plumian.
Eddington was one of the first physicists who recognized the significance of Einstein's theory of relativity ( which he learned during the First World War through the mediation of Willem de Sitter 1915 ). He wore about before the meeting of the British Association for the Advancement of Science in 1916 and wrote one of the earliest textbooks about ( Mathematical Theory of Relativity, 1923), which was of great influence in the English-speaking world. In addition, he was instrumental in enforcing the general theory of relativity world: He led the eclipse expedition, which he organized with the Royal Astronomer Frank Watson Dyson, on the volcanic island of Principe in the Gulf of Guinea in West Africa (see figure) on May 29, 1919.
The general theory of relativity postulates that a mass of the size of the sun must be able to bend the space surrounding them clearly. We must look stars, seen from Earth, standing near the sun, a little appear displaced because the light rays would bent by the gravitational field of the sun. To observe this effect, however, one needs a total solar eclipse, since an optical observation of stars in the vicinity of bright sunlight is impossible. Therefore, Eddington traveled to Africa, there to observe the solar eclipse on 29 May 1919. Another team of the expedition watched at the same time the solar eclipse of Sobral (Ceará ) in Brazil. Eddington's observations were hampered by clouds, yet he managed to take pictures. In the following analysis, they were seen by Eddington as confirmation of Einstein's theory. However, later reports came to the conclusion that the former observations were too inaccurate to do so.
Eddington also developed the first true model of the processes occurring in stars processes. Beginning of the 20th century, astronomers were indeed quite sure that stars are made of gas. However, it could not explain why the resulting mass by their great pressure from outside the star can not collapse inwardly. Eddington introduced the now accepted theory on that, although with increasing depth increase pressure and temperature in the star, but the interplay of gravitational and radiation pressure can prevent a collapse of the star. He wrote about the time of his authoritative textbook The Internal Constitution of Stars (1926 ), in which he also introduced the mass - luminosity relation.
The Eddington limit, which describes the maximum luminosity that can have a star in hydrostatic equilibrium, is named after him.
Eddington had in the 1930s, a confrontation with the young Subrahmanyan Chandrasekhar over its limit for the mass of white dwarfs. He leaned his theories categorically and used his influence here as the most famous astrophysicist of the time. The unequal contest was crucial that Chandrasekhar moved to the U.S..
In addition to its astrophysical works avowed Quakers also wrote a number of philosophical treatises. Towards the end of his career his interest in numerical relations of fundamental constants, however, came to rejection and even earned him the ridicule by colleagues. He tried to find a synthesis of the theory of relativity and quantum mechanics, which also found no response in the physics community.
Works
- Stellar Movements and the Structure of the Universe, London: Macmillan 1914
- Report on the relativity theory of gravitation. London, Fleetway press, Ltd.. , 1918, 2nd edition 1920, Dover reprint 2006
- Space, Time and Gravitation: An Outline of the General Relativity Theory. Cambridge University Press, 1920, 1987 German translation: space, time and gravity. An outline of the general relativity theory, Vieweg 1923
- German Translation: Theory of Relativity in mathematical treatment, Springer Verlag 1925 ( translator Alexander Ostrowski )
- German translation: Stars and Atoms, Vandenhoeck and Ruprecht, 4th Edition 1958
- German translation: The world of physics, and a trial of its philosophical interpretation, Vieweg 1931
- German translation: science on new cars, Vieweg 1935 (translator Wilhelm Westphal )
Awards
In 1930 he was knighted, and in 1938 he received the Order of Merit. He was a member of the Royal Society of Edinburgh, the Royal Irish Academy, the Russian Academy of Sciences, the Berlin Academy of Sciences and the National Academy of Sciences. In 1926 he held the Bakerian Lecture ( Diffuse matter in interstellar space).
An asteroid and a lunar crater named after him. The Eddington Medal of the Royal Astronomical Society bears his name.