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Hans Adolf Buchdahl
Hans Adolf Buchdahl (7 July 1919 – 7 January 2010) was a German-born Australian physicist. He contributed to general relativity, thermodynamics and optics. He is particularly known for developing f(R) gravity and Buchdahl's theorem on the Schwarzschild metric, Schwarzschild's solution for the inside of a spherical star. Biography Hans Adolf Buchdahl was born in Mainz, Germany, in a Jewish family (he used the spelling Adolph to dissociate himself from Hitler). His older brother Gerd Buchdahl was a well-known philosopher in science. In 1933, Gerd took Hans with him to England, to escape the Nazi government. At London, he completed a BSc and received the Associate of the Royal College of Science (ARCS) from Imperial College London, Imperial College. When World War II began, the UK government, unable to determine individual allegiance, interned German nationals including many Jewish refugees already fully assimilated. In July 1940, Hans came to Australia together with Gerd on boa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mainz
Mainz (; #Names and etymology, see below) is the capital and largest city of the German state of Rhineland-Palatinate, and with around 223,000 inhabitants, it is List of cities in Germany by population, Germany's 35th-largest city. It lies in the Frankfurt Rhine-Main, Rhine-Main Metropolitan Region—Germany's second-largest metropolitan region after Rhine-Ruhr—which also encompasses the cities of Frankfurt am Main, Wiesbaden, Darmstadt, Offenbach am Main, and Hanau. Mainz is located at the northern end of the Upper Rhine Plain, on the left bank of the Rhine. It is the largest city of Rhenish Hesse, a region of Rhineland-Palatinate that was historically part of Grand Duchy of Hesse, Hesse, and is Rheinhessen (wine region), one of Germany's most important wine regions because of its mild climate. Mainz is connected to Frankfurt am Main by the Rhine-Main S-Bahn rapid transit system. Before 1945, Mainz had six boroughs on the other side of the Rhine (see: :de:Rechtsrheinische St ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monthly Notices Of The Royal Astronomical Society
''Monthly Notices of the Royal Astronomical Society'' (MNRAS) is a peer-reviewed scientific journal in astronomy, astrophysics and related fields. It publishes original research in two formats: papers (of any length) and letters (limited to five pages). MNRAS publishes more articles per year than any other astronomy journal. The learned society journal has been in continuous existence since 1827 and became online only in 2020. It operates as a partnership between the Royal Astronomical Society (RAS), who select and peer-review the contents, and Oxford University Press (OUP), who publish and market the journal. Despite its name, MNRAS is no longer monthly, nor does it carry the notices of the RAS. In 2024 MNRAS became a purely gold open access journal. History The first issue of MNRAS was published on 9 February 1827 as ''Monthly Notices of the Astronomical Society of London'' and it has been in continuous publication ever since. It took its current name from the second vo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Albert Einstein
Albert Einstein (14 March 187918 April 1955) was a German-born theoretical physicist who is best known for developing the theory of relativity. Einstein also made important contributions to quantum mechanics. His mass–energy equivalence formula , which arises from special relativity, has been called "the world's most famous equation". He received the 1921 Nobel Prize in Physics for . Born in the German Empire, Einstein moved to Switzerland in 1895, forsaking his German citizenship (as a subject of the Kingdom of Württemberg) the following year. In 1897, at the age of seventeen, he enrolled in the mathematics and physics teaching diploma program at the Swiss ETH Zurich, federal polytechnic school in Zurich, graduating in 1900. He acquired Swiss citizenship a year later, which he kept for the rest of his life, and afterwards secured a permanent position at the Swiss Patent Office in Bern. In 1905, he submitted a successful PhD dissertation to the University of Zurich. In 19 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Einstein Field Equation
In the general theory of relativity, the Einstein field equations (EFE; also known as Einstein's equations) relate the geometry of spacetime to the distribution of matter within it. The equations were published by Albert Einstein in 1915 in the form of a tensor equation which related the local ' (expressed by the Einstein tensor) with the local energy, momentum and stress within that spacetime (expressed by the stress–energy tensor). Analogously to the way that electromagnetic fields are related to the distribution of charges and currents via Maxwell's equations, the EFE relate the spacetime geometry to the distribution of mass–energy, momentum and stress, that is, they determine the metric tensor of spacetime for a given arrangement of stress–energy–momentum in the spacetime. The relationship between the metric tensor and the Einstein tensor allows the EFE to be written as a set of nonlinear partial differential equations when used in this way. The solutions of the E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spinor
In geometry and physics, spinors (pronounced "spinner" IPA ) are elements of a complex numbers, complex vector space that can be associated with Euclidean space. A spinor transforms linearly when the Euclidean space is subjected to a slight (infinitesimal transformation, infinitesimal) rotation, but unlike Euclidean vector, geometric vectors and tensors, a spinor transforms to its negative when the space rotates through 360° (see picture). It takes a rotation of 720° for a spinor to go back to its original state. This property characterizes spinors: spinors can be viewed as the "square roots" of vectors (although this is inaccurate and may be misleading; they are better viewed as "square roots" of Section (fiber bundle), sections of vector bundles – in the case of the exterior algebra bundle of the cotangent bundle, they thus become "square roots" of differential forms). It is also possible to associate a substantially similar notion of spinor to Minkowski space, in which cas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tensor
In mathematics, a tensor is an algebraic object that describes a multilinear relationship between sets of algebraic objects associated with a vector space. Tensors may map between different objects such as vectors, scalars, and even other tensors. There are many types of tensors, including scalars and vectors (which are the simplest tensors), dual vectors, multilinear maps between vector spaces, and even some operations such as the dot product. Tensors are defined independent of any basis, although they are often referred to by their components in a basis related to a particular coordinate system; those components form an array, which can be thought of as a high-dimensional matrix. Tensors have become important in physics because they provide a concise mathematical framework for formulating and solving physics problems in areas such as mechanics ( stress, elasticity, quantum mechanics, fluid mechanics, moment of inertia, ...), electrodynamics ( electromagnetic ten ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Constantin Carathéodory
Constantin Carathéodory (; 13 September 1873 – 2 February 1950) was a Greeks, Greek mathematician who spent most of his professional career in Germany. He made significant contributions to real and complex analysis, the calculus of variations, and measure theory. He also created an axiomatic formulation of thermodynamics. Carathéodory is considered one of the greatest mathematicians of his era and the most renowned Greek mathematics, Greek mathematician since Ancient history, antiquity. Origins Constantin Carathéodory was born in 1873 in Berlin to Greeks, Greek parents and grew up in Brussels. His father , a lawyer, served as the Ottoman Empire, Ottoman ambassador to Belgium, St. Petersburg and Berlin. His mother, Despina, née Petrokokkinos, was from the island of Chios. The Carathéodory family, originally from Bosna, Edirne, Bosna, was well established and respected in Istanbul, Constantinople, and its members held many important governmental positions. His grandfather ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical Aberration
In optics, aberration is a property of optical systems, such as Lens (optics), lenses and mirrors, that causes the ''image'' created by the optical system to not be a faithful reproduction of the ''object'' being observed. Aberrations cause the image formed by a lens to be blurred, distorted in shape or have color fringing or other effects not seen in the object, with the nature of the distortion depending on the type of aberration. Aberration can be defined as a departure of the performance of an optical system from the predictions of paraxial optics. In an imaging system, it occurs when light from one point of an object does not converge into (or does not diverge from) a single point after transmission through the system. Aberrations occur because the simple paraxial theory is not a completely accurate model of the effect of an optical system on light, rather than due to flaws in the optical elements. An image-forming optical system with aberration will produce an image which i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canberra
Canberra ( ; ) is the capital city of Australia. Founded following the Federation of Australia, federation of the colonies of Australia as the seat of government for the new nation, it is Australia's list of cities in Australia, largest inland city, and the list of cities in Australia by population, eighth-largest Australian city by population. The city is located at the northern end of the Australian Capital Territory at the northern tip of the Australian Alps, the country's highest mountain range. Canberra's estimated population was 473,855. The area chosen for the capital had been inhabited by Aboriginal Australians for up to 21,000 years, by groups including the Ngunnawal and Ngambri. history of Australia (1788–1850), European settlement commenced in the first half of the 19th century, as evidenced by surviving landmarks such as St John the Baptist Church, Reid, St John's Anglican Church and Blundells Cottage. On 1 January 1901, federation of the colonies of Australi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hobart
Hobart ( ) is the capital and most populous city of the island state of Tasmania, Australia. Located in Tasmania's south-east on the estuary of the River Derwent, it is the southernmost capital city in Australia. Despite containing nearly half of Tasmania's population, Hobart is the least-populated Australian state capital city, and second-smallest by population and area after Darwin if territories are taken into account. Material was copied from this source, which is available under Creative Commons Attribution 4.0 International License Its skyline is dominated by the kunanyi / Mount Wellington, and its harbour forms the second-deepest natural port in the world, with much of the city's waterfront consisting of reclaimed land. The metropolitan area is often referred to as Greater Hobart, to differentiate it from the City of Hobart, one of the seven local government areas that cover the city. It has a mild maritime climate. The city lies on country which was known by the l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HMT Dunera
HMT (Hired Military Transport) ''Dunera'' was a British passenger ship which, in 1940, became involved in a controversial transportation of thousands of "enemy aliens" to Australia. The British India Steam Navigation Company had operated a previous , which served as a troopship during the Second Boer War. Early service as a troopship After sea trial in 1937, she was handed over to the British India Steam Navigation Company and served as a passenger liner and an educational cruise ship before seeing extensive service as a troopship throughout World War II. She was taken over by the Royal Navy as a troopship before hostilities started, and was taking troops to the Far East when her crew heard the news of war at Malta on 3 September 1939. ''Dunera'' carried New Zealand troops to Egypt in January 1940. Transport voyage to Australia Background After Britain declared war on Germany, the government set up aliens tribunals to distinguish Nazi sympathisers from refugees who had fled f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
