|
Karl Schwarzschild
Karl Schwarzschild (; 9 October 1873 – 11 May 1916) was a German physicist and astronomer. Schwarzschild provided the first exact solution to the Einstein field equations of general relativity, for the limited case of a single spherical non-rotating mass, which he accomplished in 1915, the same year that Einstein first introduced general relativity. The Schwarzschild solution, which makes use of Schwarzschild coordinates and the Schwarzschild metric, leads to a derivation of the Schwarzschild radius, which is the size of the event horizon of a non-rotating black hole. Schwarzschild accomplished this while serving in the German army during World War I. He died the following year from the autoimmune disease pemphigus, which he developed while at the Russian front. Various forms of the disease particularly affect people of Ashkenazi Jewish origin. Asteroid 837 Schwarzschilda is named in his honour, as is the large crater ''Schwarzschild'', on the far side of the Moon. Life ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frankfurt Am Main
Frankfurt, officially Frankfurt am Main (; Hessian: , "Frank ford on the Main"), is the most populous city in the German state of Hesse. Its 791,000 inhabitants as of 2022 make it the fifth-most populous city in Germany. Located on its namesake Main River, it forms a continuous conurbation with the neighboring city of Offenbach am Main and its urban area has a population of over 2.3 million. The city is the heart of the larger Rhine-Main metropolitan region, which has a population of more than 5.6 million and is Germany's second-largest metropolitan region after the Rhine-Ruhr region. Frankfurt's central business district, the Bankenviertel, lies about northwest of the geographic center of the EU at Gadheim, Lower Franconia. Like France and Franconia, the city is named after the Franks. Frankfurt is the largest city in the Rhine Franconian dialect area. Frankfurt was a city state, the Free City of Frankfurt, for nearly five centuries, and was one of the most import ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schwarzschild Coordinates
In the theory of Lorentzian manifolds, spherically symmetric spacetimes admit a family of ''nested round spheres''. In such a spacetime, a particularly important kind of coordinate chart is the Schwarzschild chart, a kind of polar spherical coordinate chart on a static and spherically symmetric spacetime, which is ''adapted'' to these nested round spheres. The defining characteristic of Schwarzschild chart is that the radial coordinate possesses a natural geometric interpretation in terms of the surface area and Gaussian curvature of each sphere. However, radial distances and angles are not accurately represented. These charts have many applications in metric theories of gravitation such as general relativity. They are most often used in static spherically symmetric spacetimes. In the case of general relativity, Birkhoff's theorem states that every ''isolated'' spherically symmetric vacuum or electrovacuum solution of the Einstein field equation is static, but this is certainl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
History Of The Jews In Germany
The history of the Jews in Germany goes back at least to the year 321, and continued through the Early Middle Ages (5th to 10th centuries CE) and High Middle Ages (''circa'' 1000–1299 CE) when Jewish immigrants founded the Ashkenazi Jewish community. The community survived under Charlemagne, but suffered during the Crusades. Accusations of well poisoning during the Black Death (1346–53) led to mass slaughter of German Jews and they fled in large numbers to Poland. The Jewish communities of the cities of Mainz, Speyer and Worms became the center of Jewish life during medieval times. "This was a golden age as area bishops protected the Jews resulting in increased trade and prosperity." The First Crusade began an era of persecution of Jews in Germany. Entire communities, like those of Trier, Worms, Mainz and Cologne, were slaughtered. The Hussite Wars became the signal for renewed persecution of Jews. The end of the 15th century was a period of religious hatred that ascribed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frankfurt
Frankfurt, officially Frankfurt am Main (; Hessian: , "Frank ford on the Main"), is the most populous city in the German state of Hesse. Its 791,000 inhabitants as of 2022 make it the fifth-most populous city in Germany. Located on its namesake Main River, it forms a continuous conurbation with the neighboring city of Offenbach am Main and its urban area has a population of over 2.3 million. The city is the heart of the larger Rhine-Main metropolitan region, which has a population of more than 5.6 million and is Germany's second-largest metropolitan region after the Rhine-Ruhr region. Frankfurt's central business district, the Bankenviertel, lies about northwest of the geographic center of the EU at Gadheim, Lower Franconia. Like France and Franconia, the city is named after the Franks. Frankfurt is the largest city in the Rhine Franconian dialect area. Frankfurt was a city state, the Free City of Frankfurt, for nearly five centuries, and was one of the most import ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moon
The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of Australia). The Moon is a planetary-mass object with a differentiated rocky body, making it a satellite planet under the geophysical definitions of the term and larger than all known dwarf planets of the Solar System. It lacks any significant atmosphere, hydrosphere, or magnetic field. Its surface gravity is about one-sixth of Earth's at , with Jupiter's moon Io being the only satellite in the Solar System known to have a higher surface gravity and density. The Moon orbits Earth at an average distance of , or about 30 times Earth's diameter. Its gravitational influence is the main driver of Earth's tides and very slowly lengthens Earth's day. The Moon's orbit around Earth has a sidereal period of 27.3 days. During each synodic period ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schwarzschild (crater)
Schwarzschild is a large lunar impact crater, approximately in diameter. It is located in the northern part of the Moon's far side. The nearest craters of note are Seares to the northeast, and Gamow to the southeast. It was named after German physicist and astronomer Karl Schwarzschild (1873–1916). The somewhat irregular outer rim of Schwarzschild has been overlain by many smaller impact craters, including most notably Schwarzschild K across the southeastern face and Schwarzschild D on the northeastern rim. The rim is roughly circular in form, with an outward bulge along the southwestern side. The rim has been softened and modified by impact erosion, particularly to the northeast. Just to the northeast of Schwarzschild K is a short chain of small craters lying across the rim and inner wall of Schwarzschild. The inner floor of Schwarzschild is relatively level by comparison with the rugged terrain outside, and is particularly flat in the north-northeastern half. There is a re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
837 Schwarzschilda
837 Schwarzschilda, provisional designation 1916 AG, is a low-eccentric, well-observed asteroid from the asteroid belt, orbiting the Sun with a period of 3.48 years at a distance of 2.21–2.39 AU. It was discovered by German astronomer Max Wolf at Heidelberg Observatory on 23 September 1916. The main-belt asteroid was named after physicist and astronomer Karl Schwarzschild (1873–1916), who had died earlier that year. He was director of the observatories in Göttingen and Potsdam, known for his work in photometry, geometrical optics, stellar statistics and theoretical astrophysics, most notably for producing the first exact solutions to Einstein's field equations. At the time, it was custom to give feminized names to minor planets. See also * Meanings of minor planet names: 501–1000 * Schwarzschild radius The Schwarzschild radius or the gravitational radius is a physical parameter in the Schwarzschild solution to Einstein's field equations that corresponds to the radius ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ashkenazi Jews
Ashkenazi Jews ( ; he, יְהוּדֵי אַשְׁכְּנַז, translit=Yehudei Ashkenaz, ; yi, אַשכּנזישע ייִדן, Ashkenazishe Yidn), also known as Ashkenazic Jews or ''Ashkenazim'',, Ashkenazi Hebrew pronunciation: , singular: , Modern Hebrew: are a Jewish diaspora population who coalesced in the Holy Roman Empire around the end of the first millennium CE. Their traditional diaspora language is Yiddish (a West Germanic language with Jewish linguistic elements, including the Hebrew alphabet), which developed during the Middle Ages after they had moved from Germany and France into Northern Europe and Eastern Europe. For centuries, Ashkenazim in Europe used Hebrew only as a sacred language until the revival of Hebrew as a common language in 20th-century Israel. Throughout their numerous centuries living in Europe, Ashkenazim have made many important contributions to its philosophy, scholarship, literature, art, music, and science. The rabbinical term ''A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eastern Front (World War I)
The Eastern Front or Eastern Theater of World War I (german: Ostfront; ro, Frontul de răsărit; russian: Восточный фронт, Vostochny front) was a theater (warfare), theater of operations that encompassed at its greatest extent the entire frontier between Russian Empire, Russia and Kingdom of Romania, Romania on one side and Austria-Hungary, Kingdom of Bulgaria, Bulgaria, the Ottoman Empire, Ottoman Empire, and German Empire, Germany on the other. It stretched from the Baltic Sea in the north to the Black Sea in the south, involved most of Eastern Europe, and stretched deep into Central Europe as well. The term contrasts with "Western Front (World War I), Western Front", which was being fought in Belgium and French Third Republic, France. During 1910, Russian General Yuri Danilov developed "Plan 19" under which four armies would invade East Prussia. This plan was criticised as Austria-Hungary could be a greater threat than the German Empire. So instead of four arm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pemphigus
Pemphigus ( or ) is a rare group of blistering autoimmune diseases that affect the skin and mucous membranes. The name is derived from the Greek root ''pemphix'', meaning "pustule". In pemphigus, autoantibodies form against desmoglein, which forms the "glue" that attaches adjacent epidermal cells via attachment points called desmosomes. When autoantibodies attack desmogleins, the cells become separated from each other and the epidermis becomes detached, a phenomenon called acantholysis. This causes blisters that slough off and turn into sores. In some cases, these blisters can cover a large area of the skin. Originally, the cause of this disease was unknown, and "pemphigus" was used to refer to any blistering disease of the skin and mucosa. In 1964, researchers found that the blood of patients with pemphigus contained antibodies to the layers of skin that separate to form the blisters. In 1971, an article investigating the autoimmune nature of this disease was published ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autoimmunity
In immunology, autoimmunity is the system of immune responses of an organism against its own healthy cells, tissues and other normal body constituents. Any disease resulting from this type of immune response is termed an "autoimmune disease". Prominent examples include celiac disease, post-infectious IBS, diabetes mellitus type 1, Henoch–Schönlein purpura (HSP) sarcoidosis, systemic lupus erythematosus (SLE), Sjögren syndrome, eosinophilic granulomatosis with polyangiitis, Hashimoto's thyroiditis, Graves' disease, idiopathic thrombocytopenic purpura, Addison's disease, rheumatoid arthritis (RA), ankylosing spondylitis, polymyositis (PM), dermatomyositis (DM), Alopecia Areata and multiple sclerosis (MS). Autoimmune diseases are very often treated with steroids. Autoimmunity means presence of antibodies or T cells that react with self-protein and is present in all individuals, even in normal health state. It causes autoimmune diseases if self-reactivity can lead to tiss ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Black Hole
A black hole is a region of spacetime where gravitation, gravity is so strong that nothing, including light or other Electromagnetic radiation, electromagnetic waves, has enough energy to escape it. The theory of general relativity predicts that a sufficiently compact mass can deform spacetime to form a black hole. The boundary (topology), boundary of no escape is called the event horizon. Although it has a great effect on the fate and circumstances of an object crossing it, it has no locally detectable features according to general relativity. In many ways, a black hole acts like an ideal black body, as it reflects no light. Moreover, quantum field theory in curved spacetime predicts that event horizons emit Hawking radiation, with thermal radiation, the same spectrum as a black body of a temperature inversely proportional to its mass. This temperature is of the order of billionths of a kelvin for stellar black holes, making it essentially impossible to observe directly. Obje ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.svg "Click for more on -> Moon")
