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Tobias Mayer
Tobias Mayer (17 February 172320 February 1762) was a German astronomer famous for his studies of the Moon. He was born at Marbach, in Württemberg, and brought up at Esslingen in poor circumstances. A self-taught mathematician, he earned a living by teaching mathematics while still a youth. He had already published two original geometrical works when, in 1746, he entered J. B. Homann's cartographic establishment at Nuremberg. Here he introduced many improvements in mapmaking, and gained a scientific reputation which led (in 1751) to his election to the chair of economy and mathematics at the University of Göttingen. In 1754 he became superintendent of the observatory, where he worked until his death in 1762. Career Mayer's first important astronomical work was a careful investigation of the libration of the Moon (''Kosmographische Nachrichten'', Nuremberg, 1750), and his chart of the full moon (published in 1775) was unsurpassed for half a century. But his fame rests chief ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marbach Am Neckar
Marbach am Neckar is a town about 20 kilometres north of Stuttgart. It belongs to the district of Ludwigsburg, the Stuttgart region and the European metropolitan region of Stuttgart. Marbach is known as the birthplace of Friedrich Schiller, to whom it owes the additional designation of ''Schiller City'', which it has officially held since 2022. The town is home to the Schiller National Museum, the German Literature Archive and the Modern Literature Museum. Geography Geographical location Marbach is located in the Neckar Basin on the eastern bank of a loop of the Neckar, whose impact slope is interrupted by two deep cuts. The northern of the two cuts is flowed through by the largely blocked Strenzelbach stream, the southern by the Eichgraben ditch. Marbach's old town lies on the southern slope of the Strenzelbach valley, some 30 metres above the Neckar, while the newer residential and commercial areas are spread across the slopes further to the north-east, east and sout ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greenwich
Greenwich ( , ,) is a town in south-east London, England, within the ceremonial county of Greater London. It is situated east-southeast of Charing Cross. Greenwich is notable for its maritime history and for giving its name to the Greenwich Meridian (0° longitude) and Greenwich Mean Time. The town became the site of a royal palace, the Palace of Placentia from the 15th century, and was the birthplace of many Tudors, including Henry VIII and Elizabeth I. The palace fell into disrepair during the English Civil War and was demolished to be replaced by the Royal Naval Hospital for Sailors, designed by Sir Christopher Wren and his assistant Nicholas Hawksmoor. These buildings became the Royal Naval College in 1873, and they remained a military education establishment until 1998 when they passed into the hands of the Greenwich Foundation. The historic rooms within these buildings remain open to the public; other buildings are used by University of Greenwich and Trinity Laban C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earth
Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surface is made up of the ocean, dwarfing Earth's polar ice, lakes, and rivers. The remaining 29% of Earth's surface is land, consisting of continents and islands. Earth's surface layer is formed of several slowly moving tectonic plates, which interact to produce mountain ranges, volcanoes, and earthquakes. Earth's liquid outer core generates the magnetic field that shapes the magnetosphere of the Earth, deflecting destructive solar winds. The atmosphere of the Earth consists mostly of nitrogen and oxygen. Greenhouse gases in the atmosphere like carbon dioxide (CO2) trap a part of the energy from the Sun close to the surface. Water vapor is widely present in the atmosphere and forms clouds that cover most of the planet. More solar e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jupiter
Jupiter is the fifth planet from the Sun and the largest in the Solar System. It is a gas giant with a mass more than two and a half times that of all the other planets in the Solar System combined, but slightly less than one-thousandth the mass of the Sun. Jupiter is the third brightest natural object in the Earth's night sky after the Moon and Venus, and it has been observed since prehistoric times. It was named after the Roman god Jupiter, the king of the gods. Jupiter is primarily composed of hydrogen, but helium constitutes one-quarter of its mass and one-tenth of its volume. It probably has a rocky core of heavier elements, but, like the other giant planets in the Solar System, it lacks a well-defined solid surface. The ongoing contraction of Jupiter's interior generates more heat than it receives from the Sun. Because of its rapid rotation, the planet's shape is an oblate spheroid: it has a slight but noticeable bulge around the equator. The outer atmosphere i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perturbation (astronomy)
In astronomy, perturbation is the complex motion of a astronomical object, massive body subjected to forces other than the gravity, gravitational attraction of a single other massive physical body, body. The other forces can include a third (fourth, fifth, etc.) body, drag (physics), resistance, as from an atmosphere, and the off-center attraction of an oblate spheroid, oblate or otherwise misshapen body. Introduction The study of perturbations began with the first attempts to predict planetary motions in the sky. In ancient times the causes were unknown. Isaac Newton, at the time he formulated his laws of Newton's laws of motion, motion and of Newton's law of universal gravitation, gravitation, applied them to the first analysis of perturbations, recognizing the complex difficulties of their calculation. Many of the great mathematicians since then have given attention to the various problems involved; throughout the 18th and 19th centuries there was demand for accurate tables o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mars
Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury. In the English language, Mars is named for the Roman god of war. Mars is a terrestrial planet with a thin atmosphere (less than 1% that of Earth's), and has a crust primarily composed of elements similar to Earth's crust, as well as a core made of iron and nickel. Mars has surface features such as impact craters, valleys, dunes and polar ice caps. It has two small and irregularly shaped moons, Phobos and Deimos. Some of the most notable surface features on Mars include Olympus Mons, the largest volcano and highest known mountain in the Solar System and Valles Marineris, one of the largest canyons in the Solar System. The Borealis basin in the Northern Hemisphere covers approximately 40% of the planet and may be a large impact feature. Days and seasons on Mars are comparable to those of Earth, as the planets have a similar rotation period ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Planetary Orbit
In celestial mechanics, an orbit is the curved trajectory of an object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an artificial satellite around an object or position in space such as a planet, moon, asteroid, or Lagrange point. Normally, orbit refers to a regularly repeating trajectory, although it may also refer to a non-repeating trajectory. To a close approximation, planets and satellites follow elliptic orbits, with the center of mass being orbited at a focal point of the ellipse, as described by Kepler's laws of planetary motion. For most situations, orbital motion is adequately approximated by Newtonian mechanics, which explains gravity as a force obeying an inverse-square law. However, Albert Einstein's general theory of relativity, which accounts for gravity as due to curvature of spacetime, with orbits following geodesics, provides a more accurate calculation and understanding of the exact mechanics of orbital mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proper Motion
Proper motion is the astrometric measure of the observed changes in the apparent places of stars or other celestial objects in the sky, as seen from the center of mass of the Solar System, compared to the abstract background of the more distant stars. The components for proper motion in the equatorial coordinate system (of a given epoch, often J2000.0) are given in the direction of right ascension (''μ''α) and of declination (''μ''δ). Their combined value is computed as the ''total proper motion'' (''μ''). It has dimensions of angle per time, typically arcseconds per year or milliarcseconds per year. Knowledge of the proper motion, distance, and radial velocity allows calculations of an object's motion from our star system's frame of reference and its motion from the galactic frame of reference – that is motion in respect to the Sun, and by coordinate transformation, that in respect to the Milky Way. Introduction Over the course of centuries, stars appear to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zodiac
The zodiac is a belt-shaped region of the sky that extends approximately 8° north or south (as measured in celestial latitude) of the ecliptic, the apparent path of the Sun across the celestial sphere over the course of the year. The paths of the Moon and visible planets are within the belt of the zodiac. In Western astrology, and formerly astronomy, the zodiac is divided into twelve signs, each occupying 30° of celestial longitude and roughly corresponding to the following star constellations: Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricorn, Aquarius, and Pisces. These astrological signs form a celestial coordinate system, or more specifically an ecliptic coordinate system, which takes the ecliptic as the origin of latitude and the Sun's position at vernal equinox as the origin of longitude. Name The English word ' derives from , the Latinized form of the Ancient Greek ( ), meaning "cycle or circle of little animal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eclipse
An eclipse is an astronomical event that occurs when an astronomical object or spacecraft is temporarily obscured, by passing into the shadow of another body or by having another body pass between it and the viewer. This alignment of three celestial objects is known as a syzygy. Apart from syzygy, the term eclipse is also used when a spacecraft reaches a position where it can observe two celestial bodies so aligned. An eclipse is the result of either an occultation (completely hidden) or a transit (partially hidden). The term eclipse is most often used to describe either a solar eclipse, when the Moon's shadow crosses the Earth's surface, or a lunar eclipse, when the Moon moves into the Earth's shadow. However, it can also refer to such events beyond the Earth–Moon system: for example, a planet moving into the shadow cast by one of its moons, a moon passing into the shadow cast by its host planet, or a moon passing into the shadow of another moon. A binary star system ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Georg Christoph Lichtenberg
Georg Christoph Lichtenberg (1 July 1742 – 24 February 1799) was a German physicist, satirist, and Anglophile. As a scientist, he was the first to hold a professorship explicitly dedicated to experimental physics in Germany. He is remembered for his posthumously published notebooks, which he himself called '' sudelbücher'', a description modelled on the English bookkeeping term "waste books" or "scrapbooks", and for his discovery of tree-like electrical discharge patterns now called Lichtenberg figures. Life Georg Christoph Lichtenberg was born in Ober-Ramstadt near Darmstadt, Landgraviate of Hesse-Darmstadt, the youngest of 17 children. His father, Johann Conrad Lichtenberg, was a pastor ascending through the ranks of the church hierarchy, who eventually became superintendent for Darmstadt. Unusually for a clergyman in those times, he seems to have possessed a fair amount of scientific knowledge. Lichtenberg was educated at his parents' house until 10 years old, when he joined ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atmospheric Refraction
Atmospheric refraction is the deviation of light or other electromagnetic wave from a straight line as it passes through the atmosphere due to the variation in air density as a function of height. This refraction is due to the velocity of light through air decreasing (the refractive index increases) with increased density. Atmospheric refraction near the ground produces mirages. Such refraction can also raise or lower, or stretch or shorten, the images of distant objects without involving mirages. Turbulent air can make distant objects appear to twinkle or shimmer. The term also applies to the refraction of sound. Atmospheric refraction is considered in measuring the position of both celestial and terrestrial objects. Astronomical or celestial refraction causes astronomical objects to appear higher above the horizon than they actually are. Terrestrial refraction usually causes terrestrial objects to appear higher than they actually are, although in the afternoon when th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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