An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They observe astronomical objects such as stars, moons and galaxies – in either observational or theoretical astronomy. Examples of topics or fields astronomers study include planetary science, solar astronomy, the origin or evolution of stars, or the formation of galaxies. Related but distinct subjects like physical cosmology. Astronomers fall under either of two main types: observational and theoretical. Observational astronomers analyze the data. In contrast, theoretical astronomers create and investigate models of things that cannot be observed; because it takes millions to billions of years for a system of stars or a galaxy to complete a life cycle, astronomers must observe snapshots of different systems at unique points in their evolution to determine how they form and die. They use these data to create models or simulations to theorize how different celestial objects work.
Further subcategories under these two main branches of astronomy include planetary astronomy, galactic astronomy, or physical cosmology. Astronomy was more concerned with the classification and description of phenomena in the sky, while astrophysics attempted to explain these phenomena and the differences between them using physical laws. Today, that distinction has disappeared and the terms "astronomer" and "astrophysicist" are interchangeable. Professional astronomers are educated individuals who have a Ph. D. in physics or astronomy and are employed by research institutions or universities. They spend the majority of their time working on research, although they quite have other duties such as teaching, building instruments, or aiding in the operation of an observatory; the number of professional astronomers in the United States is quite small. The American Astronomical Society, the major organization of professional astronomers in North America, has 7,000 members; this number includes scientists from other fields such as physics and engineering, whose research interests are related to astronomy.
The International Astronomical Union comprises 10,145 members from 70 different countries who are involved in astronomical research at the Ph. D. beyond. Contrary to the classical image of an old astronomer peering through a telescope through the dark hours of the night, it is far more common to use a charge-coupled device camera to record a long, deep exposure, allowing a more sensitive image to be created because the light is added over time. Before CCDs, photographic plates were a common method of observation. Modern astronomers spend little time at telescopes just a few weeks per year. Analysis of observed phenomena, along with making predictions as to the causes of what they observe, takes the majority of observational astronomers' time. Astronomers who serve as faculty spend much of their time teaching undergraduate and graduate classes. Most universities have outreach programs including public telescope time and sometimes planetariums as a public service to encourage interest in the field.
Those who become astronomers have a broad background in maths and computing in high school. Taking courses that teach how to research and present papers are invaluable. In college/university most astronomers get a Ph. D. in astronomy or physics. While there is a low number of professional astronomers, the field is popular among amateurs. Most cities have amateur astronomy clubs that meet on a regular basis and host star parties; the Astronomical Society of the Pacific is the largest general astronomical society in the world, comprising both professional and amateur astronomers as well as educators from 70 different nations. Like any hobby, most people who think of themselves as amateur astronomers may devote a few hours a month to stargazing and reading the latest developments in research. However, amateurs span the range from so-called "armchair astronomers" to the ambitious, who own science-grade telescopes and instruments with which they are able to make their own discoveries and assist professional astronomers in research.
List of astronomers List of women astronomers List of Muslim astronomers List of French astronomers List of Hungarian astronomers List of Russian astronomers and astrophysicists List of Slovenian astronomers Dallal, Ahmad. "Science and Technology". In Esposito, John; the Oxford History of Islam. Oxford University Press, New York. ISBN 0-300-15911-0. Kennedy, E. S.. "A Survey of Islamic Astronomical Tables. 46. Philadelphia: American Philosophical Society. Toomer, Gerald. "Al-Khwārizmī, Abu Jaʿfar Muḥammad ibn Mūsā". In Gillispie, Charles Coulston. Dictionary of Scientific Biography. 7. New York: Charles Scribner's Sons. ISBN 0-684-16962-2. American Astronomical Society European Astronomical Society International Astronomical Union Astronomical Society of the Pacific Space's astronomy news
A Zeiss projector is one of a line of planetarium projectors manufactured by the Carl Zeiss Company. The first modern planetarium projectors were designed and built in 1924 by the Zeiss Works of Jena, Germany in 1924. Zeiss projectors are designed to sit in the middle of a dark, dome-covered room and project an accurate image of the stars and other astronomical objects on the dome, they are large and imposing machines. The first Zeiss Mark I projector was installed in the Deutsches Museum in Munich in August, 1923, it possessed a distinctive appearance, with a single sphere of projection lenses supported above a large, angled "planet cage". Marks II through VI were similar in appearance, using two spheres of star projectors separated along a central axis that contained projectors for the planets. Beginning with Mark VII, the central axis was eliminated and the two spheres were merged into a single, egg-shaped projection unit; the Mark I was the world's first modern planetarium projector. The Mark II was developed during the 1930s by Carl Zeiss AG in Jena.
Following WWII division of Germany and the founding of Carl Zeiss in Oberkochen, each factory developed its own line of projectors.. Marks III – VI were developed in Oberkochen from 1957–1989. Meanwhile, the East German facility in Jena developed the ZKP projector line; the Mark VII was developed in 1993 and was the first joint project of the two Zeiss factories following German reunification. As of 2011, Zeiss manufactures three main models of planetarium projectors; the flagship Universarium models continue the "Mark" model designation and use a single "starball" design, where the fixed stars are projected from a single egg-shaped projector, moving objects such as planets have their own independent projectors or are projected using a full-dome digital projection system. The Starmaster line of projectors are designed for smaller domes than the Universarium, but use the single starball design; the Skymaster ZKP projectors are designed for the smallest domes and use a "dumbbell" design similar to the Mark II-VI projectors, where two smaller starballs for the northern and southern hemispheres are connected by a truss containing projectors for planets and other moving objects.
Between 1923 and 2011, Zeiss manufactured a total of 631 projectors. Therefore, the following table is incomplete. List of planetariums Planetarium Planetarium Jena Walther Bauersfeld Zeiss Planetariums
Munich is the capital and most populous city of Bavaria, the second most populous German federal state. With a population of around 1.5 million, it is the third-largest city in Germany, after Berlin and Hamburg, as well as the 12th-largest city in the European Union. The city's metropolitan region is home to 6 million people. Straddling the banks of the River Isar north of the Bavarian Alps, it is the seat of the Bavarian administrative region of Upper Bavaria, while being the most densely populated municipality in Germany. Munich is the second-largest city in the Bavarian dialect area, after the Austrian capital of Vienna; the city is a global centre of art, technology, publishing, innovation, education and tourism and enjoys a high standard and quality of living, reaching first in Germany and third worldwide according to the 2018 Mercer survey, being rated the world's most liveable city by the Monocle's Quality of Life Survey 2018. According to the Globalization and World Rankings Research Institute Munich is considered an alpha-world city, as of 2015.
Munich is a major international center of engineering, science and research, exemplified by the presence of two research universities, a multitude of scientific institutions in the city and its surroundings, world class technology and science museums like the Deutsches Museum and BMW Museum.. Munich houses many multinational companies and its economy is based on high tech, the service sector and creative industries, as well as IT, biotechnology and electronics among many others; the name of the city is derived from the Old/Middle High German term Munichen, meaning "by the monks". It derives from the monks of the Benedictine order, who ran a monastery at the place, to become the Old Town of Munich. Munich was first mentioned in 1158. Catholic Munich resisted the Reformation and was a political point of divergence during the resulting Thirty Years' War, but remained physically untouched despite an occupation by the Protestant Swedes. Once Bavaria was established as a sovereign kingdom in 1806, it became a major European centre of arts, architecture and science.
In 1918, during the German Revolution, the ruling house of Wittelsbach, which had governed Bavaria since 1180, was forced to abdicate in Munich and a short-lived socialist republic was declared. In the 1920s, Munich became home to several political factions, among them the NSDAP; the first attempt of the Nazi movement to take over the German government in 1923 with the Beer Hall Putsch was stopped by the Bavarian police in Munich with gunfire. After the Nazis' rise to power, Munich was declared their "Capital of the Movement". During World War II, Munich was bombed and more than 50% of the entire city and up to 90% of the historic centre were destroyed. After the end of postwar American occupation in 1949, there was a great increase in population and economic power during the years of Wirtschaftswunder, or "economic miracle". Unlike many other German cities which were bombed, Munich restored most of its traditional cityscape and hosted the 1972 Summer Olympics; the 1980s brought strong economic growth, high-tech industries and scientific institutions, population growth.
The city is home to major corporations like BMW, Siemens, MAN, Linde and MunichRE. Munich is home to many universities and theatres, its numerous architectural attractions, sports events and its annual Oktoberfest attract considerable tourism. Munich is one of the fastest growing cities in Germany, it is a top-ranked destination for expatriate location. Munich hosts more than 530,000 people of foreign background; the first known settlement in the area was of Benedictine monks on the Salt road. The foundation date is not considered the year 1158, the date the city was first mentioned in a document; the document was signed in Augsburg. By the Guelph Henry the Lion, Duke of Saxony and Bavaria, had built a toll bridge over the river Isar next to the monk settlement and on the salt route, but as part of the archaeological excavations at Marienhof in advance of the expansion of the S-Bahn from 2012 shards of vessels from the eleventh century were found, which prove again that the settlement Munich must be older than their first documentary mention from 1158.
In 1175 Munich received city fortification. In 1180 with the trial of Henry the Lion, Otto I Wittelsbach became Duke of Bavaria, Munich was handed to the Bishop of Freising. In 1240, Munich was transferred to Otto II Wittelsbach and in 1255, when the Duchy of Bavaria was split in two, Munich became the ducal residence of Upper Bavaria. Duke Louis IV, a native of Munich, was elected German king in 1314 and crowned as Holy Roman Emperor in 1328, he strengthened the city's position by granting it the salt monopoly, thus assuring it of additional income. In the late 15th century, Munich underwent a revival of gothic arts: the Old Town Hall was enlarged, Munich's largest gothic church – the Frauenkirche – now a cathedral, was constructed in only 20 years, starting in 1468; when Bavaria was reunited in 1506, Munich became its capital. The arts and politics became influenced by the court. During the 16th century, Munich was a centre of the German counter reformation, of renaissance arts. Duke Wilhelm V commissioned the Jesuit Michaelskirche, which became a centre for the counter-reform
The Deutsches Museum in Munich, Germany, is the world's largest museum of science and technology, with about 28,000 exhibited objects from 50 fields of science and technology. It receives about 1.5 million visitors per year. The museum was founded on 28 June 1903, at a meeting of the Association of German Engineers as an initiative of Oskar von Miller, it is the largest museum in Munich. For a period of time the museum was used to host pop and rock concerts including The Who, Jimi Hendrix and Elton John; the main site of the Deutsches Museum is a small island in the Isar river, used for rafting wood since the Middle Ages. The island did not have any buildings before 1772 because it was flooded prior to the building of the Sylvensteinspeicher. In 1772 the Isar barracks were built on the island and, after the flooding of 1899, the buildings were rebuilt with flood protection. In 1903 the city council announced that they would donate the island for the newly built Deutsches Museum; the island known as Kohleninsel was renamed Museumsinsel.
In addition to the main site on the Museumsinsel, the museum has two branches in and near Munich and one in Bonn. The Flugwerft Schleißheim branch is located some 18 kilometres north of Munich's city centre close to Schleißheim Palace, it is based on the premises of one of the first military airbases in Germany founded just before World War I. It comprises the old air control and command centre as well as modern buildings added in the late 2000s after strong endorsement from Franz-Josef Strauss, the prime minister of the state of Bavaria, a passionate flyer; the Flugwerft Schleißheim displays various interesting airplanes for which there was insufficient room at the Museumsinsel site in downtown Munich. Among the more prominent exhibits is a Horten flying wing glider built in the 1940s, restored from the few surviving parts. A collection of the German constructions of VTOL planes developed in the 1950s and 1960s is unique. A range of Vietnam era fighter planes as well as Russian planes taken over from East Germany after the reunification are on display.
This outstation features a workshop dedicated to the restoration of all types of airplanes intended for static display. The latest branch opened in 2003 and is called the Deutsches Museum Verkehrszentrum, located at Theresienhöhe in Munich, focuses on transportation technology; the branch located in Bonn was opened in 1995 and focuses on German technology and research after 1945. Oskar von Miller studied electrical engineering and is otherwise known for building the first high voltage line from Miesbach to Munich in 1882 for the electrical technology exhibition at the Glaspalast in Munich. In 1883 he founded an engineering office in Munich; the Frankfurt electricity exhibition in 1891 and several power plants contributed to the reputation of Oskar von Miller. In the early years, the exhibition and the collection of the Deutsches Museum were influenced by Oskar von Miller. A few months before the 1903 meeting of the Society of German Engineers, Oskar von Miller gathered a small group who supported his desire to found a science and technology museum.
In a showing of support this group spontaneously donated 260,000 marks to the cause and elected a "Provisional Committee" to get the ball rolling. In June 1903, Prince Ludwig agreed to act as patron of the museum and the city of Munich donated Coal Island as a site for the project. In addition, exhibits began to arrive from Munich and abroad including collections from the Bavarian Academy; as no dedicated museum building existed, the exhibits were displayed in the National Museum. On 12 November 1906, the temporary exhibits at the National Museum were ceremonially opened to the public and on November 13 the foundation stone was laid for the permanent museum; the first name of the museum, the "German Museum for Masterpieces of Natural Science and Technology", was not meant to limit the museum to German advances in science and technology, but to express the importance of science and technology to the German people. Oskar von Miller opened the new museum on his 70th birthday, 2 May 1925, after a delay of ten years.
From the beginning, the museum displays are backed up by documents available in a public library and archives, which are open seven days a week to ensure access to the working public. Before and during World War II the museum was put on a shoestring budget by the Nazi party and many exhibits were allowed to get out of date with a few exceptions such as the new automobile room dedicated 7 May 1937. By the end of 1944 the museum was badly damaged by air bombings with 80% of the buildings and 20% of the exhibits damaged or destroyed; as Allied troops marched into Munich in April 1945, museum director, Karl Bässler managed to keep the last standing bridge to Museum Island from being blown up by retreating German troops. Following the war the museum had to be closed for repairs and temporary tenants, such as the College of Technology and the Post Office used museum space as their own buildings were being reconstructed; the Museum was home to the Central Committee of the Liberated Jews, representing Jewish displaced persons in the American Zone of Germany after the war.
In November 1945, the library was able to reopen, followed by the congress hall in January 1946. A special exhibit on fifty years of the Diesel engine opened in October 1947 and the regular exhibits began reopening in May 1948. Not until 1965, more than twenty years after the end of the war in Germany, did the exhibit area match (and e
A planetarium is a theatre built for presenting educational and entertaining shows about astronomy and the night sky, or for training in celestial navigation. A dominant feature of most planetaria is the large dome-shaped projection screen onto which scenes of stars and other celestial objects can be made to appear and move realistically to simulate the complex'motions of the heavens'; the celestial scenes can be created using a wide variety of technologies, for example precision-engineered'star balls' that combine optical and electro-mechanical technology, slide projector and fulldome projector systems, lasers. Whatever technologies are used, the objective is to link them together to simulate an accurate relative motion of the sky. Typical systems can be set to simulate the sky at any point in time, past or present, to depict the night sky as it would appear from any point of latitude on Earth. Planetariums range in size from the 37 meter dome in St. Petersburg, Russia to three-meter inflatable portable domes where attendees sit on the floor.
The largest planetarium in the Western Hemisphere is the Jennifer Chalsty Planetarium at Liberty Science Center in New Jersey. The Birla Planetarium in Kolkata, India is the largest by seating capacity. Thereafter, the China Science and Technology Museum Planetarium in Beijing, China has the largest seating capacity. In North America, the Hayden Planetarium at the American Museum of Natural History in New York City has the greatest number of seats; the term planetarium is sometimes used generically to describe other devices which illustrate the solar system, such as a computer simulation or an orrery. Planetarium software refers to a software application that renders a three-dimensional image of the sky onto a two-dimensional computer screen; the term planetarian is used to describe a member of the professional staff of a planetarium. The ancient Greek polymath Archimedes is attributed with creating a primitive planetarium device that could predict the movements of the Sun and the Moon and the planets.
The discovery of the Antikythera mechanism proved that such devices existed during antiquity, though after Archimedes' lifetime. Campanus of Novara described a planetary equatorium in his Theorica Planetarum, included instructions on how to build one; the Globe of Gottorf built around 1650 had constellations painted on the inside. These devices would today be referred to as orreries. In fact, many planetaria today have what are called projection orreries, which project onto the dome a Sun with planets going around it in something close to their correct relative periods; the small size of typical 18th century orreries limited their impact, towards the end of that century a number of educators attempted some larger scale simulations of the heavens. The efforts of Adam Walker and his sons are noteworthy in their attempts to fuse theatrical illusions with educational aspirations. Walker's Eidouranion was the heart of theatrical presentations. Walker's son describes this "Elaborate Machine" as "twenty feet high, twenty-seven in diameter: it stands vertically before the spectators, its globes are so large, that they are distinctly seen in the most distant parts of the Theatre.
Every Planet and Satellite seems suspended without any support. Other lecturers promoted their own devices: R E Lloyd advertised his Dioastrodoxon, or Grand Transparent Orrery, by 1825 William Kitchener was offering his Ouranologia, 42 feet in diameter; these devices most sacrificed astronomical accuracy for crowd-pleasing spectacle and sensational and awe-provoking imagery. The oldest, still working planetarium can be found in the Dutch town Franeker, it was built by Eise Eisinga in the living room of his house. It took Eisinga seven years to build his planetarium, completed in 1781. In 1905 Oskar von Miller of the Deutsches Museum in Munich commissioned updated versions of a geared orrery and planetarium from M Sendtner, worked with Franz Meyer, chief engineer at the Carl Zeiss optical works in Jena, on the largest mechanical planetarium constructed, capable of displaying both heliocentric and geocentric motion; this was displayed at the Deutsches Museum in 1924, construction work having been interrupted by the war.
The planets travelled along overhead rails, powered by electric motors: the orbit of Saturn was 11.25 m in diameter. 180 stars were projected onto the wall by electric bulbs. While this was being constructed, von Miller was working at the Zeiss factory with German astronomer Max Wolf, director of the Landessternwarte Heidelberg-Königstuhl observatory of the University of Heidelberg, on a new and novel design, inspired by Wallace W. Atwood's work at the Chicago Academy of Sciences and by the ideas of Walther Bauersfeld and Rudolf Straubel at Zeiss; the result was a planetarium design which would generate all the necessary movements of the stars and planets inside the optical projector, would be mounted centrally in a room, projecting images onto the white surface of a hemisphere. In August 1923, the first Zeiss planetarium projected images of the night sky onto the white plaster lining of a 16 m hemispherical concrete dome, erected on the roof of the Zeiss works; the first official public showing was at the Deutsches Museum in Munich on October 21, 1923.
When Germany was divided into East and West Germany
Integrated Authority File
The Integrated Authority File or GND is an international authority file for the organisation of personal names, subject headings and corporate bodies from catalogues. It is used for documentation in libraries and also by archives and museums; the GND is managed by the German National Library in cooperation with various regional library networks in German-speaking Europe and other partners. The GND falls under the Creative Commons Zero licence; the GND specification provides a hierarchy of high-level entities and sub-classes, useful in library classification, an approach to unambiguous identification of single elements. It comprises an ontology intended for knowledge representation in the semantic web, available in the RDF format; the Integrated Authority File became operational in April 2012 and integrates the content of the following authority files, which have since been discontinued: Name Authority File Corporate Bodies Authority File Subject Headings Authority File Uniform Title File of the Deutsches Musikarchiv At the time of its introduction on 5 April 2012, the GND held 9,493,860 files, including 2,650,000 personalised names.
There are seven main types of GND entities: LIBRIS Virtual International Authority File Information pages about the GND from the German National Library Search via OGND Bereitstellung des ersten GND-Grundbestandes DNB, 19 April 2012 From Authority Control to Linked Authority Data Presentation given by Reinhold Heuvelmann to the ALA MARC Formats Interest Group, June 2012
Asteroids are minor planets of the inner Solar System. Larger asteroids have been called planetoids; these terms have been applied to any astronomical object orbiting the Sun that did not resemble a planet-like disc and was not observed to have characteristics of an active comet such as a tail. As minor planets in the outer Solar System were discovered they were found to have volatile-rich surfaces similar to comets; as a result, they were distinguished from objects found in the main asteroid belt. In this article, the term "asteroid" refers to the minor planets of the inner Solar System including those co-orbital with Jupiter. There exist millions of asteroids, many thought to be the shattered remnants of planetesimals, bodies within the young Sun's solar nebula that never grew large enough to become planets; the vast majority of known asteroids orbit within the main asteroid belt located between the orbits of Mars and Jupiter, or are co-orbital with Jupiter. However, other orbital families exist with significant populations, including the near-Earth objects.
Individual asteroids are classified by their characteristic spectra, with the majority falling into three main groups: C-type, M-type, S-type. These were named after and are identified with carbon-rich and silicate compositions, respectively; the sizes of asteroids varies greatly. Asteroids are differentiated from meteoroids. In the case of comets, the difference is one of composition: while asteroids are composed of mineral and rock, comets are composed of dust and ice. Furthermore, asteroids formed closer to the sun; the difference between asteroids and meteoroids is one of size: meteoroids have a diameter of one meter or less, whereas asteroids have a diameter of greater than one meter. Meteoroids can be composed of either cometary or asteroidal materials. Only one asteroid, 4 Vesta, which has a reflective surface, is visible to the naked eye, this only in dark skies when it is favorably positioned. Small asteroids passing close to Earth may be visible to the naked eye for a short time; as of October 2017, the Minor Planet Center had data on 745,000 objects in the inner and outer Solar System, of which 504,000 had enough information to be given numbered designations.
The United Nations declared 30 June as International Asteroid Day to educate the public about asteroids. The date of International Asteroid Day commemorates the anniversary of the Tunguska asteroid impact over Siberia, Russian Federation, on 30 June 1908. In April 2018, the B612 Foundation reported "It's 100 percent certain we'll be hit, but we're not 100 percent sure when." In 2018, physicist Stephen Hawking, in his final book Brief Answers to the Big Questions, considered an asteroid collision to be the biggest threat to the planet. In June 2018, the US National Science and Technology Council warned that America is unprepared for an asteroid impact event, has developed and released the "National Near-Earth Object Preparedness Strategy Action Plan" to better prepare. According to expert testimony in the United States Congress in 2013, NASA would require at least five years of preparation before a mission to intercept an asteroid could be launched; the first asteroid to be discovered, was considered to be a new planet.
This was followed by the discovery of other similar bodies, with the equipment of the time, appeared to be points of light, like stars, showing little or no planetary disc, though distinguishable from stars due to their apparent motions. This prompted the astronomer Sir William Herschel to propose the term "asteroid", coined in Greek as ἀστεροειδής, or asteroeidēs, meaning'star-like, star-shaped', derived from the Ancient Greek ἀστήρ astēr'star, planet'. In the early second half of the nineteenth century, the terms "asteroid" and "planet" were still used interchangeably. Overview of discovery timeline: 10 by 1849 1 Ceres, 1801 2 Pallas – 1802 3 Juno – 1804 4 Vesta – 1807 5 Astraea – 1845 in 1846, planet Neptune was discovered 6 Hebe – July 1847 7 Iris – August 1847 8 Flora – October 1847 9 Metis – 25 April 1848 10 Hygiea – 12 April 1849 tenth asteroid discovered 100 asteroids by 1868 1,000 by 1921 10,000 by 1989 100,000 by 2005 ~700,000 by 2015 Asteroid discovery methods have improved over the past two centuries.
In the last years of the 18th century, Baron Franz Xaver von Zach organized a group of 24 astronomers to search the sky for the missing planet predicted at about 2.8 AU from the Sun by the Titius-Bode law because of the discovery, by Sir William Herschel in 1781, of the planet Uranus at the distance predicted by the law. This task required that hand-drawn sky charts be prepared for all stars in the zodiacal band down to an agreed-upon limit of faintness. On subsequent nights, the sky would be charted again and any moving object would be spotted; the expected motion of the missing planet was about 30 seconds of arc per hour discernible by observers. The first object, was not discovered by a member of the group, but rather by accident in 1801 by Giuseppe Piazzi, director of the observatory of Palermo in Sicily, he discovered a new star-like object in Taurus and followed the displacement of this object during several nights. That year, Carl Friedrich Gauss used these observations to calculate the orbit of this unknown object, found to be between the planets Mars and Jupiter.
Piazzi named it after Ceres, the Roman goddess of agriculture. Three other asteroids (2 Pallas, 3 Juno, 4 Ves