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Astronomical Observatories
An observatory is a location used for observing terrestrial, marine, or celestial events. Astronomy, climatology/meteorology, geophysics, oceanography and volcanology are examples of disciplines for which observatories have been constructed. The term ''observatoire'' has been used in French since at least 1976 to denote any institution that compiles and presents data on a particular subject (such as public health observatory) or for a particular geographic area (European Audiovisual Observatory). Astronomical observatories Astronomical observatories are mainly divided into four categories: space observatory, space-based, airborne observatory, airborne, ground-based, and underground-based. Historically, ground-based observatories were as simple as containing a mural instrument (for measuring the angle between stars) or Stonehenge (which has some alignments on astronomical phenomena). Ground-based observatories Ground-based observatories, located on the surface of Earth, are u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Royal Observatory Greenwich
Royal may refer to: People * Royal (name), a list of people with either the surname or given name * A member of a royal family or Royalty (other), royalty Places United States * Royal, Arkansas, an unincorporated community * Royal, Illinois, a village * Royal, Iowa, a city * Royal, Missouri, an unincorporated community * Royal, Nebraska, a village * Royal, Franklin County, North Carolina, an unincorporated area * Royal, Utah, a ghost town * Royal, West Virginia, an unincorporated community * Royal Gorge, on the Arkansas River in Colorado * Royal Township (other) Elsewhere * Mount Royal, a hill in Montreal, Canada * Royal Canal, Dublin, Ireland * Royal National Park, New South Wales, Australia Arts, entertainment, and media * Royal (Jesse Royal album), ''Royal'' (Jesse Royal album), 2021 * Royal (Ayo album), 2020 * ''The Royal'', a British medical drama television series * ''The Royal Magazine'', a monthly British literary magazine published between 1898 and 19 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mauna Kea Observatories
The Mauna Kea Observatories (MKO) are a group of independent astronomical research facilities and large telescope observatories that are located at the summit of Mauna Kea on Hawaii (island), Hawaiʻi, United States. The facilities are located in a 525-acre (212 ha) special land use zone known as the "Astronomy Precinct", which is located within the 11,228-acre (4,544 ha) Mauna Kea Science Reserve. The Astronomy Precinct was established in 1967 and is located on land protected by the National Historic Preservation Act of 1966, Historical Preservation Act for its significance to Hawaiian culture. The presence and continued construction of telescopes Opposition to the Mauna Kea Observatories, is highly controversial due to Mauna Kea's centrality in native Hawaiian religion and culture, as well as for a variety of environmental reasons. The location is near ideal because of its light pollution, dark skies from lack of light pollution, good astronomical seeing, low Relative ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hawaii
Hawaii ( ; ) is an island U.S. state, state of the United States, in the Pacific Ocean about southwest of the U.S. mainland. One of the two Non-contiguous United States, non-contiguous U.S. states (along with Alaska), it is the only state not on the North American mainland, the only state that is an archipelago, and the only state in the tropics. Hawaii consists of 137 volcanic islands that comprise almost the entire Hawaiian Islands, Hawaiian archipelago (the exception, which is outside the state, is Midway Atoll). Spanning , the state is Physical geography, physiographically and Ethnology, ethnologically part of the Polynesian subregion of Oceania. Hawaii's ocean coastline is consequently the List of U.S. states and territories by coastline, fourth-longest in the U.S., at about . The eight main islands, from northwest to southeast, are Niihau, Niihau, Kauai, Kauai, Oahu, Oahu, Molokai, Molokai, Lanai, Lānai, Kahoʻolawe, Kahoolawe, Maui, and Hawaii (island), Hawaii, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Southwestern United States
The Southwestern United States, also known as the American Southwest or simply the Southwest, is a geographic and cultural list of regions of the United States, region of the United States that includes Arizona and New Mexico, along with adjacent portions of California, Colorado, Nevada, Oklahoma, Texas, and Utah. The largest cities by List of metropolitan statistical areas, metropolitan area are Phoenix, Arizona, Phoenix, Las Vegas, El Paso, Texas, El Paso, Albuquerque, and Tucson, Arizona, Tucson. Before 1848, in the historical region of Santa Fe de Nuevo México as well as parts of Alta California and Coahuila y Tejas, settlement was almost non-existent outside of New Mexico's pueblos and Santa Fe de Nuevo México#Regions and municipalities, Spanish or Mexican municipalities. Much of the area had been a part of New Spain and Mexico until the United States acquired the area through the Treaty of Guadalupe Hidalgo in 1848 and the smaller Gadsden Purchase in 1854. While the regio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prentice Hall
Prentice Hall was a major American publishing#Textbook_publishing, educational publisher. It published print and digital content for the 6–12 and higher-education market. It was an independent company throughout the bulk of the twentieth century. In its last few years it was owned by, then absorbed into, Savvas Learning Company. In the Web era, it distributed its technical titles through the Safari Books Online e-reference service for some years. History On October 13, 1913, law professor Charles Gerstenberg and his student Richard Ettinger founded Prentice Hall. Gerstenberg and Ettinger took their mothers' maiden names, Prentice and Hall, to name their new company. At the time the name was usually styled as Prentice-Hall (as seen for example on many title pages), per an orthographic norm for Dash#Relationships and connections, coordinate elements within such compounds (compare also ''McGraw-Hill'' with later styling as ''McGraw Hill''). Prentice-Hall became known as a publi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomical Seeing
In astronomy, seeing is the degradation of the real image, image of an astronomical object due to turbulence in the atmosphere of Earth that may become visible as blurring, twinkling or variable Distortion (optics), distortion. The origin of this effect is rapidly changing variations of the optical refractive index along the light path from the object to the detector. Seeing is a major limitation to the angular resolution in astronomical observations with telescopes that would otherwise be Angular resolution#The Rayleigh criterion, limited through diffraction by the size of the telescope aperture. Today, many large scientific ground-based optical telescopes include adaptive optics to overcome seeing. The strength of seeing is often characterized by the angular diameter of the long-exposure image of a star (''seeing disk'') or by the Fried parameter ''r''0. The diameter of the seeing disk is the full width at half maximum of its optical intensity. An exposure time of several tens o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atmospheric Turbulence
In fluid dynamics, turbulence or turbulent flow is fluid motion characterized by chaotic changes in pressure and flow velocity. It is in contrast to laminar flow, which occurs when a fluid flows in parallel layers with no disruption between those layers. Turbulence is commonly observed in everyday phenomena such as surf, fast flowing rivers, billowing storm clouds, or smoke from a chimney, and most fluid flows occurring in nature or created in engineering applications are turbulent. Turbulence is caused by excessive kinetic energy in parts of a fluid flow, which overcomes the damping effect of the fluid's viscosity. For this reason, turbulence is commonly realized in low viscosity fluids. In general terms, in turbulent flow, unsteady vortices appear of many sizes which interact with each other, consequently drag due to friction effects increases. The onset of turbulence can be predicted by the dimensionless Reynolds number, the ratio of kinetic energy to viscous damping in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earth's Atmosphere
The atmosphere of Earth is composed of a layer of gas mixture that surrounds the Earth's planetary surface (both lands and oceans), known collectively as air, with variable quantities of suspended aerosols and particulates (which create weather features such as clouds and hazes), all retained by Earth's gravity. The atmosphere serves as a protective buffer between the Earth's surface and outer space, shields the surface from most meteoroids and ultraviolet solar radiation, keeps it warm and reduces diurnal temperature variation (temperature extremes between day and night) through heat retention (greenhouse effect), redistributes heat and moisture among different regions via air currents, and provides the chemical and climate conditions allowing life to exist and evolve on Earth. By mole fraction (i.e., by quantity of molecules), dry air contains 78.08% nitrogen, 20.95% oxygen, 0.93% argon, 0.04% carbon dioxide, and small amounts of other trace gases (see Composition below ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Light Pollution
Light pollution is the presence of any unwanted, inappropriate, or excessive artificial Visible spectrum, lighting. In a descriptive sense, the term ''light pollution'' refers to the effects of any poorly implemented lighting sources, during the day or night. Light pollution can be understood not only as a phenomenon resulting from a specific source or kind of pollution, but also as a contributor to the wider, collective impact of various sources of pollution. Although this type of pollution can exist throughout the day, its effects are magnified during the night with the contrast of the sky's darkness. It has been estimated that 83% of the world's people live under light-polluted skies and that 23% of the world's land area is affected by skyglow. The area affected by artificial illumination continues to increase. A major side effect of urbanization, light pollution is blamed for compromising health, disrupting ecosystems, and spoiling aesthetic environments. Studies show that ur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dome
A dome () is an architectural element similar to the hollow upper half of a sphere. There is significant overlap with the term cupola, which may also refer to a dome or a structure on top of a dome. The precise definition of a dome has been a matter of controversy and there are a wide variety of forms and specialized terms to describe them. A dome can rest directly upon a Rotunda (architecture), rotunda wall, a Tholobate, drum, or a system of squinches or pendentives used to accommodate the transition in shape from a rectangular or square space to the round or polygonal base of the dome. The dome's apex may be closed or may be open in the form of an Oculus (architecture), oculus, which may itself be covered with a roof lantern and cupola. Domes have a long architectural lineage that extends back into prehistory. Domes were built in ancient Mesopotamia, and they have been found in Persian architecture, Persian, Ancient Greek architecture, Hellenistic, Ancient Roman architecture, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical Telescope
An optical telescope gathers and focus (optics), focuses light mainly from the visible spectrum, visible part of the electromagnetic spectrum, to create a magnification, magnified image for direct visual inspection, to make a photograph, or to collect data through electronic image sensors. There are three primary types of optical telescope : * ''Refracting telescopes'', which use lens (optics), lenses and less commonly also Prism (optics), prisms (dioptrics) * ''Reflecting telescopes'', which use mirrors (catoptrics) * ''Catadioptric system#Catadioptric telescopes, Catadioptric telescopes'', which combine lenses and mirrors An optical telescope's ability to resolve small details is directly related to the diameter (or aperture) of its objective (optics), objective (the primary lens or mirror that collects and focuses the light), and its light-gathering power is related to the area of the objective. The larger the objective, the more light the telescope collects and the finer det ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electromagnetic Spectrum
The electromagnetic spectrum is the full range of electromagnetic radiation, organized by frequency or wavelength. The spectrum is divided into separate bands, with different names for the electromagnetic waves within each band. From low to high frequency these are: radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays. The electromagnetic waves in each of these bands have different characteristics, such as how they are produced, how they interact with matter, and their practical applications. Radio waves, at the low-frequency end of the spectrum, have the lowest photon energy and the longest wavelengths—thousands of kilometers, or more. They can be emitted and received by antenna (radio), antennas, and pass through the atmosphere, foliage, and most building materials. Gamma rays, at the high-frequency end of the spectrum, have the highest photon energies and the shortest wavelengths—much smaller than an atomic nucleus. Gamma rays, X-rays, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
