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History Of The Telescope
The history of the telescope can be traced to before the invention of the earliest known telescope, which appeared in 1608 in the Netherlands, when a patent was submitted by Hans Lippershey, an eyeglass maker. Although Lippershey did not receive his patent, news of the invention soon spread across Europe. The design of these early refracting telescopes consisted of a convex objective lens and a concave eyepiece. Galileo improved on this design the following year and applied it to astronomy. In 1611, Johannes Kepler described how a far more useful telescope could be made with a convex objective lens and a convex eyepiece lens. By 1655, astronomers such as Christiaan Huygens were building powerful but unwieldy Keplerian telescopes with compound eyepieces. Isaac Newton is credited with building the first reflector in 1668 with a design that incorporated a small flat diagonal mirror to reflect the light to an eyepiece mounted on the side of the telescope. Laurent Cassegrain in 16 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Emblemata 1624
Usually known simply as the ''Emblemata'', the first emblem book appeared in Augsburg (Germany) in 1531 under the title ''Viri Clarissimi D. Andreae Alciati Iurisconsultiss. Mediol. Ad D. Chonradum Peutingerum Augustanum, Iurisconsultum Emblematum Liber''. Produced by the publisher Heinrich Steyner, the unauthorized first print edition was compiled from a manuscript of Latin poems which the Italian jurist Andrea Alciato had dedicated to his friend Conrad Peutinger and circulated to his acquaintances. The 1531 edition was soon followed by a 1534 edition authorized by Alciato: published in Paris by Christian Wechel, this appeared under the title ''Andreae Alciati Emblematum Libellus'' ("''Andrea Alciato's Little Book of Emblems''"). The word "emblemata" is simply the plural of the Greek word "emblema", meaning a piece of inlay or mosaic, or an ornament: in his preface to Peutinger, Alciato describes his emblems as a learned recreation, a pastime for humanists steeped in classical c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paraboloid
In geometry, a paraboloid is a quadric surface that has exactly one axial symmetry, axis of symmetry and no central symmetry, center of symmetry. The term "paraboloid" is derived from parabola, which refers to a conic section that has a similar property of symmetry. Every plane section of a paraboloid made by a plane Parallel (geometry)#A line and a plane, parallel to the axis of symmetry is a parabola. The paraboloid is hyperbolic if every other plane section is either a hyperbola, or two crossing lines (in the case of a section by a tangent plane). The paraboloid is elliptic if every other nonempty plane section is either an ellipse, or a single point (in the case of a section by a tangent plane). A paraboloid is either elliptic or hyperbolic. Equivalently, a paraboloid may be defined as a quadric surface that is not a cylinder, and has an implicit surface, implicit equation whose part of degree two may be factored over the complex numbers into two different linear factors. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gemini Observatory
The Gemini Observatory comprises two 8.1-metre (26.6 ft) telescopes, Gemini North and Gemini South, situated in Hawaii and Chile, respectively. These twin telescopes offer extensive coverage of the northern and southern skies and rank among the most advanced optical/infrared astronomy, infrared telescopes available to astronomers. ''(See List of largest optical reflecting telescopes)''. The observatory is owned and operated by the National Science Foundation (NSF) of the United States, the National Research Council Canada, National Research Council of Canada, CONICYT of Chile, MCTI of Brazil, MCTIP of Argentina, and Korea Astronomy and Space Science Institute, Korea Astronomy and Space Science Institute (KASI) of Republic of Korea. The NSF is the primary funding contributor, providing about 70% of the required resources. The Association of Universities for Research in Astronomy (AURA) manages the operations and maintenance of the observatory through a cooperative agreement wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Very Large Telescope
The Very Large Telescope (VLT) is an astronomical facility operated since 1998 by the European Southern Observatory, located on Cerro Paranal in the Atacama Desert of northern Chile. It consists of four individual telescopes, each equipped with a primary mirror that measures in diameter. These optical telescopes, named ''Antu'', ''Kueyen'', ''Melipal'', and ''Yepun'' (all words for astronomical objects in the Mapuche language), are generally used separately but can be combined to achieve a very high angular resolution. The VLT array is also complemented by four movable Auxiliary Telescopes (ATs) with apertures. The VLT is capable of observing both visible and infrared wavelengths. Each individual telescope can detect objects that are roughly four billion times fainter than what can be seen with the naked eye. When all the telescopes are combined, the facility can achieve an angular resolution of approximately 0.002 arcsecond. In single telescope mode, the angular resol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Keck Telescopes
The W. M. Keck Observatory is an astronomical observatory with two telescopes at an elevation of 4,145 meters (13,600 ft) near the summit of Mauna Kea in the U.S. state of Hawaii. Both telescopes have aperture primary mirrors, and, when completed in 1993 (Keck I) and 1996 (Keck II), they were the largest optical reflecting telescopes in the world. They have been the third and fourth largest since 2006. Overview With a concept first proposed in 1977, telescope designers Terry Mast, of the University of California, Berkeley, and Jerry Nelson of Lawrence Berkeley Laboratory had been developing the technology necessary to build a large, ground-based telescope. In 1985, Howard B. Keck of the W. M. Keck Foundation gave $70 million to fund the construction of the Keck I telescope, which began in September 1985. First light occurred on November 24, 1990, using 9 of the eventual 36 segments. When construction of the first telescope was well advanced, further donations ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Active Optics
Active optics is a technology used with reflecting telescopes developed in the 1980s, which actively shapes a telescope's mirrors to prevent deformation due to external influences such as wind, temperature, and mechanical stress. Without active optics, the construction of 8 metre class telescopes is not possible, nor would telescopes with segmented mirrors be feasible. This method is used by, among others, the Nordic Optical Telescope, the New Technology Telescope, the Telescopio Nazionale Galileo and the Keck telescopes, as well as all of the largest telescopes built since the mid-1990s. Active optics is not to be confused with adaptive optics, which operates at a shorter timescale and corrects atmospheric distortions. In astronomy Most modern telescopes are reflectors, with the primary element being a very large mirror. Historically, primary mirrors were quite thick in order to maintain the correct surface figure in spite of forces tending to deform it, like wind and the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alt-azimuth Mount
An altazimuth mount or alt-azimuth mount is a simple two-axis mount for supporting and rotating an instrument about two perpendicular axes – one vertical and the other horizontal. Rotation about the vertical axis varies the azimuth (compass bearing) of the pointing direction of the instrument. Rotation about the horizontal axis varies the altitude angle (angle of elevation) of the pointing direction. These mounts are used, for example, with telescopes, cameras, radio antennas, heliostat mirrors, solar panels, and guns and similar weapons. Several names are given to this kind of mount, including altitude-azimuth, azimuth-elevation and various abbreviations thereof. A gun turret is essentially an alt-azimuth mount for a gun, and a standard camera tripod is an alt-azimuth mount as well. Astronomical telescope altazimuth mounts When used as an astronomical telescope mount, the biggest advantage of an alt-azimuth mount is the simplicity of its mechanical design. The primary disadv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hale Telescope
The Hale Telescope is a , 3.3 reflecting telescope at the Palomar Observatory in San Diego County, California, US, named after astronomer George Ellery Hale. With funding from the Rockefeller Foundation in 1928, he orchestrated the planning, design, and construction of the observatory, but with the project ending up taking 20 years he did not live to see its commissioning. The Hale was groundbreaking for its time, with double the diameter of the second-largest telescope, and pioneered many new technologies in telescope mount design and in the design and fabrication of its large aluminum coated "honeycomb" low thermal expansion Pyrex mirror. It was completed in 1949 and is still in active use. The Hale Telescope represented the technological limit in building large optical telescopes for over 30 years. It was the largest telescope in the world from its construction in 1949 until the Soviet BTA-6 was built in 1976, and the second largest until the construction of the Keck Ob ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hooker Telescope
The Mount Wilson Observatory (MWO) is an astronomical observatory in Los Angeles County, California, United States. The MWO is located on Mount Wilson, a peak in the San Gabriel Mountains near Pasadena, northeast of Los Angeles. The observatory contains two historically important telescopes: the Hooker telescope, which was the largest aperture telescope in the world from its completion in 1917 to 1949, and the 60-inch telescope which was the largest operational telescope in the world when it was completed in 1908. It also contains the Snow solar telescope completed in 1905, the solar tower completed in 1908, the solar tower completed in 1912, and the CHARA array, built by Georgia State University, which became fully operational in 2004 and was the largest optical interferometer in the world at its completion. Due to the inversion layer that traps warm air and smog over Los Angeles, Mount Wilson has steadier air than any other location in North America, making it ide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yerkes Observatory
Yerkes Observatory ( ) is an astronomical observatory located in Williams Bay, Wisconsin, United States. The observatory was operated by the University of Chicago Department of Astronomy and Astrophysics from its founding in 1897 until 2018. Ownership was transferred to the non-profit Yerkes Future Foundation (YFF) in May 2020, which began millions of dollars of restoration and renovation of the historic building and grounds. Yerkes re-opened for public tours and programming in May 2022. The observatory, often called "the birthplace of modern astrophysics", was founded in 1892 by astronomer George Ellery Hale and financed by businessman Charles T. Yerkes. It represented a shift in the thinking about observatories, from their being mere housing for telescopes and observers, to the early-20th-century concept of observation equipment integrated with laboratory space for physics and chemistry analysis. The observatory's main dome houses a 40-in aperture (102 cm) doublet len ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hubble Space Telescope
The Hubble Space Telescope (HST or Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the Orbiting Solar Observatory, first space telescope, but it is one of the largest and most versatile, renowned as a vital research tool and as a public relations boon for astronomy. The Hubble Space Telescope is named after astronomer Edwin Hubble and is one of NASA's Great Observatories program, Great Observatories. The Space Telescope Science Institute (STScI) selects Hubble's targets and processes the resulting data, while the Goddard Space Flight Center (GSFC) controls the spacecraft. Hubble features a mirror, and its five main instruments observe in the ultraviolet, visible spectrum, visible, and near-infrared regions of the electromagnetic spectrum. Hubble's orbit outside the distortion of atmosphere of Earth, Earth's atmosphere allows it to capture extremely high-resolution images with substantially lower background lig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cassegrain Reflector
The Cassegrain reflector is a combination of a primary concave mirror and a secondary convex mirror, often used in optical telescopes and Antenna (radio), radio antennas, the main characteristic being that the optical path folds back onto itself, relative to the optical system's primary mirror entrance aperture. This design puts the Focus (optics), focal point at a convenient location behind the primary mirror and the convex secondary adds a Telephoto lens, telephoto effect creating a much longer focal length in a mechanically short system. In a symmetrical Cassegrain both mirrors are aligned about the optical axis, and the primary mirror usually contains a hole in the center, thus permitting the light to reach an eyepiece, a camera, or an image sensor. Alternatively, as in many radio telescopes, the final focus may be in front of the primary. In an asymmetrical Cassegrain, the mirror(s) may be tilted to avoid obscuration of the primary or to avoid the need for a hole in the prima ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
