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Large Zenith Telescope
The Large Zenith Telescope (LZT) was a 6.0-meter diameter liquid-mirror telescope located in the University of British Columbia's Malcolm Knapp Research Forest, about east from Vancouver, British Columbia, Canada (north from Maple Ridge). It was one of the largest optical telescopes in the world, but still quite inexpensive. The telescope was completed in the spring of 2003 and decommissioned in 2016. Design While a zenith telescope has the disadvantage of not being able to look anywhere but at a small spot straight up, its simplified setup permits the use of a mirror consisting of a smoothly spinning pan filled with liquid mercury. Such a mirror can be made much larger than a conventional mirror, greatly increasing light collecting ability. The LZT is used for ''transit imaging'', meaning that Earth's rotation moves stars along the sensor, and the latent image in the sensor is moved electronically in step with this movement, so that it is read out at the trailing edge. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liquid-mirror Telescope
Liquid-mirror telescopes are telescopes with mirrors made with a reflective liquid. The most common liquid used is mercury, but other liquids will work as well (for example, low-melting alloys of gallium). The liquid and its container are rotated at a constant speed around a vertical axis, which causes the surface of the liquid to assume a paraboloidal shape. This parabolic reflector can serve as the primary mirror of a reflecting telescope. The rotating liquid assumes the same surface shape regardless of the container's shape; to reduce the amount of liquid metal needed, and thus weight, a rotating mercury mirror uses a container that is as close to the necessary parabolic shape as possible. Liquid mirrors can be a low-cost alternative to conventional large telescopes. Compared to a solid glass mirror that must be cast, ground, and polished, a rotating liquid-metal mirror is much less expensive to manufacture. Isaac Newton noted that the free surface of a rotating liquid forms a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Latent Image
{{citations needed, date=November 2015 A latent image is an invisible image produced by the exposure to light of a photosensitive material such as photographic film. When photographic film is developed, the area that was exposed darkens and forms a visible image. In the early days of photography, the nature of the invisible change in the silver halide crystals of the film's emulsion coating was unknown, so the image was said to be "latent" until the film was treated with photographic developer. In more physical terms, a latent image is a small cluster of metallic silver atoms formed in or on a silver halide crystal due to reduction of interstitial silver ions by photoelectrons (a photolytic silver cluster). If intense exposure continues, such photolytic silver clusters grow to visible sizes. This is called ''printing out'' the image. On the other hand, the formation of a visible image by the action of photographic developer is called ''developing out'' the image. The size of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lists Of Telescopes
This is a list of lists of telescopes. *List of astronomical interferometers at visible and infrared wavelengths *List of astronomical observatories *List of highest astronomical observatories *List of large optical telescopes *List of largest infrared telescopes *List of largest optical telescopes historically *List of largest optical telescopes in the 18th century *List of largest optical telescopes in the 19th century *List of largest optical telescopes in the 20th century *List of largest optical reflecting telescopes *List of largest optical refracting telescopes *List of optical telescopes *List of proposed space observatories *List of radio telescopes *List of solar telescopes *List of space telescopes *List of telescopes of Australia *List of largest optical telescopes in the British Isles *List of telescope parts and construction *List of telescope types *List of the largest optical telescopes in North America *List of X-ray space telescopes See also * Lists of astronaut ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of The Largest Optical Telescopes In North America ...
This is a list of the largest optical telescopes in North America. 21st century A list of optical telescopes located in North America by aperture. Refractors Some of the big traditional refractors (telescope with lens) in North America: Biggest telescopes in 1950 ''Optical telescopes only'' Biggest telescopes in 1900 Biggest telescopes in 1850 Some of the largest at observatories: See also *Lists of telescopes *List of radio telescopes *List of largest optical reflecting telescopes (mirrors) *List of largest optical refracting telescopes (lenses) References External linksUS Telescopes (1989) {{DEFAULTSORT:Largest optical telescopes in the United States Lists of telescopes Telescopes Optical telescopes An optical telescope is a telescope that gathers and focuses light mainly from the visible part of the electromagnetic spectrum, to create a magnified image for direct visual inspection, to make a photograph, or to collect data through electr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical Spectrometer
An optical spectrometer (spectrophotometer, spectrograph or spectroscope) is an instrument used to measure properties of light over a specific portion of the electromagnetic spectrum, typically used in spectroscopic analysis to identify materials. The variable measured is most often the light's Intensity (physics), intensity but could also, for instance, be the Polarization (waves), polarization state. The independent variable is usually the wavelength of the light or a unit directly proportional to the photon energy, such as Wavenumber, reciprocal centimeters or electron volts, which has a reciprocal relationship to wavelength. A spectrometer is used in spectroscopy for producing spectral lines and measuring their wavelengths and intensities. Spectrometers may operate over a wide range of non-optical wavelengths, from gamma rays and X-rays into the far infrared. If the instrument is designed to measure the spectrum on an absolute scale rather than a relative one, then it is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Science (journal)
''Science'', also widely referred to as ''Science Magazine'', is the peer-reviewed academic journal of the American Association for the Advancement of Science (AAAS) and one of the world's top academic journals. It was first published in 1880, is currently circulated weekly and has a subscriber base of around 130,000. Because institutional subscriptions and online access serve a larger audience, its estimated readership is over 400,000 people. ''Science'' is based in Washington, D.C., United States, with a second office in Cambridge, UK. Contents The major focus of the journal is publishing important original scientific research and research reviews, but ''Science'' also publishes science-related news, opinions on science policy and other matters of interest to scientists and others who are concerned with the wide implications of science and technology. Unlike most scientific journals, which focus on a specific field, ''Science'' and its rival ''Nature (journal), Nature'' c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atlas Obscura
''Atlas Obscura'' is an American-based online magazine and travel company. It was founded in 2009 by author Joshua Foer and documentary filmmaker/author Dylan Thuras. It catalogs unusual and obscure travel destinations via user-generated content. The articles on the website cover a number of topics including history, science, food, and obscure places. History Thuras and Foer met in 2007, and soon discussed ideas for a different kind of atlas, featuring places not commonly found in guidebooks. They hired a web designer in 2008 and launched ''Atlas Obscura'' in 2009. Sommer Mathis (formerly of '' The Atlantic's'' CityLab) was the site's Editor in Chief from 2017 to 2020. She was succeeded by Samir Patel, formerly of ''Archaeology'' magazine, who became the site's Editorial Director in 2020 and Editor in Chief in 2021. David Plotz remained as the site's CEO for five years (October 2014 — November 2019). Warren Webster, former president and CEO of digital publisher ''Coveteur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NASA Orbital Debris Observatory
NASA Orbital Debris Observatory (NODO) was an astronomical observatory located in the Lincoln National Forest near Cloudcroft, New Mexico approximately northeast of Alamogordo. From 1995 to 2002 it hosted two telescopes funded and operated by NASA that were dedicated to detecting orbital debris. The facility was initially called the Cloudcroft Electro-Optical Research Facility when it was completed in 1962, and was also known as the Cloudcroft Observatory. It is now privately owned by Embry-Riddle University. Telescopes * The NASA-LMT was a aperture liquid-mirror telescope located in NODO's main dome. It consisted of a 3 m diameter parabolic dish that held of a highly reflective liquid metal, mercury, spinning at a rate of 10 rpm, with sensors mounted above on a fixed structure. Due to the primary mirror's material, the NASA-LMT was configured as a zenith telescope. Using 20 narrowband filters, it cataloged space debris in Earth's orbit. The telescope was initially ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mercury (element)
Mercury is a chemical element with the symbol Hg and atomic number 80. It is also known as quicksilver and was formerly named hydrargyrum ( ) from the Greek words, ''hydor'' (water) and ''argyros'' (silver). A heavy, silvery d-block A block of the periodic table is a set of elements unified by the atomic orbitals their valence electrons or vacancies lie in. The term appears to have been first used by Charles Janet. Each block is named after its characteristic orbital: s-blo ... element, mercury is the only metallic element that is known to be liquid at standard temperature and pressure; the only other element that is liquid under these conditions is the halogen bromine, though metals such as caesium, gallium, and rubidium melt just above room temperature. Mercury occurs in deposits throughout the world mostly as cinnabar (mercuric sulfide). The red pigment vermilion is obtained by Mill (grinding), grinding natural cinnabar or synthetic mercuric sulfide. Mercury is used in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of British Columbia
The University of British Columbia (UBC) is a public university, public research university with campuses near Vancouver and in Kelowna, British Columbia. Established in 1908, it is British Columbia's oldest university. The university ranks among the top three universities in Canada. With an annual research budget of $759million, UBC funds over 8,000 projects a year. The Vancouver campus is situated adjacent to the University Endowment Lands located about west of downtown Vancouver. UBC is home to TRIUMF, Canada's national laboratory for Particle physics, particle and nuclear physics, which houses the world's largest cyclotron. In addition to the Peter Wall Institute for Advanced Studies and Stuart Blusson Quantum Matter Institute, UBC and the Max Planck Society collectively established the first Max Planck Institute in North America, specializing in quantum materials. One of the largest research libraries in Canada, the UBC Library system has over 9.9million volumes among it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zenith Telescope
A zenith telescope is a type of telescope that is designed to point straight up at or near the zenith. They are used for precision measurement of star positions, to simplify telescope construction, or both. A classic zenith telescope, also known as a zenith sector employs a strong altazimuth mount, fitted with levelling screws. Extremely sensitive levels are attached and the telescope has an eyepiece fitted with a micrometer. They are used for the measurement of small differences of zenith distance, and used in the determination of astronomic latitude. Other types of zenith telescopes include the Monument to the Great Fire of London, which includes a central shaft meant for use as a zenith telescope. High-precision (and fixed building) zenith telescopes were also used until the early 1980s to track Earth's north pole position e.g. Earth's rotation axis position ( polar motion). Since then radio astronomical quasar measurements ( VLBI) have also measured Earth's rotation axi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Comparison Optical Telescope Primary Mirrors
Comparison or comparing is the act of evaluating two or more things by determining the relevant, comparable characteristics of each thing, and then determining which characteristics of each are similar to the other, which are different, and to what degree. Where characteristics are different, the differences may then be evaluated to determine which thing is best suited for a particular purpose. The description of similarities and differences found between the two things is also called a comparison. Comparison can take many distinct forms, varying by field: To compare things, they must have characteristics that are similar enough in relevant ways to merit comparison. If two things are too different to compare in a useful way, an attempt to compare them is colloquially referred to in English as "comparing apples and oranges." Comparison is widely used in society, in science and in the arts. General usage Comparison is a natural activity, which even animals engage in when deci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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