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The Sidereal Messenger
Goodsell Observatory is an observatory at Carleton College in Northfield, Minnesota, United States. It was constructed in 1887 and was, at the time, the largest observatory in the state of Minnesota. The Goodsell Observatory and its predecessor, a smaller observatory that opened in 1878, served as a widely consulted timekeeping station, bringing national prominence to Carleton College in the late 19th and early 20th centuries. Goodsell Observatory was listed on the National Register of Historic Places in 1975 for its national significance in the themes of architecture, communications, education, engineering, literature, and science. It was nominated for being one of the nation's few intact 19th-century observatories (complete with a large collection of vintage scientific equipment); and for its critical timekeeping service, its association with scientific literature (founder William W. Payne also founded the journal ''Popular Astronomy''), its fine Romanesque Revival architec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carleton College
Carleton College ( ) is a private liberal arts college in Northfield, Minnesota. Founded in 1866, it had 2,105 undergraduate students and 269 faculty members in fall 2016. The 200-acre main campus is between Northfield and the 800-acre Cowling Arboretum, which became part of the campus in the 1920s. Admissions is highly selective with an acceptance rate of 16.5% in 2022, and Carleton is annually ranked near the top in most rankings of liberal arts schools. Carleton is particularly renowned for its undergraduate teaching, having been ranked #1 in Undergraduate Teaching by U.S. News & World Report for over a decade. Students can choose courses from 33 major programs and 31 minor programs and have the option to design their own major. Carleton's varsity sports compete at the NCAA Division III level in the Minnesota Intercollegiate Athletic Conference. Carleton is also known for its Division 1 Ultimate Frisbee teams, which have won multiple national championships. Among liber ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Signal Corps (United States Army)
) , colors = Orange and white , colors_label = Corps colors , march = , mascot = , equipment = , equipment_label = , battles = , anniversaries = 21 June 1860 , decorations = , battle_honours = , notable_commanders = BG Albert J. Myer BG Adolphus Greely , identification_symbol = , identification_symbol_label = Branch insignia , identification_symbol_2 = , identification_symbol_2_label = Regimental insignia , current_commander = , current_commander_label = , ceremonial_chief = Colonel Paul D. Howard , ceremonial_chief_label = Chief of Signal , command_sergeant_major = CSM Darien D. Lawshea , command_sergeant_major_label = Sergeant Major of the Regiment The United States Army Signal Corps (U ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meteorite
A meteorite is a solid piece of debris from an object, such as a comet, asteroid, or meteoroid, that originates in outer space and survives its passage through the atmosphere to reach the surface of a planet or Natural satellite, moon. When the original object enters the atmosphere, various factors such as friction, pressure, and chemical interactions with the atmospheric gases cause it to heat up and radiate energy. It then becomes a meteor and forms a Meteoroid#Fireball, fireball, also known as a shooting star; astronomers call the brightest examples "Bolide#Astronomy, bolides". Once it settles on the larger body's surface, the meteor becomes a meteorite. Meteorites vary greatly in size. For geologists, a bolide is a meteorite large enough to create an impact crater. Meteorites that are recovered after being observed as they transit the atmosphere and Impact event, impact the Earth are called meteorite falls. All others are known as meteorite finds. Meteorites have traditiona ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Denver
The University of Denver (DU) is a private university, private research university in Denver, Colorado. Founded in 1864, it is the oldest independent private university in the Mountain States, Rocky Mountain Region of the United States. It is Carnegie Classification of Institutions of Higher Education, classified among "R1: Doctoral Universities – very high research activity". DU enrolls approximately 5,700 undergraduate students and 7,200 graduate students. The main campus is a designated arboretum and is located primarily in the Denver#Neighborhoods, University Neighborhood, about five miles (8 km) south of downtown Denver. The 720-acre Kennedy Mountain Campus is located approximately 110 miles northwest of Denver, in Larimer County. History In March 1864, John Evans (Colorado governor), John Evans, former List of Governors of Colorado#Governors of the Territory of Colorado, Governor of the Colorado Territory, appointee of President Abraham Lincoln, founded the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chamberlin Observatory
Chamberlin Observatory is an astronomical observatory owned and operated by the University of Denver. It is located in Denver, Colorado (US) in Observatory Park. It is named for Humphrey B. Chamberlin, a Denver real estate magnate who pledged $50,000 in 1888 to build and equip the facility. The observatory building was designed by Robert S. Roeschlaub, with the astronomical aspects and functions designed by Professor Herbert Alonzo Howe after he visited many observatories in the east. It was modeled after the Goodsell Observatory at Carleton College in Northfield, Minnesota, and constructed from rusticated red sandstone blocks. The Romanesque structure includes a central rotunda and domed roof. Construction began in 1890. The 20-inch objective lens for the observatory's main refracting telescope was made by Alvan Clark & Sons, and the mount was built by George Nicholas Saegmuller. The mount rests on a cast iron pillar which is in turn supported by a massive stone pier. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photometer
A photometer is an instrument that measures the strength of electromagnetic radiation in the range from ultraviolet to infrared and including the visible spectrum. Most photometers convert light into an electric current using a photoresistor, photodiode, or photomultiplier. Photometers measure: *Illuminance *Irradiance *Light absorption * Scattering of light *Reflection of light *Fluorescence *Phosphorescence *Luminescence History Before electronic light sensitive elements were developed, photometry was done by estimation by the eye. The relative luminous flux of a source was compared with a standard source. The photometer is placed such that the illuminance from the source being investigated is equal to the standard source, as the human eye can judge equal illuminance. The relative luminous fluxes can then be calculated as the illuminance decreases proportionally to the inverse square of distance. A standard example of such a photometer consists of a piece of paper with an o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photoelectric
The photoelectric effect is the emission of electrons when electromagnetic radiation, such as light, hits a material. Electrons emitted in this manner are called photoelectrons. The phenomenon is studied in condensed matter physics, and solid state and quantum chemistry to draw inferences about the properties of atoms, molecules and solids. The effect has found use in electronic devices specialized for light detection and precisely timed electron emission. The experimental results disagree with classical electromagnetism, which predicts that continuous light waves transfer energy to electrons, which would then be emitted when they accumulate enough energy. An alteration in the intensity of light would theoretically change the kinetic energy of the emitted electrons, with sufficiently dim light resulting in a delayed emission. The experimental results instead show that electrons are dislodged only when the light exceeds a certain frequency—regardless of the light's intensity or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sidereal Clock
Sidereal time (as a unit also sidereal day or sidereal rotation period) (sidereal ) is a timekeeping system that astronomers use to locate celestial objects. Using sidereal time, it is possible to easily point a telescope to the proper coordinates in the night sky. In short, sidereal time is a "time scale that is based on Earth's rate of rotation measured relative to the fixed stars", or more correctly, relative to the March equinox. Viewed from the same location, a star seen at one position in the sky will be seen at the same position on another night at the same sidereal time. This is similar to how the time kept by a sundial (Solar time) can be used to find the location of the Sun. Just as the Sun and Moon appear to rise in the east and set in the west due to the rotation of Earth, so do the stars. Both Solar time and sidereal time make use of the regularity of Earth's rotation about its polar axis: solar time following the Sun while, roughly speaking, sidereal time follo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Warner & Swasey Company
The Warner & Swasey Company was an American manufacturer of machine tools, instruments, and special machinery. It operated as an independent business firm, based in Cleveland, from its founding in 1880 until its acquisition in 1980. It was founded as a partnership in 1880 by Worcester Reed Warner (1846–1929) and Ambrose Swasey (1846–1937). The company was best known for two general types of products: astronomical telescopes and turret lathes. It also did a large amount of instrument work, such as equipment for astronomical observatories and military instruments (rangefinders, optical gunsights, etc.) The themes that united these various lines of business were the crafts of toolmaking and instrument-making, which have often overlapped technologically. In the decades after World War II, it also entered the heavy equipment industry with its acquisition of the Gradall brand. History In 1866, Swasey and Warner met as fellow apprentices at the Exeter Machine Works in Exeter, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
German Equatorial Mount
An equatorial mount is a mount for instruments that compensates for Earth's rotation by having one rotational axis, the polar axis, parallel to the Earth's axis of rotation. This type of mount is used for astronomical telescopes and cameras. The advantage of an equatorial mount lies in its ability to allow the instrument attached to it to stay fixed on any celestial object with diurnal motion by driving one axis at a constant speed. Such an arrangement is called a sidereal or clock drive. Equatorial mounts achieve this by aligning their rotational axis with the Earth, a process known as polar alignment. Astronomical telescope mounts In astronomical telescope mounts, the equatorial axis (the '' right ascension'') is paired with a second perpendicular axis of motion (known as the '' declination''). The equatorial axis of the mount is often equipped with a motorized "''clock drive''", that rotates that axis one revolution every 23 hours and 56 minutes in exact sync with the appar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Naval Observatory
United States Naval Observatory (USNO) is a scientific and military facility that produces geopositioning, navigation and timekeeping data for the United States Navy and the United States Department of Defense. Established in 1830 as the Depot of Charts and Instruments, it is one of the oldest scientific agencies in the United States, and remains the country's leading authority for astronomical and timing data for all purposes. The observatory is located in Northwest Washington, D.C. at the northwestern end of Embassy Row. It is among the few pre-20th century astronomical observatories located in an urban area; initially located in Foggy Bottom near the city's center, it was relocated to its current location in 1893 to escape light pollution. The USNO has conducted significant scientific studies throughout its history, including measuring the speed of light, observing solar eclipses, and discovering the moons of Mars. Its achievements including providing data for the first ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saint Paul, Minnesota
Saint Paul (abbreviated St. Paul) is the List of capitals in the United States, capital of the U.S. state of Minnesota and the county seat of Ramsey County, Minnesota, Ramsey County. Situated on high bluffs overlooking a bend in the Mississippi River, Saint Paul is a regional business hub and the center of Minnesota's government. The Minnesota State Capitol and the state government offices all sit on a hill close to the city's downtown district. One of the oldest cities in Minnesota, Saint Paul has several historic neighborhoods and landmarks, such as the Summit Avenue (St. Paul), Summit Avenue Neighborhood, the James J. Hill House, and the Cathedral of Saint Paul (Minnesota), Cathedral of Saint Paul. Like the adjacent and larger city of Minneapolis, Saint Paul is known for its cold, snowy winters and humid summers. As of the 2021 census estimates, the city's population was 307,193, making it the List of United States cities by population, 67th-largest city in the United State ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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