Zenith

The zenith is an imaginary point directly "above" a particular location, on the imaginary celestial sphere. "Above" means in the vertical direction opposite to the apparent gravitational force at that location. The opposite direction, i.e. the direction in which gravity pulls, is toward the nadir. The zenith is the "highest" point on the celestial sphere.

Zenith-Nadir-Horizon
Diagram showing the relationship between the zenith, the nadir, and different types of horizon. Note that the zenith is opposite the nadir.

Origin

The word "zenith" derives from an inaccurate reading of the Arabic expression سمت الرأس (samt ar-ra's), meaning "direction of the head" or "path above the head", by Medieval Latin scribes in the Middle Ages (during the 14th century), possibly through Old Spanish.[1] It was reduced to 'samt' ("direction") and miswritten as 'senit'/'cenit', the "m" being misread as "ni". Through the Old French 'cenith', 'zenith' first appeared in the 17th century.[2]

Relevance and use

Azimuth-Altitude schematic
Angles and planes of a celestial sphere
Tropical-area-mactan-philippines
The shadows of trees are the shortest on Earth when the Sun is directly overhead (at the zenith). This happens only at solar noon on certain days in the tropics, where the trees' latitude and the Sun's declination equal on certain days.

The term zenith is sometimes used to refer to the highest point, way, or level reached by a celestial body on its daily apparent path around a given point of observation.[3] This sense of the word is often used to describe the position of the Sun ("The sun reached its zenith..."), but to an astronomer, the Sun does not have its own zenith and is at the zenith only if it is directly overhead.

In a scientific context, the zenith is the direction of reference for measuring the zenith angle, the angle between a direction of interest (e.g. a star) and the local zenith.

The Sun reaches the observer's zenith when it is 90° above the horizon, and this only happens between the Tropic of Cancer and the Tropic of Capricorn.

At a given location during the course of a day, the Sun reaches not only its zenith but also its nadir, at the antipode of that location 12 hours from solar noon.

In astronomy, the altitude in the horizontal coordinate system and the zenith angle are complementary angles, with the horizon perpendicular to the zenith. The astronomical meridian is also determined by the zenith, and is defined as a circle on the celestial sphere that passes through the zenith, nadir, and the celestial poles.

A zenith telescope is a type of telescope designed to point straight up at or near the zenith, and used for precision measurement of star positions, to simplify telescope construction, or both. The NASA Orbital Debris Observatory and the Large Zenith Telescope are both zenith telescopes since the use of liquid mirrors meant these telescopes could only point straight up.

On the International Space Station, zenith and nadir are used instead of up and down, referring to directions within and around the station, relative to the earth.

See also

References

  1. ^ Corominas, J. (1987). Breve diccionario etimológico de la lengua castellana (3rd ed.). Madrid. p. 144. ISBN 978-8-42492-364-8.
  2. ^ "Zenith". Dictionary.com. Retrieved March 21, 2012.
  3. ^ "Zenith". Merriam-Webster. Retrieved March 21, 2012.
  • Glickman, Todd S. (2000). Glossary of meteorology. American Meteorological Society. ISBN 978-1-878220-34-9.
  • McIntosh, D. H. (1972). Meteorological Glossary (5th ed.). ISBN 978-0-8206-0228-8.
  • Jacqueline Picoche (2002). Dictionnaire étymologique du français. Paris: Le Robert. ISBN 978-2-85036-458-7.CS1 maint: Multiple names: authors list (link)
Aspria Tennis Cup

The Aspria Tennis Cup (formerly Zenith Tennis Cup and Aspria Tennis Cup) is a professional tennis tournament played on outdoor red clay courts. It is currently part of the Association of Tennis Professionals (ATP) Challenger Tour. It is held annually at the Harbour Club Milano in Milan, Italy, since 2006.

Full Members' Cup

The Full Members' Cup was an association football cup competition held in English football from 1985 to 1992. It was also known under its sponsored names of the Simod Cup from 1987 to 1989 and the Zenith Data Systems Cup from 1989 to 1992.The competition was created after the 1985 Heysel Stadium disaster, when English clubs were banned from European competition, as an additional competition for clubs in the top two English League divisions. The competition's name refers to the clubs that were Full Members of the Football League, with full voting rights; teams from the lower two divisions were Associate Members and were only eligible for the Associate Members' Cup (now known as the EFL Trophy). The initial Full Members' Cup did not include the six teams that had qualified for 1985–86 European competitions, as these played in the English Super Cup instead.While the European ban of English clubs was partially lifted for 1990–91, and fully lifted for 1991–92, the Full Members' Cup survived through the end of 1991–92, its seventh season. The competition was then cancelled the following season when the old Football League First Division was replaced by the Premier League.

Seven finals took place between 1986 and 1992. Blackburn Rovers and Reading were the only Second Division teams to win the Cup.

Chelsea and Nottingham Forest were the most successful teams in the competition, with both of them winning it twice.

HMS Zenith (R95)

HMS Zenith was a Z-class destroyer of the Royal Navy built as by William Denny and Brothers, Dunbarton. She was ordered as part of the 10th Emergency Flotilla, and was originally to have been named HMS Wessex. She spent her first ten years in Royal Navy service, before being sold to the Egyptian Navy, which operated her as El Fateh. She was a training ship until 2014, and her name was transferred to a new vessel in 2017, but she remains listed by the IISS.

Haeundae Doosan We've the Zenith

Haeundae Doosan We've the Zenith is a complex of three residential towers in the Haeundae District of Busan, South Korea, which was completed in 2011. With 80 floors and a height of 301 m, Tower A is the 13th tallest residential building in the world, and has been officially announced as the second tallest building in Korea, according to the Ministry of Land, Transport and Maritime Affairs.

The Haeundae Doosan We’ve the Zenith consists of three residential buildings, with 70, 75 and 80 stories respectively, comprising 1,788 households in total, and one office building on its 42,500 square metres (457,000 sq ft) site. The total construction work took 48 months from November 2007 to November 2011.

Le Zénith

Le Zénith is the name given to a series of indoor arenas in France. The first arena, the "Zénith Paris" is a rejuvenation of the Pavillon de Paris. In French culture, the word "zénith" has become synonymous with "theater". A zénith is a theater that can accommodate concert tours, variety shows, plays, musicals and dance recitals. All zeniths carry a similar internal design of an indoor amphitheater that can seat at least 3,000 spectators.

A venue was planned to open in Saint-Denis, Réunion entitled Zénith du Port. The arena was proposed in 2005 by the city council. Planned to open in 2008 with a capacity of 6,000, the construction of the arena was shut down. It was determined the venue would not be profitable as there was no research done to see which events the arena could house. They also felt the venue would be a hard sell to bring in international talent. Kabardock was built on the proposed site of the zenith.

List of aircraft (Z)

This is a list of aircraft in alphabetical order beginning with 'Z'.

List of tallest buildings in South Korea

This list of tallest buildings in South Korea ranks skyscrapers in South Korea by height. The tallest building in South Korea is currently the 123–story Lotte World Tower, which rises 555 metres (1,821 ft) and was completed in 22 December 2016. It is also the world's 5th tallest building. There are currently three buildings over 300m under construction in South Korea. The three-building complex Haeundae LCT The Sharp in also under construction in Busan, and will reach 412 metres (1,352 ft). There are various other projects planned over 300 meters, including the 338 metres (1,109 ft) tall Parc1, scheduled to be completed in 2020, the 510 metres (1,673 ft) tall Busan Lotte Tower currently on hold, as well as the 569 metres (1,867 ft) tall Hyundai Global Business Center, which will break ground in 2019.

Obverse Books

Obverse Books is a British publisher initially known for publishing books relating to the character Iris Wildthyme, and currently for the Black Archive series of critical books on Doctor Who. The company also owns publishing rights for stories based on Faction Paradox and Sexton Blake and had an e-book only imprint named Manleigh Books between 2012 and 2016.

Quasi-Zenith Satellite System

The Quasi-Zenith Satellite System (QZSS) (準天頂衛星システム, Juntencho eisei shisutemu) is a project of the Japanese government for the development of a four-satellite regional time transfer system and a satellite-based augmentation system for the United States operated Global Positioning System (GPS) to be receivable in the Asia-Oceania regions, with a focus on Japan. The goal of QZSS is to provide highly precise and stable positioning services in the Asia-Oceania region, compatible with GPS. Four-satellite QZSS services (QZS-4) are available on a trial basis as of January 12, 2018, and officially started on November 1, 2018.

Spherical coordinate system

In mathematics, a spherical coordinate system is a coordinate system for three-dimensional space where the position of a point is specified by three numbers: the radial distance of that point from a fixed origin, its polar angle measured from a fixed zenith direction, and the azimuth angle of its orthogonal projection on a reference plane that passes through the origin and is orthogonal to the zenith, measured from a fixed reference direction on that plane. It can be seen as the three-dimensional version of the polar coordinate system.

The radial distance is also called the radius or radial coordinate. The polar angle may be called colatitude, zenith angle, normal angle, or inclination angle.

The use of symbols and the order of the coordinates differs between sources. In one system frequently encountered in physics (r, θ, φ) gives the radial distance, polar angle, and azimuthal angle, whereas in another system used in many mathematics books (r, θ, φ) gives the radial distance, azimuthal angle, and polar angle. In both systems ρ is often used instead of r. Other conventions are also used, so great care needs to be taken to check which one is being used.

A number of different spherical coordinate systems following other conventions are used outside mathematics. In a geographical coordinate system positions are measured in latitude, longitude and height or altitude. There are a number of different celestial coordinate systems based on different fundamental planes and with different terms for the various coordinates. The spherical coordinate systems used in mathematics normally use radians rather than degrees and measure the azimuthal angle counterclockwise from the x-axis to the y-axis rather than clockwise from north (0°) to east (+90°) like the horizontal coordinate system. The polar angle is often replaced by the elevation angle measured from the reference plane. Elevation angle of zero is at the horizon.

The spherical coordinate system generalizes the two-dimensional polar coordinate system. It can also be extended to higher-dimensional spaces and is then referred to as a hyperspherical coordinate system.

Streamline (comics)

Streamline is a British Golden Age superhero comic, which appeared in the short-lived magazine Streamline Comics (1947), which only ran for four issues. The character was co-created by Denis Gifford and Bob Monkhouse, and later appeared as a character in the 2000 AD strip Zenith and the independent title Black Tower Comics Group Adventures.

Summit

A summit is a point on a surface that is higher in elevation than all points immediately adjacent to it. The topographic terms acme, apex, peak (mountain peak), and zenith are synonymous.

The term top (mountain top) is generally used only for a mountain peak that is located at some distance from the nearest point of higher elevation. For example, a big massive rock next to the main summit of a mountain is not considered a summit. Summits near a higher peak, with some prominence or isolation, but not reaching a certain cutoff value for the quantities, are often considered subsummits (or subpeaks) of the higher peak, and are considered part of the same mountain. A pyramidal peak is an exaggerated form produced by ice erosion of a mountain top. Summit may also refer to the highest point along a line, trail, or route.

The highest summit in the world is Everest with height of 8844.43 m above sea level (29,029 ft). The first official ascent was made by Tenzing Norgay and Sir Edmund Hillary. They reached the mountain`s peak in 1953.Whether a highest point is classified as a summit, a sub peak or a separate mountain is subjective. The UIAA definition of a peak is that it has a prominence of 30 metres (98 ft) or more; it is a mountain summit if it has a prominence of at least 300 metres (980 ft). Otherwise, it's a subpeak.

In many parts of the western United States, the term summit refers to the highest point along a road, highway, or railroad. For example, the highest point along Interstate 80 in California is referred to as Donner Summit and the highest point on Interstate 5 is Siskiyou Mountain Summit.

The Quarto Group

The Quarto Group (LSE: QRT) is a global illustrated book publishing group founded in 1976. It is domiciled in the United States and listed on the London Stock Exchange.

Quarto sells books across 50 countries and in 39 languages through a variety of traditional and non-traditional channels. Quarto employs over 400 people in 11 offices in London, Brighton, Bristol, New York City, Minneapolis, Boston, Seattle, California, Hong Kong and Sydney.

The group was established by co-founders Laurence Orbach and Robert Morley and was listed on the London Stock Exchange in 1986. Laurence Orbach was Chairman and CEO until November 2012, when he was replaced as Chairman by Tim Chadwick and Marcus Leaver as CEO.

Zee Cine Awards

The Zee Cine Award (ZCA) is an awards ceremony for the Hindi film industry. They were instituted in November 1997 to award "Excellence in cinema - the democratic way".They were first held in Mumbai until 2004, when the ZCA went international and had their ceremony in Dubai, and in following years in London, Mauritius, Malaysia, and London again in 2008. It was not held in 2009 and 2010, but resumed in 2011, being held in Singapore in 2012 it was held at the CotaiArena in Macao.The 2018 edition was held at MMRDA Grounds, Mumbai.

Zenith (building)

The Kulturhalle Zenith (also known as the Zenith Halle or simply Zenith) is an events hall located in the Schwabing-Freimann borough of Munich, Germany. Originally opening in 1918 as a part of a railway repair shop, the hall was converted into performance venue in 1994. Since its opening in August 1996, it has hosted concerts, fairs, company presentations and parties

Zenith (comics)

Zenith was a story about a British superhero, which appeared in the British science fiction comic 2000 AD. Created by writer Grant Morrison and artist Steve Yeowell, with original character designs by Brendan McCarthy, it first appeared in 2000 AD #535 (22 August 1987). The character Zenith (real name Robert McDowell) first appeared in the second episode – the first episode set the backdrop for his introduction.

Shallow and sarcastic, Zenith was a distinctly Generation X superhero. Morrison used the Zenith serial to explore cultural differences between generations and criticise the Conservative Party.Zenith was featured regularly in 2000 AD from 1987 until 1992, with occasional appearances since. The series was an early success for Morrison, who has since written popular works for DC and Marvel, using his own characters. The first series won the 1987 Eagle Award for Favourite Single or Continuing Story.

Zenith Electronics

Zenith Electronics, LLC is a research and development company that develops ATSC and digital rights management technologies. It is owned by the South Korean company LG Electronics. Zenith was previously an American brand of consumer electronics. It originally was a manufacturer of radio and television receivers and other consumer electronics, and was headquartered in Glenview, Illinois. After a series of layoffs, the consolidated headquarters moved to Lincolnshire, Illinois. For many years, their famous slogan was "The quality goes in before the name goes on." (This slogan was borrowed from the "CROWN" Piano made by Geo. P Bent of Chicago) LG Electronics acquired a controlling share of Zenith in 1995; Zenith became a wholly owned subsidiary in 1999. Zenith was the inventor of subscription television and the modern remote control, and the first to develop High-definition television (HDTV) in North America.Zenith-branded products were sold in North America, Germany, Thailand (to 1983), Cambodia, Laos, Vietnam, India, and Myanmar.

Zenith Glacier

Zenith Glacier (71°52′S 163°45′E) is a glacier which lies 1 mile (1.6 km) west of Johnstone Glacier and drains south from the south end of Lanterman Range, Bowers Mountains. So named by the New Zealand Geological Survey Antarctic Expedition (NZGSAE) to northern Victoria Land, 1967–68, because the glacier is an important geological outcrop area with an impressive view from the top (the head of the glacier) of much of the Bowers Mountains.

This article incorporates public domain material from the United States Geological Survey document "Zenith Glacier" (content from the Geographic Names Information System).

Zénith Paris

Zénith Paris (originally known as Zénith de Paris and commonly referred to as Le Zénith) is a multi-purpose indoor arena in Paris, France. It is located in the Parc de la Villette in the 19th arrondissement on the edge of the Canal de l'Ourcq. Its ability to seat up to 6,293 people makes it one of the largest venues in Paris. The closest métro and RER stations are Porte de la Villette, Porte de Pantin, and Pantin.

It is the first venue to bear the moniker of Zénith; a theatre located in France with a minimum capacity of 3,000. Because of this, the venue in Paris simply referred to as "Le Zénith" in many forms of media.

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