105 relations: African Plate, Airy-0, Almanac, Amerigo Vespucci, Analemma, Angle, Astrolabe, Bowditch's American Practical Navigator, Cardinal direction, Cartesian coordinate system, Cartography, Celestial sphere, Classification of discontinuities, Clockmaker, Coordinated Universal Time, Copenhagen, Degree (angle), East, Ecliptic, Ecliptic coordinate system, El Hierro, Ellipsoid, England, Equation of time, European Terrestrial Reference System 1989, Exploration, Galileo Galilei, Gas giant, Geodesic, Geodesy, Geodetic datum, Geographic coordinate system, Geographical distance, Geographical mile, Geographical pole, Geotagging, Great Britain, Great-circle distance, Greek alphabet, History of longitude, Horizontal position representation, Impact crater, International Meridian Conference, Invariable plane, Io (moon), Jerusalem, John Harrison, Lambda, Latitude, Libration, ..., List of population centers by longitude, Longitude Act, Lunar distance (navigation), Magnetic field, Map projection, Marine chronometer, Mars, Mercury (planet), Meridian arc, Mimas (moon), Minute and second of arc, Natural Area Code, Navigation, New World, North American Datum, North Pole, Northern Hemisphere, Orbital period, Orbital plane (astronomy), Orders of magnitude (length), Paris, Philadelphia, Pi, Pisa, Planet, Plate tectonics, Prime meridian, Quadrant (instrument), Radian, Retrograde and prograde motion, Right ascension, Rome, Rotation around a fixed axis, Royal Observatory, Greenwich, Sailor, Saint Petersburg, Sexagesimal, Singularity (mathematics), South American Plate, South Pole, Spheroid, Sun, The Island of the Day Before, Tidal locking, Time zone, Trigonometric functions, United States Geological Survey, Universal Time, Viking 2, Washington, D.C., West, Western Hemisphere, Wireless telegraphy, World Geodetic System, 180th meridian. Expand index (55 more) » « Shrink index
The African Plate is a major tectonic plate straddling the equator as well as the prime meridian.
Airy-0 is a crater on Mars whose location defined the position of the prime meridian of that planet.
An almanac (also spelled almanack and almanach) is an annual publication listing a set of events forthcoming in the next year.
Amerigo Vespucci (March 9, 1454February 22, 1512) was an Italian explorer, financier, navigator and cartographer.
In astronomy, an analemma (from Greek ἀνάλημμα analēmma "support") is a diagram showing the variation of the position of the Sun in the sky over the course of a year, as viewed at a fixed time of day and from a fixed location on the Earth.
In plane geometry, an angle is the figure formed by two rays, called the sides of the angle, sharing a common endpoint, called the vertex of the angle.
An astrolabe (ἀστρολάβος astrolabos; ٱلأَسْطُرلاب al-Asturlāb; اَختِرِیاب Akhteriab) is an elaborate inclinometer, historically used by astronomers and navigators to measure the inclined position in the sky of a celestial body, day or night.
The American Practical Navigator (colloquially often referred to as Bowditch), originally written by Nathaniel Bowditch, is an encyclopedia of navigation.
The four cardinal directions or cardinal points are the directions north, east, south, and west, commonly denoted by their initials N, E, S, and W. East and west are at right angles to north and south, with east being in the clockwise direction of rotation from north and west being directly opposite east.
A Cartesian coordinate system is a coordinate system that specifies each point uniquely in a plane by a pair of numerical coordinates, which are the signed distances to the point from two fixed perpendicular directed lines, measured in the same unit of length.
Cartography (from Greek χάρτης chartēs, "papyrus, sheet of paper, map"; and γράφειν graphein, "write") is the study and practice of making maps.
In astronomy and navigation, the celestial sphere is an abstract sphere with an arbitrarily large radius concentric to Earth.
Continuous functions are of utmost importance in mathematics, functions and applications.
A clockmaker is an artisan who makes and/or repairs clocks.
Copenhagen (København; Hafnia) is the capital and most populous city of Denmark.
A degree (in full, a degree of arc, arc degree, or arcdegree), usually denoted by ° (the degree symbol), is a measurement of a plane angle, defined so that a full rotation is 360 degrees.
East is one of the four cardinal directions or points of the compass.
The ecliptic is the circular path on the celestial sphere that the Sun follows over the course of a year; it is the basis of the ecliptic coordinate system.
The ecliptic coordinate system is a celestial coordinate system commonly used for representing the apparent positions and orbits of Solar System objects.
El Hierro, nicknamed Isla del Meridiano (the "Meridian Island"), is the smallest and farthest south and west of the Canary Islands (an Autonomous Community of Spain), in the Atlantic Ocean off the coast of Africa, with a population of 10,162 (2003).
An ellipsoid is a surface that may be obtained from a sphere by deforming it by means of directional scalings, or more generally, of an affine transformation.
England is a country that is part of the United Kingdom.
The equation of time describes the discrepancy between two kinds of solar time.
The European Terrestrial Reference System 1989 (ETRS89) is an ECEF (Earth-Centered, Earth-Fixed) geodetic Cartesian reference frame, in which the Eurasian Plate as a whole is static.
Exploration is the act of searching for the purpose of discovery of information or resources.
Galileo Galilei (15 February 1564Drake (1978, p. 1). The date of Galileo's birth is given according to the Julian calendar, which was then in force throughout Christendom. In 1582 it was replaced in Italy and several other Catholic countries with the Gregorian calendar. Unless otherwise indicated, dates in this article are given according to the Gregorian calendar. – 8 January 1642) was an Italian polymath.
A gas giant is a giant planet composed mainly of hydrogen and helium.
In differential geometry, a geodesic is a generalization of the notion of a "straight line" to "curved spaces".
Geodesy, also known as geodetics, is the earth science of accurately measuring and understanding three of Earth's fundamental properties: its geometric shape, orientation in space, and gravitational field.
A geodetic datum or geodetic system is a coordinate system, and a set of reference points, used to locate places on the Earth (or similar objects).
A geographic coordinate system is a coordinate system used in geography that enables every location on Earth to be specified by a set of numbers, letters or symbols.
Geographical distance is the distance measured along the surface of the earth.
The geographical mile is a unit of length determined by 1 minute of arc along the Earth's equator.
A geographical pole is either of the two points on a rotating body (planet, dwarf planet, natural satellite, sphere...etc) where its axis of rotation intersects its surface.
Geotagging or GeoTagging, is the process of adding geographical identification metadata to various media such as a geotagged photograph or video, websites, SMS messages, QR Codes or RSS feeds and is a form of geospatial metadata.
Great Britain, also known as Britain, is a large island in the north Atlantic Ocean off the northwest coast of continental Europe.
The great-circle distance or orthodromic distance is the shortest distance between two points on the surface of a sphere, measured along the surface of the sphere (as opposed to a straight line through the sphere's interior).
The Greek alphabet has been used to write the Greek language since the late 9th or early 8th century BC.
The history of longitude is a record of the effort, by astronomers, cartographers and navigators over several centuries, to discover a means of determining longitude.
A position representation is the parameters used to express a position relative to a reference.
An impact crater is an approximately circular depression in the surface of a planet, moon, or other solid body in the Solar System or elsewhere, formed by the hypervelocity impact of a smaller body.
The International Meridian Conference was a conference held in October 1884 in Washington, D.C., in the United States, to determine a prime meridian for international use.
The invariable plane of a planetary system, also called Laplace's invariable plane, is the plane passing through its barycenter (center of mass) perpendicular to its angular momentum vector.
Io (Jupiter I) is the innermost of the four Galilean moons of the planet Jupiter.
Jerusalem (יְרוּשָׁלַיִם; القُدس) is a city in the Middle East, located on a plateau in the Judaean Mountains between the Mediterranean and the Dead Sea.
John Harrison (– 24 March 1776) was a self-educated English carpenter and clockmaker who invented a marine chronometer, a long-sought-after device for solving the problem of calculating longitude while at sea.
Lambda, Λ, λ (uppercase Λ, lowercase λ; λάμ(β)δα lám(b)da) is the 11th letter of the Greek alphabet.
In geography, latitude is a geographic coordinate that specifies the north–south position of a point on the Earth's surface.
In astronomy, libration is a perceived oscillating motion of orbiting bodies relative to each other, notably including the motion of the Moon relative to Earth, or of trojan asteroids relative to planets.
The following is a list of cities by longitude.
The Longitude Act was an Act of Parliament of the United Kingdom passed in July 1714 at the end of the reign of Queen Anne.
In celestial navigation, lunar distance is the angular distance between the Moon and another celestial body.
A magnetic field is a vector field that describes the magnetic influence of electrical currents and magnetized materials.
A map projection is a systematic transformation of the latitudes and longitudes of locations from the surface of a sphere or an ellipsoid into locations on a plane.
A marine chronometer is a timepiece that is precise and accurate enough to be used as a portable time standard; it can therefore be used to determine longitude by means of celestial navigation.
Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System after Mercury.
Mercury is the smallest and innermost planet in the Solar System.
In geodesy, a meridian arc measurement is the distance between two points with the same longitude, i.e., a segment of a meridian curve or its length.
Mimas, also designated Saturn I, is a moon of Saturn which was discovered in 1789 by William Herschel.
A minute of arc, arcminute (arcmin), arc minute, or minute arc is a unit of angular measurement equal to of one degree.
The Natural Area Code (or Universal Address) is a proprietary geocode system for identifying an area anywhere on the Earth, or a volume of space anywhere around the Earth.
Navigation is a field of study that focuses on the process of monitoring and controlling the movement of a craft or vehicle from one place to another.
The New World is one of the names used for the majority of Earth's Western Hemisphere, specifically the Americas (including nearby islands such as those of the Caribbean and Bermuda).
The North American Datum (NAD) is the datum now used to define the geodetic network in North America.
The North Pole, also known as the Geographic North Pole or Terrestrial North Pole, is (subject to the caveats explained below) defined as the point in the Northern Hemisphere where the Earth's axis of rotation meets its surface.
The Northern Hemisphere is the half of Earth that is north of the Equator.
The orbital period is the time a given astronomical object takes to complete one orbit around another object, and applies in astronomy usually to planets or asteroids orbiting the Sun, moons orbiting planets, exoplanets orbiting other stars, or binary stars.
The orbital plane of a revolving body is the geometric plane on which its orbit lies.
The following are examples of orders of magnitude for different lengths.
Paris is the capital and most populous city of France, with an area of and a population of 2,206,488.
Philadelphia is the largest city in the U.S. state and Commonwealth of Pennsylvania, and the sixth-most populous U.S. city, with a 2017 census-estimated population of 1,580,863.
The number is a mathematical constant.
Pisa is a city in the Tuscany region of Central Italy straddling the Arno just before it empties into the Ligurian Sea.
A planet is an astronomical body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and has cleared its neighbouring region of planetesimals.
Plate tectonics (from the Late Latin tectonicus, from the τεκτονικός "pertaining to building") is a scientific theory describing the large-scale motion of seven large plates and the movements of a larger number of smaller plates of the Earth's lithosphere, since tectonic processes began on Earth between 3 and 3.5 billion years ago.
A prime meridian is a meridian (a line of longitude) in a geographic coordinate system at which longitude is defined to be 0°.
A quadrant is an instrument that is used to measure angles up to 90°.
The radian (SI symbol rad) is the SI unit for measuring angles, and is the standard unit of angular measure used in many areas of mathematics.
Retrograde motion in astronomy is, in general, orbital or rotational motion of an object in the direction opposite the rotation of its primary, that is the central object (right figure).
Right ascension (abbreviated RA; symbol) is the angular distance measured only eastward along the celestial equator from the Sun at the March equinox to the (hour circle of the) point above the earth in question.
Rome (Roma; Roma) is the capital city of Italy and a special comune (named Comune di Roma Capitale).
Rotation around a fixed axis or about a fixed axis of revolution or motion with respect to a fixed axis of rotation is a special case of rotational motion.
The Royal Observatory, Greenwich (ROG; known as the Old Royal Observatory from 1957 to 1998, when the working Royal Greenwich Observatory, RGO, moved from Greenwich to Herstmonceux) is an observatory situated on a hill in Greenwich Park, overlooking the River Thames.
A sailor, seaman, mariner, or seafarer is a person who navigates waterborne vessels or assists as a crewmember in their operation and maintenance.
Saint Petersburg (p) is Russia's second-largest city after Moscow, with 5 million inhabitants in 2012, part of the Saint Petersburg agglomeration with a population of 6.2 million (2015).
Sexagesimal (base 60) is a numeral system with sixty as its base.
In mathematics, a singularity is in general a point at which a given mathematical object is not defined, or a point of an exceptional set where it fails to be well-behaved in some particular way, such as differentiability.
The South American Plate is a tectonic plate which includes the continent of South America and also a sizeable region of the Atlantic Ocean seabed extending eastward to the African Plate creating the Mid-Atlantic Ridge The easterly side is a divergent boundary with the African Plate forming the southern part of the Mid-Atlantic Ridge.
The South Pole, also known as the Geographic South Pole or Terrestrial South Pole, is one of the two points where the Earth's axis of rotation intersects its surface.
A spheroid, or ellipsoid of revolution, is a quadric surface obtained by rotating an ellipse about one of its principal axes; in other words, an ellipsoid with two equal semi-diameters.
The Sun is the star at the center of the Solar System.
The Island of the Day Before (L'isola del giorno prima) is a historical fiction novel by Umberto Eco set in the 17th-century during the historical search for the secret of longitude.
Tidal locking (also called gravitational locking or captured rotation) occurs when the long-term interaction between a pair of co-orbiting astronomical bodies drives the rotation rate of at least one of them into the state where there is no more net transfer of angular momentum between this body (e.g. a planet) and its orbit around the second body (e.g. a star); this condition of "no net transfer" must be satisfied over the course of one orbit around the second body.
A time zone is a region of the globe that observes a uniform standard time for legal, commercial, and social purposes.
In mathematics, the trigonometric functions (also called circular functions, angle functions or goniometric functions) are functions of an angle.
The United States Geological Survey (USGS, formerly simply Geological Survey) is a scientific agency of the United States government.
Universal Time (UT) is a time standard based on Earth's rotation.
The Viking 2 mission was part of the American Viking program to Mars, and consisted of an orbiter and a lander essentially identical to that of the Viking 1 mission.
Washington, D.C., formally the District of Columbia and commonly referred to as Washington or D.C., is the capital of the United States of America.
West is one of the four cardinal directions or points of the compass.
The Western Hemisphere is a geographical term for the half of Earth which lies west of the prime meridian (which crosses Greenwich, London, United Kingdom) and east of the antimeridian.
Wireless telegraphy is the transmission of telegraphy signals from one point to another by means of an electromagnetic, electrostatic or magnetic field, or by electrical current through the earth or water.
The World Geodetic System (WGS) is a standard for use in cartography, geodesy, and satellite navigation including GPS.
The 180th meridian or antimeridian is the meridian 180° east or west of the Prime Meridian, with which it forms a great circle dividing the earth into the Western and Eastern Hemispheres.
East longitude, Length of a degree of longitude, Long., Longatude, Longditude, Longitude (planets), Longitudes, Longtitude, Ls (astronomy), Meridian of longitude, Meridians of longitude, Planetocentric longitude, West longitude, Zero Point of Longitude.