 | This article needs additional citations for verification .(December 2011) |
North is one of the four compass points or cardinal directions. It is the opposite of south and is perpendicular to east and west. North is a noun, adjective, or adverb indicating direction or geography.
The word north is related to the Old High German nord, [1] both descending from the Proto-Indo-European unit *ner-, meaning "left; below" as north is to left when facing the rising sun. [2] Similarly, the other cardinal directions are also related to the sun's position. [3] [4] [5]
The Latin word borealis comes from the Greek boreas "north wind, north", which, according to Ovid, was personified as the wind-god Boreas, the father of Calais and Zetes. Septentrionalis is from septentriones, "the seven plow oxen", a name of Ursa Major . The Greek ἀρκτικός (arktikós) is named for the same constellation, and is the source of the English word Arctic .
Other languages have other derivations. For example, in Lezgian, kefer can mean both "disbelief" and "north", since to the north of the Muslim Lezgian homeland there are areas formerly inhabited by non-Muslim Caucasian and Turkic peoples. In many languages of Mesoamerica, north also means "up". In Hungarian, the word for north is észak, which is derived from éjszaka ("night"), since above the Tropic of Cancer, the Sun never shines from the north, except inside the Arctic Circle during the summer midnight sun.
North is sometimes abbreviated as N.
By convention, the top or upward-facing side of a map is north.
To go north using a compass for navigation, set a bearing or azimuth of 0° or 360°. Traveling directly north traces a meridian line upwards.
North is specifically the direction that, in Western culture, is considered the fundamental direction:
Magnetic north is of interest because it is the direction indicated as north on a properly functioning (but uncorrected) magnetic compass. [7] The difference between it and true north is called the magnetic declination (or simply the declination where the context is clear). For many purposes and physical circumstances, the error in direction that results from ignoring the distinction is tolerable; in others a mental or instrument compensation, based on assumed knowledge of the applicable declination, can solve all the problems. But simple generalizations on the subject should be treated as unsound, and as likely to reflect popular misconceptions about terrestrial magnetism.
Maps intended for usage in orienteering by compass will clearly indicate the local declination for easy correction to true north. Maps may also indicate grid north, which is a navigational term referring to the direction northwards along the grid lines of a map projection.
The visible rotation of the night sky around the visible celestial pole provides a vivid metaphor of that direction corresponding to "up". Thus the choice of the north as corresponding to "up" in the northern hemisphere, or of south in that role in the southern, is, before worldwide communication, anything but an arbitrary one - at least for night-time astronomers. [8] (Note: the southern hemisphere lacks a prominent visible analog to the northern Pole Star.) On the contrary, Chinese and Islamic cultures considered south as the proper "top" end for maps. [9] In the cultures of Polynesia, where navigation played an important role, winds - prevailing local or ancestral - can define cardinal points. [10]
In Western culture:
North is quite often associated with colder climates because most of the world's populated land at high latitudes is located in the Northern Hemisphere. The Arctic Circle passes through the Arctic Ocean, Norway, Sweden, Finland, Russia, the United States (Alaska), Canada (Yukon, Northwest Territories and Nunavut), Denmark (Greenland) and Iceland.
While the choice of north over south as prime direction reflects quite arbitrary historical factors,[ which? ] east and west are not nearly as natural alternatives as first glance might suggest. Their folk definitions are, respectively, "where the sun rises" and "where it sets". Except on the Equator, however, these definitions, taken together, would imply that
Reasonably accurate folk astronomy, such as is usually attributed to Stone Age peoples or later Celts, would arrive at east and west by noting the directions of rising and setting (preferably more than once each) and choosing as prime direction one of the two mutually opposite directions that lie halfway between those two. The true folk-astronomical definitions of east and west are "the directions, a right angle from the prime direction, that are closest to the rising and setting, respectively, of the sun (or moon).
Being the "default" direction on the compass, north is referred to frequently in Western popular culture. Some examples include:
In astronomy, declination is one of the two angles that locate a point on the celestial sphere in the equatorial coordinate system, the other being hour angle. The declination angle is measured north (positive) or south (negative) of the celestial equator, along the hour circle passing through the point in question.
A solar equinox is a moment in time when the Sun crosses the Earth's equator, which is to say, appears directly above the equator, rather than north or south of the equator. On the day of the equinox, the Sun appears to rise "due east" and set "due west". This occurs twice each year, around 20 March and 23 September.
A compass is a device that shows the cardinal directions used for navigation and geographic orientation. It commonly consists of a magnetized needle or other element, such as a compass card or compass rose, which can pivot to align itself with magnetic north. Other methods may be used, including gyroscopes, magnetometers, and GPS receivers.
West is one of the four cardinal directions or points of the compass. It is the opposite direction from east and is the direction in which the Sun sets on the Earth.
East is one of the four cardinal directions or points of the compass. It is the opposite direction from west and is the direction from which the Sun rises on the Earth.
A sundial is a horological device that tells the time of day when direct sunlight shines by the apparent position of the Sun in the sky. In the narrowest sense of the word, it consists of a flat plate and a gnomon, which casts a shadow onto the dial. As the Sun appears to move through the sky, the shadow aligns with different hour-lines, which are marked on the dial to indicate the time of day. The style is the time-telling edge of the gnomon, though a single point or nodus may be used. The gnomon casts a broad shadow; the shadow of the style shows the time. The gnomon may be a rod, wire, or elaborately decorated metal casting. The style must be parallel to the axis of the Earth's rotation for the sundial to be accurate throughout the year. The style's angle from horizontal is equal to the sundial's geographical latitude.
South is one of the cardinal directions or compass points. The direction is the opposite of north and is perpendicular to both west and east.
Earth's magnetic field, also known as the geomagnetic field, is the magnetic field that extends from Earth's interior out into space, where it interacts with the solar wind, a stream of charged particles emanating from the Sun. The magnetic field is generated by electric currents due to the motion of convection currents of a mixture of molten iron and nickel in Earth's outer core: these convection currents are caused by heat escaping from the core, a natural process called a geodynamo.
The four cardinal directions, or cardinal points, are the four main compass directions: north, south, east, and west, commonly denoted by their initials N, S, E, and W respectively. Relative to north, the directions east, south, and west are at 90 degree intervals in the clockwise direction.
In navigation, bearing or azimuth is the horizontal angle between the direction of an object and north or another object. The angle value can be specified in various angular units, such as degrees, mils, or grad. More specifically:
Magnetic declination is the angle between magnetic north and true north at a particular location on the Earth's surface. The angle can change over time due to polar wandering.
A compass rose, sometimes called a wind rose, rose of the winds or compass star, is a figure on a compass, map, nautical chart, or monument used to display the orientation of the cardinal directions and their intermediate points. It is also the term for the graduated markings found on the traditional magnetic compass. Today, a form of compass rose is found on, or featured in, almost all navigation systems, including nautical charts, non-directional beacons (NDB), VHF omnidirectional range (VOR) systems, global-positioning systems (GPS), and similar equipment.
In geography and geodesy, a meridian is the locus connecting points of equal longitude, which is the angle east or west of a given prime meridian. In other words, it is a line of longitude. The position of a point along the meridian is given by that longitude and its latitude, measured in angular degrees north or south of the Equator. On a Mercator projection or on a Gall-Peters projection, each meridian is perpendicular to all circles of latitude. A meridian is half of a great circle on Earth's surface. The length of a meridian on a modern ellipsoid model of Earth has been estimated as 20,003.93 km (12,429.87 mi).
Sun path, sometimes also called day arc, refers to the daily and seasonal arc-like path that the Sun appears to follow across the sky as the Earth rotates and orbits the Sun. The Sun's path affects the length of daytime experienced and amount of daylight received along a certain latitude during a given season.
The north magnetic pole, also known as the magnetic north pole, is a point on the surface of Earth's Northern Hemisphere at which the planet's magnetic field points vertically downward. There is only one location where this occurs, near the geographic north pole. The geomagnetic north pole is the northern antipodal pole of an ideal dipole model of the Earth's magnetic field, which is the most closely fitting model of Earth's actual magnetic field.
The history of geomagnetism is concerned with the history of the study of Earth's magnetic field. It encompasses the history of navigation using compasses, studies of the prehistoric magnetic field, and applications to plate tectonics.
In navigation, the heading of a vessel or aircraft is the compass direction in which the craft's bow or nose is pointed. Note that the heading may not necessarily be the direction that the vehicle actually travels, which is known as its course or track. Any difference between the heading and course is due to the motion of the underlying medium, the air or water, or other effects like skidding or slipping. The difference is known as the drift, and can be determined by the wind triangle. At least seven ways to measure the heading of a vehicle have been described.
An azimuth compass is a nautical instrument used to measure the magnetic azimuth, the angle of the arc on the horizon between the direction of the Sun or some other celestial object and the magnetic north. This can be compared to the true azimuth obtained by astronomical observation to determine the magnetic declination, the amount by which the reading of a ship's compass must be adjusted to obtain an accurate reading. Azimuth compasses were important in the period before development of the reliable chronometers needed to determine a vessel's exact position from astronomical observations.
Burt's solar compass or astronomical compass/sun compass is a surveying instrument that makes use of the Sun's direction instead of magnetism. William Austin Burt invented his solar compass in 1835. The solar compass works on the principle that the direction to the Sun at a specified time can be calculated if the position of the observer on the surface of the Earth is known, to a similar precision. The direction can be described in terms of the angle of the Sun relative to the axis of rotation of the planet.
Direction determination refers to the ways in which a cardinal direction or compass point can be determined in navigation and wayfinding. The most direct method is using a compass, but indirect methods exist, based on the Sun path, the stars, and satellite navigation.
Throughout the world, the east or sunrise point was the prime direction and signified light, life, and birth. The west and southwest were the land of the dead. Temples, cathedrals and churches were oriented to the sunrise point at the vernal equinox, to the summer solstice, or to the sunrise point on the day sacred to the saint to whom the church was dedicated. In China, however, the temple of the sun at Pekin was oriented to the sun at the time of the winter solstice.
Early Islamic maps favoured south at the top because most of the early Muslim cultures were north of Mecca, so they imagined looking up (south) towards it [...].
In the Tonga Islands, Hahagi means the northern and eastern side of an island, and Hihifo means the southern and western side. The first is derived from the preposition Hagi, 'up, upward;' the latter from the preposition Hifo, 'down, downward.' In many of the other Polynesian groups the expressions 'up' and 'down' [...] are used with reference to the prevailing trade-winds. One is said to 'go up' when travelling against the wind, and to 'go down' when sailing before it. [...] In New Zealand the north was conventionally called Raro, 'down,' and the south Runga, or 'up.'
{{cite journal}}: CS1 maint: multiple names: authors list (link)
The dictionary definition of north at Wiktionary