The four cardinal directions or cardinal points are north, south, east, and west. Most commonly used for geographic orientation on Earth, they may be calculated anywhere on a rotating astronomical body. North and south point toward the poles defined by the axis of rotation. East and west orthogonally point along and opposite the direction of rotation, respectively. Intermediate points between the four cardinal directions form the compass rose and the points of the compass. The intermediate directions are NE, NW, SW, and SE
South is always directly opposite north. On Earth, to an observer facing north and standing upright, east and west are always to the right and left, respectively. Most devices for finding orientation thus operate by finding north first. (Any other direction is equally as valid, if it can be reliably found.) Several such devices are described below.
Therefore, a more accurate fix can be made if the time of year and approximate latitude are factored in. It should also be noted that, due to the Earth's axial tilt, no matter what your location, there are only two days each year when the sun rises precisely due east. These days are the equinoxes. On all other days, depending on the time of year, the sun rises either north or south of true east (and sets north or south of true west). For all locations the sun is seen to rise north of east (and set north of west) from the March equinox to the September equinox, and rise south of east (and set south of west) from the September equinox to the March equinox.
It should also be noted that the amount that the sun appears to be either north or south depends on both the time of year and latitude of the observer. Knowing these will enable the observer to be more precise when determining the cardinal directions from the sun's position, particularly in the early morning or late afternoon.
An analogue watch clock face can be used to locate north and south. The Sun in the sky revolves over 24 hours, the hour hand of a 12-hour clock face in twelve hours. Therefore, in the Northern Hemisphere, rotate the watch such that the hour hand points towards the Sun. Then, the point halfway between the hour hand and 12 o'clock points towards the south. There are minor inaccuracies due to the difference between local time and zone time, and due to the equation of time. During daylight saving time, the same method can be employed using 11 o'clock instead of 12.
In the Southern Hemisphere, the same holds for the northern direction. The method functions poorly at lower latitudes.
The photograph shows a specialized 24-hour watch optimized for finding directions using the Sun. With the watch set to indicate local time, the hour hand points directly at the Sun. North is indicated by the local midnight position (in the Northern Hemisphere).
Picking out a specific single star may leave one uncertain they've found the right one. As an aid to identifying Polaris, the asterism "Big Dipper" may be employed. The 2 corner stars of the "pan" (those opposite from the handle) point above the top of the "pan" to Polaris. This is illustrated at this example, the beginning of a tutorial that teaches how to find Polaris. To see the rest of the tutorial click the link at the bottom of the illustration.
From the Southern Hemisphere, nightly observations of the sky directly above the vicinity of the true pole will reveal that the visible stars appear to be moving in a circular path. (It is actually the observer that is moving in the circular path.) This becomes completely obvious when a special case of long exposure photography is employed to record the observations, by locking the shutter open for most of the intensely dark part of a moonless night. The resulting photograph reveals a multitude of concentric arcs (portions of perfect circles) from which the exact center can be readily derived. The common center is exactly aligned with the true (as opposed to the magnetic) pole. (This also is true of the Northern Hemisphere, and can be used to verify one has correctly identified Polaris, which will not appear to move.) A published photograph exposed for nearly 8 hours demonstrates this effect.
The directional names are also routinely and very conveniently associated with the degrees of rotation in the unit circle, a necessary step for navigational calculations (derived from trigonometry) and/or for use with Global Positioning Satellite (GPS) Receivers. The four cardinal directions correspond to the following degrees of a compass:
An ordinal, or intercardinal, or intermediate, direction is one of the four intermediate compass directions located halfway between the cardinal directions.
These 8 words have been further compounded, resulting in a total of 32 named (and numbered) points evenly spaced around the compass. It is noteworthy that there are languages which do not use compound words to name the points, instead assigning unique words, colors, and/or associations with phenomena of the natural world.
With the cardinal points thus accurately defined, by convention cartographers draw standard maps with north (N) at the top, and east (E) at the right. In turn, maps provide a systematic means to record where places are, and cardinal directions are the foundation of a structure for telling someone how to find those places.
North (N) does not have to be at the top. Portable GPS-based navigation computers can be set to display maps either conventionally (N always up, E always right) or with the current instantaneous direction of travel, called the heading, always up (and whatever direction is +90° from that to the right).
The direction of travel required to reach the intended destination is called the bearing. Since the real world presents numerous obstacles, one must adjust his or her heading accordingly. Upon moving forward, the bearing will change so that it always points at the destination, thereby giving clues as to which way one should turn. When you are traveling, it can be easier to figure out where your next turn is, and whether to turn left or right, when the direction of travel is always up.
Children are sometimes taught the order of these directions (clockwise, from North) by using a mnemonic, such as "Naughty Elephants Squirt Water," "Never Eat Soggy Waffles", "Never Eat Shredded Wheat" ("Soggy Weet-bix" in Australia & New Zealand), "Never Enter Stinky Washroom, "Never Eat Slimy Worms," or "Never Eat Sea Weed." Also, "West and East spell WE."
In the real world there are six cardinal directions not involved with geography which are north, south, east, west, up and down. In this context, up and down relate to elevation, altitude, or possibly depth (if water is involved). The topographic map is a special case of cartography in which the elevation is indicated on the map, typically via contour lines.
During the Migration Period, the Germanic languages' names for the cardinal directions entered the Romance languages, where they replaced the Latin names borealis (or septentrionalis) with north, australis (or meridionalis) with south, occidentalis with west and orientalis with east. It is possible that some northern people used the Germanic names for the intermediate directions. Medieval Scandinavian orientation would thus have involved a 45 degree rotation of cardinal directions.
In many regions of the world, prevalent winds change direction seasonally, and consequently many cultures associate specific named winds with cardinal and ordinal directions. The classical Greeks personified these winds as Anemoi. The article on boxing the compass contains a more recent list of directional winds from the Mediterranean Sea.
Dynastic Chinese culture and some other Central Asian cultures view the center as a fifth principal direction hence the English translated term "Five Cardinal Points". Where it is different than the west, is that the term is used as a foundation for I Ching, the Five Elements and the five Naked-eye planets.
Each direction is often identified with a color, and geographical or ethnic terms may contain the name of the color instead of the name of the corresponding direction. These traditions were also carried west by the westward migration of the Turkic peoples.