Cardinal Direction - Beyond Geography

Beyond Geography

In mathematics, cardinal directions or cardinal points are the six principal directions or points along the x-, y- and z-axis of three-dimensional space.

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.

In astronomy, cardinal points of the disk of an astronomical body may be four points defined by the direction in which the celestial poles are located, as seen from the center of the disk.

A line (here it is a great circle on the celestial sphere) drawn from the center of the disk to the North celestial pole will intersect the body's limb at the North point. Similarly, a line from the center to the South celestial pole will define the South point by its intersection with the limb. The points at right angles to the North and South points are the East and West points. The North point will then be the point on the limb that is closest to the North celestial pole.