Geographical centre

In geography, a pole of inaccessibility is the farthest (or the most difficult to reach) location in a given landmass, sea, or other topographical feature, starting from a given boundary, relative to a given criterion. A geographical criterion of inaccessibility marks a location that is the most challenging to reach according to that criterion. Often it refers to the most distant point from the coastline, implying the farthest point into a landmass from the shore, or the farthest point into a body of water from the shore. In these cases, a pole of inaccessibility is the center of a maximally large circle that can be drawn within an area of interest only touching but not crossing a coastline. Where a coast is imprecisely defined, the pole will be similarly imprecise.

In demographics, the center of population (or population center) of a region is a geographical point that describes a centerpoint of the region's population. There are several ways of defining such a "center point", leading to different geographical locations; these are often confused.^[29]

The gravity model of trade in international economics is a model that, in its traditional form, predicts bilateral trade flows based on the economic sizes and distance between two units.^[31] Research shows that there is "overwhelming evidence that trade tends to fall with distance."^[32]

In astronomy, axis mundi is the Latin term for the axis of Earth between the celestial poles. In a geocentric coordinate system, this is the axis of rotation of the celestial sphere. Consequently, in ancient Greco-Roman astronomy, the axis mundi^[34] is the axis of rotation of the planetary spheres within the classical geocentric model of the cosmos.^[35]

In 20th-century comparative mythology, the term axis mundi – also called the cosmic axis, world axis, world pillar, center of the world, or world tree – has been greatly extended to refer to any mythological concept representing "the connection between Heaven and Earth" or the "higher and lower realms".^[36] Mircea Eliade introduced the concept in the 1950s.^[37] Axis mundi closely relates to the mythological concept of the omphalos (navel) of the world or cosmos.^[38][39][40] Items presented as examples of the axis mundi by comparative mythologists include plants (notably a tree but also other types of plants such as a vine or stalk), a mountain, a column of smoke or fire, or a product of human manufacture (such as a staff, a tower, a ladder, a staircase, a maypole, a cross, a steeple, a rope, a totem pole, a pillar, a spire). Its proximity to heaven may carry implications that are chiefly religious (pagoda, Temple Mount, minaret, church) or secular (obelisk, lighthouse, rocket, skyscraper). The image appears in religious and secular contexts.^[41] The axis mundi symbol may be found in cultures utilizing shamanic practices or animist belief systems, in major world religions, and in technologically advanced "urban centers". In Mircea Eliade's opinion: "Every Microcosm, every inhabited region, has a Centre; that is to say, a place that is sacred above all."^[42]

Specific examples of cosmic mountains or centers include one from Egyptian texts described as providing support for the sky,^[43] Mount Mashu from the Epic of Gilgamesh,^[44] Adam's Peak, which is a sacred mountain in Sri Lanka associated with Adam or Buddha in Islamic and Buddhist traditions respectively,^[45] Mount Qaf in other Islamic and Arabic cosmologies,^[46] the mountain Harā Bərəz in Zoroastrian cosmology,^[47] Mount Meru in Hindu, Jain, and Buddhist cosmologies,^[47] Mecca as a cosmic center in Sufi cosmology (with minority traditions placing it as Medina or Jerusalem),^[48] and, in Tenrikyo, the Jiba at the Tenrikyo Church Headquarters in Tenri, Nara, Japan. In pre-Islamic Arabia, some central temples, including the Temple of Awwam, were cosmic centers.^[49]