Regions of the world

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The regions of the world or regions of the heavens (Latin: plagae mundi ) are the dividing points of the horizon divided into 4, 8, 16 or 32 equal parts, as expediently also used by modern compasses . Today they are outdated terms from spherical astronomy and were previously used mainly in nautical science . Since seafarers indicated the direction of the winds in this way, these areas were sometimes also called the 32 winds. Today, the term “region of the world” is only used in a figurative sense as an approximate term for larger geographical parts of the earth's surface.

Determination of the world regions

The division into regions of the world is based on the midday line of the respective location . The noon line of a place is the astronomical meridian, the north-south line. The points at which it meets the horizon were called the midnight and noon point (now called north and south ). The perpendicular to the local noon line cuts the horizon at the evening point and the morning point , today called West and East.

The four points north, east, south and west were called the cardinal points , today mostly referred to as the four cardinal points. They divide the horizon into four equal quadrants, the main areas (lat. Plagae cardinales ): midnight , morning , noon and evening .

The first four secondary regions (Latin: plagae intermediae ) correspond to the four secondary directions of today and also have the same names: northeast , southeast , southwest and northwest .

By a further halving obtained the eight second sub areas, analogous to the second side of the compass: north-northwest , west-northwest , west-southwest , south-southwest , south-southeast , east-southeast , the east-northeast and north-northeast .

A further halving of the now sixteen main and sub-areas results in the third sub-areas. They are either in a main area or in a first secondary area. This determines the first part of the name which is connected by the syllables "gen" with that of the main area according to which the area to be named differs from the adjacent area. These names are therefore: north-west, north-west-north, north-west-west, west-north-west-south-south, south-west-west, south-west-south, south-gen- West, south-east, south-east-south, south-east-east, east-south, east-north, north-east-east, north-east-north and north-east.

Origin of the term

The system of the world regions probably goes back to the Romans . They coined the term plagae mundi and initially divided the world they knew into four parts, which they determined according to the Roman sundial :

  • They called the areas over which, from their point of view, the sun never stood (there below the northern horizon) plaga septentrionis , the area of ​​the seven oxen, after the seven bright stars of the Big Dipper .
  • According to the Roman sundial, which counted away from sunrise , the plaga orientalis , the Orient (rising sun), was at 1, 2, 3 and 4 o'clock ,
  • at 5, 6, 7 and 8 o'clock the midday area, plaga meridiana
  • and at 9, 10, 11 and 12 o'clock as the fourth area the Occident , plaga occidentalis .

For the Roman census of the world regions you have to know that the highest point of the sun was exactly 6 o'clock, but the individual 12 hours were different according to the Roman sundial. A subdivision of the four regions of the world into eight additional regions was based on the Venti , the Roman winds:

literature

  • JST Gehler: Physical Dictionary . 1798.
  • Hermanni Contractus : Patrologia Latina . In: De utilitatibus astrolabii libri duo . No. 143 . ed.Migne, Paris 1882, p. 389-412 .