Western Hemisphere
From Free net encyclopedia
Image:WHemisph.jpg Western Hemisphere (capitalised) is a geopolitical term for the Americas and associated islands, derived from the geographical term western hemisphere, which is the half of the Earth that lies west of the prime meridian. However, usage has shifted so that the term generally refers collectively to the Americas, including associated islands like the Caribbean and Greenland. It is also used in a more demographic sense, for the people (and governments and nations) inhabiting these areas. The main difference between the geographical and geopolitical meanings is the exclusion of parts of Africa, Europe, Antarctica, and the eastern tip of Asia.
In other languages, the term western hemisphere (not capitalised) is only used in the literal sense, on par with the other geographical hemispheres. The word hemisphere is a geometric term that literally means 'half ball' and in geography the term is used when dividing the Earth into two halves. The most obvious dividing line is the equator, creating the northern and southern hemisphere. These hemispheres are based on the unambiguous reference points North and South Pole, which are defined by the Earth's axis of rotation and in turn define the equator. But any definition of eastern and western hemispheres requires the selection of an arbitrary meridian (plus the corresponding meridian at the other side of the Earth). Usually the prime meridian is used, which runs through Greenwich, London to define the international date line at the other side of the Earth at the 180° line of longitude.
The term eastern hemisphere is not often used in a geopolitical sense.
Image:Western Hemisphere LamAz.png
See also
fr:Hémisphère ouest fy:Westlik healrûn nl:Westelijk halfrond pl:Półkula zachodnia pt:Hemisfério Ocidental vi:Tây bán cầu zh:西半球