Western Hemisphere
From Freepedia
Western Hemisphere (capitalised) is a geopolitical term for the Americas and nearby islands. It is derived from the geographical western hemisphere, which is the half of the Earth that lies west of the prime meridian, but usage has shifted so that the term refers only to North, Central and South America, and the islands of the Caribbean. It is also used in a more demographic sense, for the people (and governments and nations) inhabiting the continent. The main difference between the geographical and geopolitical meanings is the exclusion of parts of Africa, Europe and Antarctica (and the eastern tip of Asia) in the latter.
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. One might argue that this is a eurocentric choice, which would make the more common geopolitical meaning of 'the Americas' eurocentric as well.
The term eastern hemisphere is not commonly used in a geopolitical sense.
