Geocentric model the coordinate system in order to predict the motions of planetary bodies, though doing so may make calculations easier to perform or interpret. A geocentric coordinate system can be more convenient when dealing only with bodies mostly influenced by the gravity of the Earth (such as artificial satellites and the Moon), or when calculating what the sky will look like when viewed from Earth (as opposed to an imaginary observer looking down on the entire solar system, where a different coordinate system might be more convenient). The Ptolemaic model of the solar system held sway into the early modern age;
Central Belt Central Belt The Central Belt of Scotland is the area of highest population density within Scotland. It has a population of about 3.5 million covering an area of approximately 10,000 km, including Greater Glasgow, Ayrshire, Falkirk, Edinburgh, Lothian and Fife. Despite the name, it is not geographically central but is nevertheless situated at the 'waist' of Scotland on a conventional map and the term 'central' is used in many local government, police and NGO designations. It was formerly known as the Midlands or Scottish Midlands, but this term has fallen out of fashion. The Central Belt lies between the Highlands