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 bank In this context, independence is usually defined as the central bank's operational and management independence from the government. Central bank independence is usually guaranteed by legislation and the institutional framework governing the bank's relationship with elected officials, particularly the minister of finance. Central bank legislation will enshrine specific procedures for selecting and appointing the head of the central bank. Often the minister of finance will appoint the governor in consultation with the central bank's board and its incumbent governor. In addition, the legislation will specify banks governor's term of appointment. The most independent central banks enjoy a fixed non-renewable term