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;
Unconverted long-term prisoners in North Korea, and Revised Romanisation for places now in South Korea. Unconverted long-term prisoners Unconverted long-term prisoners is the North Korean term for northern loyalists imprisoned in South Korea who never renounced "Juche". The North Korean government considers them to be "pro-reunification patriotic fighters", while South Korean scholars have described them as "pro-communist spies". In March 1998, South Korean president Kim Dae-jung declared an amnesty for long-term prisoners over the age of 70, as well as some suffering from disease. In February 1999, President Kim declared another amnesty for 17 unconverted long-term prisoners. In 2000, as part of the