Geocentric model Geocentric model In astronomy, the geocentric model (also known as geocentrism, or the Ptolemaic system) is a superseded description of the Universe with Earth at the center. Under the geocentric model, the Sun, Moon, stars, and planets all orbited Earth. The geocentric model served as the predominant description of the cosmos in many ancient civilizations, such as those of Aristotle and Ptolemy. Two observations supported the idea that Earth was the center of the Universe. First, from anywhere on Earth, the Sun appears to revolve around Earth once per day. While the Moon and the planets have their own motions,
Overkill (term) Overkill (term) Overkill is the use of excessive force or action that goes further than what is necessary to achieve its goal. It implies that, while the goal was accomplished, there was collateral damage as a result. It may be a literal term referring to physical damage, though it is also used in colloquial conversation as a metaphor. An example is killing an ant with a sledgehammer. "Overkill" is especially used to refer to a destructive nuclear capacity exceeding the amount needed to destroy an enemy. The term is attested from 1946 and was in common use during the Cold