Apparent force that must be included if Newton's laws of motion are to be used in a rotating system. First described by Gustave-Gaspard Coriolis (1792–1843) in 1835, the force acts to the right of the direction of body motion for counterclockwise rotation and to the left for clockwise rotation. On Earth an object that moves along a north-south path, or longitudinal line, will be apparently deflected to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. The deflection is related to the motion of the object, the motion of the Earth, and latitude. The Coriolis effect is important in meteorology and oceanography as well as ballistics; it also has great significance in astrophysics.