Khawaja

Rotation

Rotation is the circular movement of an object around an axis of rotation. A three-dimensional object may have an infinite number of rotation axes. If the rotation axis passes internally through the body's own center of mass, then the body is said to be autorotating or spinning, and the surface intersection of the axis can be called a pole. A rotation around a completely external axis, e.g. the planet Earth around the Sun, is called revolving or orbiting, typically when it is produced by gravity, and the ends of the rotation axis can be called the orbital poles. more »