Editing Rotation (section)

{{Short description|Movement of an object around an axis}}
{{About|movement of a physical body}}
{{Redirect|Rotate|the song|Rotate (song)|the ghost town|Rotate, Kansas}}
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[[File:Rotating Sphere.gif|right|thumb|A sphere rotating (spinning) about an axis]]

'''Rotation''' or '''rotational/rotary motion''' is the circular movement of an object around a central line, known as an '''''axis of rotation'''''. A [[plane figure]] can rotate in either a [[clockwise]] or counterclockwise sense around a perpendicular axis intersecting anywhere inside or outside the figure at a ''[[center of rotation]]''. A [[solid figure]] has an infinite number of possible axes and [[angles of rotation]], including [[chaotic rotation]] (between arbitrary [[orientation (geometry)|orientations]]), in contrast to [[rotation around a fixed axis|rotation around a {{em|fixed}} axis]].

The special case of a rotation with an internal axis passing through the body's own [[center of mass]] is known as a '''spin''' (or ''autorotation'').<ref name="Wormeli2009"/> In that case, the surface intersection of the internal ''spin axis'' can be called a ''pole''; for example, [[Earth's rotation]] defines the [[geographical pole]]s. 
A rotation around an axis completely external to the moving body is called a '''revolution''' (or ''[[orbit]]''), e.g. [[Earth's orbit]] around the [[Sun]]. The ends of the external ''axis of revolution'' can be called the ''[[orbital pole]]s''.<ref name="Wormeli2009">{{cite book | last=Wormeli | first=R. | title=Metaphors & Analogies: Power Tools for Teaching Any Subject | publisher=Stenhouse Publishers | year=2009 | isbn=978-1-57110-758-9 | url=https://books.google.com/books?id=BvSOdG0UwysC&pg=PA28 | access-date=2023-07-27 | page=28}}</ref>

Either type of rotation is involved in a corresponding type of [[angular velocity]] (spin angular velocity and orbital angular velocity) and [[angular momentum]] (spin angular momentum and orbital angular momentum).