Rotation
Videos
Rotation, also known as rotational motion or rotary motion, is the movement of an object that leaves at least one point unchanged. In 2 dimensions, a plane figure can rotate in either a clockwise or c
Star trails caused by the Earth's rotation during the camera's long exposure time
Euler's rotation theorem
Videos
In geometry, Euler's rotation theorem states that, in three-dimensional space, any displacement of a rigid body such that a point on the body remains fixed, is equivalent to a single rotation about so
Figure 1: Blue great circle on sphere transforms into red great circle when rotated about diameter through O.
Figure 2: Arcs connecting preimage α and image a of A with bisector AO of the angle at A.
Figure 3: O goes to O′, but O′ must coincide with O.