  It is well known that optical media create artificial geometry for light, and
curved geometry acts as an effective optical medium. This correspondence
originates from the form invariance of Maxwells equations, which recently has
spawned a booming field called transformation optics. Here we investigate
responses of three transformation media under electromagnetic pulses, and find
that pulse radiation can induce unbalanced net force on transformation media,
which will cause translation and rotation of transformation media although
their final momentum can still be zero. Therefore, the transformation media do
not necessarily stay the same after an electromagnetic wave passes through.
