  When Robert Brown first observed colloidal pollen grains in water he
inaccurately concluded that their motion arose "neither from currents in the
fluid, nor from its gradual evaporation, but belonged to the particle itself".
In this work we study the dynamics of a classical molecule consisting of three
masses and three harmonic springs in free space that does display a rotational
random walk "belonging to the particle itself". The geometric nonlinearities
arising from the non-zero rest lengths of the springs connecting the masses
break the integrability of the harmonic system and lead to chaotic dynamics in
many regimes of phase space. The non-trivial connection of the system's shape
space allows it, much like falling cats, to rotate with zero angular momentum
and manifest its chaotic dynamics as an orientational random walk. In the
transition to chaos the system displays random orientation reversals and
provides a simple realization of L\'{e}vy walks.
