Abstract
Rotation, contrary to translational motion, is defined absolutely. As a consequence of this general principle, a resistive torque is felt by a rotating piece of dielectric by the scattering of the fluctuations of the QED (quantum electrodynamics) vacuum. A rotating dielectric radiates torque, and part of this torque could be absorbed by a nonrotating dielectric nearby. This torque on a nonrotating object could be more easily measured than a contribution to the damping of the rotation of a spinning piece of matter.