  We study the quantum electrodynamics (QED) vacuum in the presence of a body
rotating along its axis of symmetry and show that the object spontaneously
emits energy if it is lossy. The radiated power is expressed as a general trace
formula solely in terms of the scattering matrix, making an explicit connection
to the conjecture of Zel'dovich [JETP Lett. 14, 180 (1971)] on rotating
objects. We further show that a rotating body drags along nearby objects while
making them spin parallel to its own rotation axis.
