  The quantum theory of the fluctuations of the van der Waals (vdW) force
between macroscopic bodies is developed. Unlike the mean vdW force that is
determined by all quantum states that contribute to the optical absorption, the
energies of those excitations of the interacting bodies that contribute
effectively to the vdW force noise are thermal energies. Contrary to the mean
vdW force the vdW force noise drops with decreasing temperature. Due to these
differences the main mechanism of the mean vdW force and that of the vdW force
noise may be different, e.g., the mean vdW force is determined by electronic
xcitations, the force noise by the random lattice or impurity dynamics. Since
the vdW force is linear in the fields squared the dependence of the vdW force
noise correlation function on time difference is determined not by one but by
two frequencies: the spectral density depends not only on the frequency of its
measurement but also on the integral over the second frequency. The dependence
of its integrand on this frequency and emperature is quantum-like even at small
measurement frequency, and such may be the behavior of the vdW noise. In the
case of interacting metals the vdW force noise is enhanced by dc voltage
applied across these metals. This additional noise is proportional to the
voltage squared and to the spectral density of the random electric field at the
frequency of noise measurement. The theory is in qualitative agreement with
experiments.
