  Recent work has shown that the stress tensor components, such as energy
density or pressure, of a quantum field can be subject to large vacuum
fluctuations. The energy density or pressure must be averaged in time before
the fluctuations can be finite, and the probability of a large fluctuation
depends upon the details of the averaging and can be much larger than that
predicted by a Gaussian distribution. This paper explores vacuum radiation
pressure fluctuation on Rydberg atoms and their possible observable effects.
The excitation and de-excitation of a Rydberg atom provide an explicit model
for the time averaging of the radiation pressure, as the atomic polarizability
becomes time dependent, first increasing and then decreasing again by several
orders of magnitude. This switched polarizability can induce large vacuum
pressure fluctuations, which can in turn temporarily transfer linear momentum
to the atom and cause a recoil which might be observable.
