  From calculations of the variance of fluctuations and of the mean of the
energy density of a massless scalar field in the Minkowski vacuum as a function
of an intrinsic scale defined by the world function between two nearby points
(as used in point separation regularization) we show that, contrary to prior
claims, the ratio of variance to mean-squared being of the order unity does not
imply a failure of semiclassical gravity. It is more a consequence of the
quantum nature of the state of matter field than any inadequacy of the theory
of spacetime with quantum matter as source.
