  A Lorentz invariant statistical model is presented for rotational
fluctuations in the local inertial frame that arise from new quantum degrees of
freedom of space-time. The model assumes invariant classical causal structure,
and a Planck information density in invariant proper time determined by the
world line of an observer. It describes macroscopic spacelike correlations that
appear as observable timelike correlations in phase differences of light
propagating on paths that begin and end on the same world line. The model
allows an exact prediction for the autocorrelation of any interferometer time
signal from the shape of the light paths. Specific examples computed for
configurations that approximate realistic experiments show that the model can
be rigorously tested, allowing a direct experimental probe of Planck scale
degrees of freedom.
