Directional Density of Gases Under FitzGerald-Lorentz Contraction: Predictions for Rotating Optical Interferometers

In Lorentz Ether Theory, FitzGerald-Lorentz contraction affects all matter — containers, molecules, and the electromagnetic interactions between them. In a static gas, the anisotropic collision cross-sections of contracted molecules drive the density distribution toward the same anisotropy as in a solid, restoring the SR/LET equivalence. However, this equilibration proceeds at the diffusion timescale τdiff ~ L²/D — hundreds to thousands of seconds for a laboratory gas cell. In a continuously rotating experiment with period Tᵣot ~ 5–60 s, the anisotropy cannot keep pace with the changing contraction direction: the gas density remains isotropic while the solid tracks the contraction instantaneously. This timescale separation creates a measurable difference: the directional density of a gas (molecules per unit length) is isotropic, while that of a solid is anisotropic. The resulting fringe shift on rotation is ΔN = k (L/2λ) (n−1) (v/c) ², where k is the number of passes. The signal should depend on rotation speed — a direct, falsifiable prediction unique to this mechanism. We predict null results for solid-dielectric interferometers and for static (non-rotating) gas experiments.