> You're really reaching here. For this theory to
> work, you can't just restrict exact parallel movement
> but all movement that isn't exactly perpendicular.
> And if you can only move perpendicularly, what
> effect could it possibly have?

How much a stretch is it, really? Go back to my original example. Restrict yourself to moving in two dimensions on a two-dimensional plane. From a point above you (in three dimensions), a light is shining down. You cannot move in any direction that is not perpendicular to the direction in which the waves are moving. Yet, as you draw out farther and farther from the spot directly "underneath", the light gets dimmer. Perhaps you cannot move far or fast enough to notice, but it is dimming.