Fran,
I think this is part of the difference between cavities that exhibit "negative"
internal pressure or "positive" internal pressure. If we start by assuming that
Lorentz Invariance applies to nanocavities then, at first, we expect the same
pressure inside the cavity as outside the cavity, except for one little detail:
Casimir Plates actually move! How can this be? Clearly, if we are correct, the
pressure actually is the same in each time frame, but faster time means more
instances of impulse as counted from a slower time frame; this gives us a
positive pressure cavity. If time passes slower inside the cavity, then we have
a "negative pressure" cavity. In other words, the time change is what is
actually causing the Casimir Effect.
Therefore, a cavity with a U-shaped cross section of the right materials, size
and proportions can probably be designed so as to experience equal forces on
its ceiling as on its roof, but at different rates of time. Therefore, a
properly designed cavity will experience a net force.
What do you think?Scott,
