There is a connection between vacuum energy density and the Casimir effect , see :
Another reference can be found here:
The Casimir vacuum between parallel plates has a lower energy density than the vacuum outside the plates. That's what puts the plates in (attractive ) motion in the original Casimir experiment.
Based on these references (and many others) in vacuum, in the absence of any other forces or fields, it seems that matter tends to follow the gradient of the vacuum energy density ( for example from high vacuum energy density to low vacuum energy density )?
Question. In vacuum, in the absence of any other forces, a ship with a large number of Casimir plates at one end , will it tend to move without the need of any fuel (as slow as it may)? This asymmetric "pressure" phenomenon would be caused by the gradient of vacuum energy density.
A picture's worth a thousand words. The design can be seen here:
In this design the Casimir plates are parallel to the direction of travel. The ship moves for the same reason the plates are pushed together in the original Casimir experiment, following the gradient of the vacuum energy density.
If you want to see some feedback from physics:
If this design is not feasible , please explain. If it is feasible, is anyone interested in testing it (this is not garage work)?