Re: Why does electrostatic attraction in water decrease?

["John S. Denker" <jsd@MONMOUTH.COM>]

Bob Sciamanda wrote:
> ... Panofsky says that the effects of the dielectric field (modelled
> by the fields of equal and opposite bound surface charges) on each
> capacitor plate cancel.

That's true in the narrow context of a parallel-plate
capacitor (i.e. uniform field).  But here we're talking
about non-uniform fields, in which case the effect of
the induced charges certainly doesn't cancel.

To see this, consider the force on a dielectric in
the inhomogeneous near a point charge.  I would think
the dielectric causes an equal-and-opposite reaction
(force) on the point charge, wouldn't you?  Conservation
of momentum and all that.