  When a charged insulating spherical shell is uniformly accelerated, an
oppositely directed electric field is produced inside. Outside the field is the
Born field of a uniformly accelerated charge, modified by a dipole. Radiation
is produced. When the acceleration is annulled by the nearly uniform gravity
field of an external shell with a 1 + beta cos theta surface distribution of
mass, the differently viewed Born field is static and joins a static field
outside the external shell; no radiation is produced. We discuss gravitational
analogues of these phenomena. When a massive spherical shell is accelerated, an
untouched test mass inside experiences a uniform gravity field and accelerates
parallelly to the surrounding shell. In the strong gravity regime we illustrate
these effects using exact conformastatic solutions of the Einstein-Maxwell
equations with charged dust. We consider a massive charged shell on which the
forces due to nearly uniform electrical and gravitational fields balance. Both
fields are reduced inside by the ratio of the g_00 inside the shell to that
away from it. The acceleration of a free test particle, relative to a static
observer, is reduced correspondingly. We give physical explanations of these
effects.
