  It is argued that, in order for the gravitational field to be propagated as a
wave, it is necessary for it to satisfy a further set of field equations, in
addition to those of Einstein and Hilbert, and these equations mean there is a
preferred coordinate frame, called the Global Inertial Frame, giving rise to a
unique metric . The implication is that a true gravitational field is not
compatible with Einstein's Principle of Equivalence, which is in contradiction
with his other fundamental concept of locality. The additional field equations
ensure that gravitational collapse does not go below the Schwarzschild radius,
thereby excluding the possibility of singular solutions (black holes) of the
Einstein-Hilbert equations. Such solutions would also violate Einstein's
locality principle.
