  The Wheeler-DeWitt equation does not describe any explicit time evolution of
the wave function, and somehow related to this issue, there is no natural way
of defining an invariant inner product that provides a viable probability
interpretation. We show that both of these difficulties are solved in a
covariant canonical formulation of general relativity where the configuration
space is extended by introducing the embedding coordinates as dynamical
variables. The formalism describes the evolution of the wave function from one
spacelike slice to another, but as in the case of spatial diffeomorphisms this
is simply implemented by a coordinate change in the wave function. We
demonstrate how the time equation disappears after gauge fixing that removes
the embedding coordinates. These findings indicate that the time evolution is
trivial in a background independent formulation of quantum gravity.
