  An interpretation of general relativity is developed in which the energy used
to lift a body in a static gravitational field increases its rest mass.
Observers at different gravitational potentials would experience different mass
reference frames. It is shown that bodies falling in a Schwarzschild field
exhibit the relativistic mass/energy relationship from special relativity. This
new result is independent of the choice of coordinates. The proposed approach
provides a physical explanation for gravitational energy, which is localized as
a scalar function intrinsic to general relativity. Applying this model to the
Robertson-Walker metric demonstrates that time-varying fields induce a net
energy transfer between bodies that is not exhibited in static fields.
