  We show how Newtonian gravity with effective (actually observed) masses,
obeying the mass-energy relation of special relativity, can explain all
observations used to test General relativity. Dynamics of a gravitationally
coupled binary system is considered in detail, and the effective masses of
constituents are determined. Interpreting our results in terms of motion in a
curved space-time background, we are led, using the Lagrangian formalism, to
consider the exponential metric as a natural space-time metric of Newtonian
gravity.
