  We show that results of a simple dynamical gedanken experiment interpreted
according to standard Newton's gravitational theory, may reveal that
three-dimensional space is curved. The experiment may be used to reconstruct
the curved geometry of space, i.e. its non-Euclidean metric. The perihelion of
Mercury advance and the light bending calculated from the Poisson equation and
the equation of motion in the curved geometry have the correct (observed)
values. Independently, we also show that Newtonian gravity theory may be
enhanced to incorporate the curvature of three dimensional space by adding an
extra equation which links the Ricci scalar with the density of matter. Like in
Einstein's general relativity, matter is the source of curvature. In the
spherically symmetric (vacuum) case, the metric of space 3gik that follows from
this extra equation agrees, to the expected accuracy, with the metric measured
by the Newtonian gedanken experiment mentioned above.
