A metric theory of gravity
IF most all of the 1/c2 order, post-Newtonian terms in the N-body equations of motion – motional, gravitomagnetic, non-linear, inductive, et all....contribute to the measured details of the lunar orbit, so LLR achieves near-completeness as a gravity experiment and probe
Possible confusion due to Sun’s quadripolar tidal field, which produces cos2D term (but 90º out of phase).
MTG defines a metric tensor field throughout all space
The metric tensor field quantifies intervals, frame independent measures of the separation between two events.
In an inertial frame (flat space), the squared-interval is the squared-distance between two events, minus the squared-distance light travels in the time between the events
The metric tensor field describes the “shape” (curvature) of space
All physics, gravitational and otherwise, occurs in the physical spacetime described by the metric tensor field.
The only dynamic field is the metric tensor field
(loosely (but a nice girl )analogous to the EM field in electromagnetics)