The acceleration vector in this field is NON-ZERO. But according to the geodesic-metric equation it should be
ZERO because the metric is constant with (presumably !) zero partial derivatives. The only way we can
reconcile these two conflicting values is if these derivatives were non-zero. How...
Suppose we do a constant Jacobian transformation (which is not Lorentz) of a SR (inertial)
frame, by using four linear change of variables equations. This defines an apparent field with a
constant metric (which is not the SR metric) in which there is relative acceleration of separation.