Gauss' measurements of

space curvature from three mountaintops in Hanover in the 1820's made long before relativity theory was introduced.

the Einstein general theory of relativity with the Robertson-Walker metric, the Mach M-R relation, and the positive space curvature.

The whole space is structured similarly and all layers of space (or universes) are governed by the same physics--the Einstein general relativity with the Robertson-Walker metric, the Mach M-R relation, and the positive space curvature.

Clifford and his followers thought of

space curvature as an extrinsic property of three-dimensional space, although that word and even the concept were not to be developed for another 30 or 40 years.

Einstein's space curvature waves have never been detected on Earth although many attempts have been made.

If the cosmological constant is large we could not see out into the universe if the space curvature of the General Theory is correct.

The space curvature theory seems to preclude any way to leave the Earth or any other cosmic body without the expenditure of huge amounts of energy.

In general, relative oscillations of test-particles, both free particles and linked (interacting) particles, are derived from the space curvature (1), given by the Riemann-Christoffel four-dimensional tensor.

Thus the Synge-Weber equation provides a means for the calculation of the relative oscillations of test-particles, derived from the presence of the space curvature (gravitational fields).