Hi, according to several scientists, among them J.A.Peacock: A diatribe on expanding space M.J.Chodorowski: The kinematic component of the cosmological redshift E.F.Bunn&D.W.Hogg: The kinematic origin of the cosmological redshift space doesn't expand, instead the cosmological redshift is due to a combined kinematic/gravitational effect. Peacock is author of the book "Cosmological Physics". An interesting consequence is e.g. "Summing up, the expansion of the universe is never superluminal", Chodorowski. The Maxwell-Equations don't have a "stretching" term, but it seems a plausible assumption that the streching of space goes along with the stretching of a photon's wavelength, though - at least to my knowledge - there is no fundamental physical explanation for that. Or am I wrong? This leads to my question, if and how the stretching of space could in principle be proved experimentally. One can imaging long-living physicists in the center of a large void (they don't see galaxies), which supposedly expands because of its subcritical energy density, equipped with all necessary tools like watches, metersticks, ropes, light-pulse-generators, redshift analysis, whatsoever. With which kind of experiment could the physicists prove the stretching of space?