This is a question about what we can observe about space. This is not a relativistic question, or about the expansion of space or about “aether”. Some of the aspects of space as I understand it are: Space has volume. Space has the non-zero properties of permeability and permittivity. Space has a single occupancy rule i.e. two objects with the same spin cannot occupy the same space at the same time. As far as we know, the properties of Space are constant and uniform throughout the universe. It also seems that objects and Space are not fixed to each other in that objects (as we say in the vernacular) travel though Space such as galaxies, stars, planets and light. To keep the idea that there is not a special aspect to an observer we could also say that “space moves though us”, just as well as “we move though space”. So the question is; can we determine if space moves? It seems to me that with the properties of Space being constant and uniform that there should be no change in an object by Space as the object moves though Space. The converse is that if Space were moving there would not be any change in an object. It therefore seems to me that we cannot determine if Space is moving or if Space is fixed. I welcome any thoughts or insights others may have about this.