I cannot edit previous message, so let discuss a bit further. I'm sick, has high body temperature and unable sleep anyway.
To develop intuition, first you must understand that we are not moving through space, we are propagating through space, because we are waves. Actually, nothing is moved, hence no drag between material objects and space.
I will use video above as example. If you measure speed of sound in water between waves around droplets, you will found that speed of sound is constant, regardless of speed of droplet, because water is not moving at all. Water is contracting and expanding in place. We can perceive «lower» speed of sound in water in case of really big waves, because distance to travel will increase slightly. This is how gravitational waves are caught. Otherwise we are out of luck: we are counting waves to measure distance and time, and that count is not changing when space contracts and expands.
So the only two solutions I see to prove that space is real thing, like water, using waves only, is to:
1) cool vacuum below 0K — cooled vacuum will have slightly different speed of light (someone in USA is already working on that, shortly after discussion about „frozen vacuum“ at HN ;-). It's possible to cool or heat water using acoustic, but we are propagating through space, so cooled vacuum will be left in place while we will propagate away. Hard task. Can be done in interstellar space if ship will be able to stand at same place, or if large enough setup will be used quickly.
2) measure tiny asymmetry of front vs back of pilot wave using Sagnac effect to show that there are small deviations between predicted values and actual values, which are varying over year, as direction of movement and our position in Solar system changes (Solar system already had that asymmetry as measured by Voyagers). I saw (or I think that I saw) paper with exactly that information: experiment with large Sagnac interferometer conducted for over year with high precision which was focused on these deviations, but I still cannot find it. :-(
To develop intuition, first you must understand that we are not moving through space, we are propagating through space, because we are waves. Actually, nothing is moved, hence no drag between material objects and space.
I will use video above as example. If you measure speed of sound in water between waves around droplets, you will found that speed of sound is constant, regardless of speed of droplet, because water is not moving at all. Water is contracting and expanding in place. We can perceive «lower» speed of sound in water in case of really big waves, because distance to travel will increase slightly. This is how gravitational waves are caught. Otherwise we are out of luck: we are counting waves to measure distance and time, and that count is not changing when space contracts and expands.
So the only two solutions I see to prove that space is real thing, like water, using waves only, is to:
1) cool vacuum below 0K — cooled vacuum will have slightly different speed of light (someone in USA is already working on that, shortly after discussion about „frozen vacuum“ at HN ;-). It's possible to cool or heat water using acoustic, but we are propagating through space, so cooled vacuum will be left in place while we will propagate away. Hard task. Can be done in interstellar space if ship will be able to stand at same place, or if large enough setup will be used quickly.
2) measure tiny asymmetry of front vs back of pilot wave using Sagnac effect to show that there are small deviations between predicted values and actual values, which are varying over year, as direction of movement and our position in Solar system changes (Solar system already had that asymmetry as measured by Voyagers). I saw (or I think that I saw) paper with exactly that information: experiment with large Sagnac interferometer conducted for over year with high precision which was focused on these deviations, but I still cannot find it. :-(