Yes, it is a problem of existence because aether with the 2 specific properties that you need hasn't been shown to exist.
That's utter nonsense. I am assigning two traits, via logical deduction, to something that is known to exist. What about that are you struggling to understand? It seems very simple. The problem is not whether aether exists, it's whether it possesses those two additional properties. Disproving two properties does not disprove the whole entity. Heat didn't stop existing when people decided it wasn't made of calorics.
Dark matter in interstellar space has the property of gravitationally lensing light from far off galaxies. Since gravitational lensing has been observed, that means that dark matter exists. Wow, that was easy.
If gravity exists exactly as your model states, then dark matter would have to exist. That does not mean gravity as your model supposes exists. Do you enjoy consistently forgetting Occam's Razor?
We get two theories that explain observations. To decide between the two, we apply Occam's Razor. That is how science works. Stops forgetting that.
Do you understand what falsification means? It means that you make a testable prediction that only your theory can explain and then you test it. The ability to cross the equator is just as easily explained by RET as it is by your model.
Except that's not what you asked. You asked for something that would show my theory false, with no reference to any other theory. Besides, a possible route of Dual Earth Theory explains the Cavendish experiment: so by that logic you haven't provided what I asked for.
Nothing is uniquely explained by one theory. It's always possible to come up with some alternative. Intelligent falling for example: the hand of God pulling everything. How science works, is taking two theories that explain equal amounts (a charitable assumption for RET, sure) and applying Occam's Razor to choose between them.
In fact, RET explains it better because it doesn't require some undocumented property of aether in order to go from the northern hemisphere to the southern hemisphere or vice versa.
Undocumented how? It relies only on the notion that space is how we define distance. That's completely true. There is no special property at work. You can't ignore correction and act like that's a point.
I'm not calling you a liar. I'm just saying that you're wrong.
So, just asserting then?
Let's summarize, shall we?
Two competing theories explain all observations. Supposing that the one developed properly first takes precedence is no more than an appeal to tradition: a fallacy.
It is an established fact that, to be scientific, in choosing between two theories you apply Occam's Razor to remove the theory with the most unnecessary assumptions. Dual Earth Theory has at most two: both logically deduced. Round Earth Theory has two in its bogus definition of gravity
alone, with no logical sense to either.