I see no practical advatages of ether theory over ether-less theory. Ether theory does not explain more things, and have some drawbacks in addition.
If ether theory will give some practical result, say invention or whatever that is impossible without it, then we should switch to ether theory as better model.
For now, no any replicateable experiment show that there is something useful in ether theory.
Yes.
Same.
They all have mass.
You asked, I answered. If you have other questions, or want say something, you are welcome.
But please be specific and clear, so nobody have to guess what you mean.
I see no practical advatages of ether theory over ether-less theory. Ether theory does not explain more things, and have some drawbacks in addition.
If ether theory will give some practical result, say invention or whatever that is impossible without it, then we should switch to ether theory as better model.
For now, no any replicateable experiment show that there is something useful in ether theory.