I have an idea generation question related to worldbuilding.stackexchange.com/q/249517/75: I have a universal ether that exists throughout reality, and only certain forms of matter can interact with it, such as etheric keels, which move through it easily in one direction but not in others, like a bundle of pipes in water. I was wondering, what could I make that will take energy/power and provide a thrust against the ether like a jet or a rocket, that isn't a screw made from keels?

Okay so I have got the theme of my story to be:
Believing The Unbelievable