UFO Propulsion

You try to put all categories of crafts in one big basket. Each civilization have it's own technology which means different way of changing state from one place to another. The biological crafts need to replace what it consumes, more advanced ones doesn't, they can exist in any state forever if they want.
The biological crafts uses a special liquid to replenish itself but is not wasteful, it can carry enough liquid to keep functional for long time.
One common fact (a misconception) is the observation of crafts as are all the same. At this time more than 2 dozens different people visit Earth in collaboration and for specific purposes.

All those things we talk about have been generated since Tesla.
We must go back to Tesla and stay there.
The big difference is the ether now days explains nothing because
it does not exist whereas Tesla explains and uses the ether with
voltage stresses.

The force is from electrostatics, no magnetic field only electric field.
So powerful is the force Tesla said his craft would go 300mps and be stable in
wind and storm as the ether to explain the kugelblitz.

We see a very bright light from air gases, like atomic lightning, surround the
craft of very high voltage.
Think of the van Der Graff generator but small.
That is what is inside.

No reflection. No mirror. No Mylar balloon. No spirit. No gods in the sky.

Think outside the light bulb.

So "hot" electrically outside it makes the air glow and the Faraday effect
keeps everyone inside stable and protected.