Whatever they use, "Reactionless" and "Soundless" appear to be common characteristics along with no apparent Inertia.
All Human-based technology that I know of depends upon action / reaction and generates sound, usually a lot.
Even if we figure out quiet, reactionless drives and how to ignore Inertia, we'd still produce air noise / turbulence and sonic booms.
So for now, we're stuck with Fiction.
The Wile E. Coyote Giant Slingshot Drive sounds promising.
Otherwise, a Turbo Encabulator might have to suffice with its Modial Interaction of Magneto-Reluctance and Capacitive Directance. (Instead of the conventional relative motion of Conductors and Fluxes)
Failing that, the Atomic Bomb Drive is effective but requires a whole lot of surplus bombs.
If we ever figure out how to tap into it, the power of Stupidity could probably propel a planet across the Universe in a millisecond.
Sometimes Great Ideas come out of being Silly.
But probably at best maybe a Chuckle.
Keri
