Ion thruster
Ion thrusters are fascinating things, producing tiny amounts of thrust that are pretty much useless on Earth (with our inconvenient gravity). They’re far more useful in space however, as they’re smaller than rocket engines, and they don’t need atmospheric oxygen like a jet engine.
Ion thrusters are old technology, having been used since the 1950s, and now Jay Bowles, of the fascinating YouTube channel Plasma Channel, has demonstrated a way to make it better: multiple stages. By varying the input voltages and spacing between stages, Jay’s been able to experiment and produce a claimed exhaust velocity of 2.3 m per second.