Physics

What causes ionic wind?

The phenomenon of ionic wind has been known about for centuries: by applying a voltage to a pair of electrodes, electrons are stripped off nearby air molecules, and the ionized air collides with neutral air molecules as it moves from one electrode to the other. The effect is easy enough to produce that it often appears at science fairs, and may even have a future in spacecraft propulsion. However, exactly what causes ionic wind is still an open question.