 Now asymmetrical capacitors have been around for 100 years. People have seen thrust in them, but they've been kind of ignored from the scientific community because of an ion wind effect if you do it in air. But if you ignore that, and if you actually test it in vacuum and test it correctly, you'll see that you'll get the thrust actually in the opposite direction of the ion wind. But that's a geometry effect. So parallel plate capacitors are parallel. If you change the dimension of one of them, you'll get a thrust.