"I'd start by asking left-field questions like" I'd build two and have them push against or toward each other. Must be something funky in there. I wonder if

"I'd start by asking left-field questions like" I'd build two and have them push against or toward each other. Must be something funky in there. I wonder if the thing, or a part of the thing, changes thermal energy more/faster than it changes kinetic energy? That would be an interesting conservation solution. If it would be energetically cheaper to just heat something up that has differential IR emission on each side...