Well, i knew it
Laugh all you want, but the quartz in the chambers, the positioning and the electrical conductivity of the pyramids suggested all along they could vibrate to supersonic speeds, almost as if they were designed to rub against a metal plate of some sorts. I think you all are underestimating the importance of keeping one's lawn well trimmed when you are an alien millions of light years away from the closest intergalactic convenience store.