I don't know if I thought this because it was something my mom told me when I was little or if I just sort of made it up on my own. I always thought that if you ran the microwave without anything in it terrible things would happen. Maybe the microwave would blow up or lightning would strike from above. Something like that.
Well, I ran the microwave for a while two minutes on high without anything in it, and nothing happened. I thought the green beans were already in there, but it turns out I was mistaken (perhaps distracted by the zoo of animal figurines gathering on my counter as my daughter rounded them up. So I was wrong. And yes, the microwave worked just fine immediately after and a few minutes later when I warmed up Charlotte's leftover pizza.
Whew! I'm not going to repeat the experiment, but I feel better about not causing the end of the world.