There was a lanky man on the couch at the kids’ birthday party. I noticed him for some reason. No special reason. He sprang up and addressed us: were we involved in the sciences at all? He had an idea for an invention, helium-filled balloons that were only half-filled, so they’d hover in the air, immobile. They didn’t even have to be balloons—they could be objects. Ornaments. He wondered why that didn’t exist yet. I agreed. I was supportive. From time to time he spat out a fragment of the corn chips or Cheetos or whatever it was he’d been eating from the snack table. He’d wipe his mouth momentarily, but not self-consciously, and continue. And what about ketchup packets? Why were they so messy? So inefficient? You tear it open, ketchup gets on your fingers. You squeeze it, squeeze it till you’re sick and tired and still there’s a little bit left. A tiny pocket of wasted ketchup. Multiplied by billions. Consider the wasted food. He had a point. Finally there was a lull and I wished him luck and slipped away.