Davis' inventions inhabit a space between science and art, their utility a question mark. For years, he worked on an "audiomicroscope," which allows viewers to listen in on tiny creatures like nematodes, bacteria, or the rotifers at right. (Davis explains that the device bounces red laser light off the organisms and translates the results into sound.) He also built a tool that lets him "fish" for single-celled organisms like the paramecium. The device is a 25-micron hook connected to a fishing line and an amplifier that scales up the organism's struggle, so that reeling in a cell can feel like netting a large tuna.

These devices may or may not find practical applications. Either way, they animate some researchers. "We spend so much time as scientists trying to convince people that exploring the world is exciting, that reality is itself beyond breathtaking," says Charlie Marcus, a physics professor at Harvard and longtime friend of Davis'. "Joe understands that intuitively."