Sebastian Thrun isn't watching the road when his driverless Volkswagen SUV veers off-course and heads for a 50-foot precipice. He's in the backseat looking at a laptop that's tracking the car's brain, which consists of seven Pentium processors. When he feels the car swerve abruptly to the left, Thrun looks up, pushes aside a bundle of cables blocking his view, and realizes that his car is about to pull a Thelma and Louise.

Many of PopSci's Brilliant 10-scientists who are pushing the limits of their disciplines-labor in abstract realms, generating calculations, analyses and other intangibles. But a couple of them work very much in the here and now, even risking their own safety when necessary.

Maydianne Andrade, 35, a biologist at the University of Toronto, studies the mating habits of Australian redback spiders, and keeps hundreds of these poisonous critters in her lab. She and her colleagues made the following video, which shows a pair of redbacks in flagrante.