It's weird to think number twos are particularly heroic. But it's true--poop can save the world Explore poop's murky past, what happens to poop after you flush it away, and how we can use the brown stuff to power our cars, homes, and even rockets Discover glow in the dark pee, whether you can get paid to use the toilet, and cutting-edge scientific research into how we can use biofuels to power our planet and save us from climate...