A lot of innovation depends on the masses to really get going. Take the problem of healthcare and education around the world: we just don't have enough experts to go around. That's where mental health expert Vikram Patel and UNICEF’s Jordan Naidoo see lay people stepping up to the plate. Then, social scientist Toby Miller explains that even if we all cut down on using paper, it isn't enough to help the planet — our digital footprint also needs to be accounted for. Columbia's Ruth DeFries tells us why our desperate quest for food created civilization, as well as huge problems we need to fix. Plus, an object from the past that ended up on everyone's doorstep in America.