Paul Sutter is an astrophysicist at The Ohio State University and the chief scientist at COSI Science Center. Sutter is also host of the podcasts Ask a Spaceman and RealSpace, and the YouTube series Space In Your Face.  We all know that the universe is expanding, right? Well, if you weren't aware, now you are. We live in an expanding universe: Every galaxy is flying away from every other galaxy. This naturally leads to a common question: If the universe is expanding, what's it expanding into? More universe? Nothing? Something resembling a vague fog? Where's the edge of our cosmic soap bubble? Well, our universe does have an edge - that is, if by "our universe," you mean the observable universe.