Let's say you go back in time and kill your grandfather. This means you were never born. And more importantly, it means that you're not here, about to listen to Gobbledygeek either, something I believe we can all agree would be a grave tragedy. Paul and AJ discuss just such a time travel paradox, as well as methods of time travel and its reflections in pop culture, in this week's episode. We've got the flux capacitor fired up; hop in. Plus: news, AJ's review of Hereafter, and Formspring questions!