My friend and Hive Overmind co-blogger Sean Carroll is a theoretical cosmologist, which means he thinks about why the Universe is the way it is, and applies what we know about physics and mathematics to try to understand it. His particular interest is the flow of time, and why it goes from the past to the future. That may seem like a weird thing, but in fact we don't understand why we remember the past and not the future. Space goes in all directions, but time is a one-way street. Why? This question is so interesting, in fact, that it caught the attention of noted scientist and thinker Stephen Colbert, who discussed it (and Sean's new book, From Eternity to Here) on his TV show last week. I highly recommend taking a look at the clip Sean has on his blog; he's a great example of not only someone trying to pry open the secrets of everything, but also of someone who enjoys doing it, and does a great job explaining it under what must be the high-pressure gaze of Colbert. My congrats to Sean for joining the long list of my friends who have been on that TV show, and of course I'm not jealous at all. Really. Not even a little tiny bit. Seriously.