Whenever you bring together Neil deGrasse Tyson and Richard Dawkins -- one the public face of astrophysics, the other the public face of biology -- you're pretty much guaranteed a good crowd and a spirited conversation. And that's what students got in September 2010, when the scientists shared the stage at Howard University and considered some big enchilada questions. For example: Why did our mind -- from an evolutionary point of view -- lead us to abstract mathematics, which drives the major discoveries in physics? What are the chances that we'll discover intelligent life in the universe, and, if they discover us (rather than the other way around), could we, as a civilization, be in big trouble? Is natural selection operative throughout the universe and would aliens look anything like us? And why is The Blob a much better alien than ET? In short, they're considering just the kinds of mind-bending questions that college students love to entertain -- and hopefully you do to. Their conversation runs about 50 minutes and a Q&A follows.