Q and BA is the videoblog from Bad Astronomy (www.badastronomy.com), where every week astronomer Phil Plait answers reader questions. Got a cosmic question you want answered? The sky's the limit!
This is the audio-only version of Episode 6: I Am Your Density. Foor show notes, go to the Bad Astronomy Blog: http://www.badastronomy.com/bablog/2007/03/11/q-and-ba-episode-6-i-am-your-density/