I was recently reminded of this book, and thought I'd share my thoughts. I actually listened to it on an MP3 player during my commute, so I don't know if it would be as delightful to read as to listen to, but I found it very engaging.
Bill Bryson covers the history of the universe, from it's creation right up to our evolution to now. He includes quite a bit on how we figured the above out, and the men and women who did the figuring.
That makes the book sound really dry, but it wasn't.
The next time you need a reminder of exactly how tiny and insignificant you are (a sensation I find oddly comforting), check it out. You are much more miniscule than you thought.