Are you interested in learning more about finding your position with a sextant and my slide rules? Are you curious how to calculate the current time based on the position of the moon? Do you want to hear me say "uhm" a lot? Then you might enjoy this poorly produced followup to my #39c3 talk explaining some of the more complicated bits of celestial navigation: https://www.youtube.com/watch?v=LcTrZdWb5fc