Loose End from Stardust

Now that I've seen Stardust (a fine fantasy movie, three stars) I have a question that the film didn't answer.

The question won't be a spoiler, but spoilers might turn up in the comments, so beware if you haven't seen the movie yet.

The film opens with an astronomer writing a response to a young man's question.

What question did the young man ask the astronomers? (And who was he?)

Make Way for God's Mechanics

I see that Guy Consolmagno's new book on the religious experience of techies, God's Mechanics, is up on Amazon. Publication date is October.