Twice last night I watched the first half of an interesting show on the History channel. The first time, I turned away because something else was on, and the second time I fell asleep at about the same point where I had turned away.
The show is called "Afraid of the Dark." It went into detail about life used to be like after dark and why we are wired to be afraid of the dark. We historical fiction writers often forget or don't understand how dark night used to be, and how long night was because of how dark it was. It's an older show, from 2009 or earlier, so you might have seen it before.
If you write historical fiction, you might want to watch for this to come on again. I don't see it listed as coming on again soon on the channel's Web site, but it is available on DVD at http://shop.history.com/detail.php?p=110042&v=history&ecid=PRF-2103387&pa=PRF-2103387.
I wish I had written down the title of a book by an author who was one of the commentators. It might be an interesting addition to my reference shelf.