We think of history as a pretty much continuous forward march of human knowledge, but it’s not as if there are a fixed number of things we are ignorant about. We know more than our medieval counterparts, sure—but can we really say that what we don’t know is any less? There’s our expanding territory of knowledge, and beyond that there is conjecture, limitless the way the space outside a picture frame is limitless. Today is Friday, and ours is a baffling universe. Won’t you comfort yourself through supernatural explanations with me?