For thousands of years people have been looking into the sky and seeing things they simply did not understand. They labeled them as best they could, calling them flaming swords, fiery chariots, twirling shields, and, eventually, flying saucers. They offered descriptions of these bizarre objects that seem, even today, to defy explanation. These early accounts suggest something that is beyond the commonplace and the mundane, something that is extraordinary, a phenomenon that began appearing before there was a written language to record observations of it.
In today's world, there have been hundreds of thousands, if not...