When the sun slides out of sight—or, more accurately, when Earth rotates so that your particular place on the planet is no longer exposed to our day star—but before darkness consumes the landscape, there is the magical, muted time of twilight. The word comes to us from the Old English twyelyghte, or half-light, when the vivid colors of the day fade to a shadow palette of grays. Of course, the colors don’t change, but our ability to discern them does. Most animal eyes have a mix of rods and cones,…
