Bow In Asphalt Paint
July 22, 2003
I was on vacation in the Smokey Mountains of eastern Tennessee, getting ready to take a trail to one of the higher summits, when my brother pointed at a rainbow that was shining on paint marking the edge of the road. It came to me that the small glass beads that make the paint reflective were creating the bow. Unlike a water drop bow, having a radius is 42 degrees, the bow from glass beads in the road-paint has a radius of but 28 degrees, resulting from the higher refractive index of glass.