Bead Bow imaged by Matej Grék, June '08 in Czech Republic.
s are everywhere.
Optical effects are everywhere. This 'rainbow' was produced by glass beads in the road surface. Like raindrops, sunlight is reflected once inside them to form a primary bow.
There is a difference, glass refracts light more strongly than water and consequently the bow has a radius of only about 21° - half that of a water bow.
Tthe 'bow' is bright inside, it is actually a disk.
Image ©Matej Grék, shown with permission.