Alexander Band

Alexander's band or Alexander's dark band is an optical phenomenon associated with rainbows which was named after Alexander of Aphrodisias who first described this phenomenon in Aphrodisias, Commentary on Book IV of Aristotle's Meteorology (also known as: Commentary on Book IV of Aristotle's De Meteorologica or On Aristotle's Meteorology 4), commentary 41.
The dark band occurs due to the deviation angles of the primary and secondary rainbows. Both bows exist due to an optical effect called the... plus