You’ve always believed that rainbows are half-circles, correct? You’ve also probably always longed to find a pot o’ gold at the end at that half-circle, right?
Prepare to have your mind blown (and your pot o’ gold dreams ruined). A crane operator in St. Petersburg, Russia filmed a rainbow from a 1,500-foot skyscraper that proves that the shiny, majestic bands in the sky are in fact full circles, not arches.
Apparently there’s a simple explanation behind the full-circle rainbow phenomenon. Due to the earth’s curvature, only the upper half of rainbows can be seen from the ground with the human eye. If you ascend to a high point, say on an airplane or the top of a tall building, you can see that rainbows are full circles.
According to The Physics Classroom, “The circle (or half-circle) results because there are a collection of suspended droplets in the atmosphere that are capable concentrating the dispersed light at angles of deviation of 40-42 degrees relative to the original path of light from the sun.
The explanation continues, “These droplets actually form a circular arc, with each droplet within the arc dispersing light and reflecting it back towards the observer.”
Take a look at the original video below.