It turns out the recognizable half-circle arch of a rainbow is a complete lie. When you’re standing on the ground looking up at a rainbow in the sky, the curvature of the Earth usually blocks its bottom half. But when viewed from a higher vantage point, like from a plane, or the top of a crane, rainbows are magically revealed to be a complete circle.
The science of rainbows: it’s something we’re all taught in grade school. Airborne water droplets act like little prisms, bending and splitting light. Mix enough water and sunshine, and you get a brilliant bow of color.