10 Amazing Scientific Facts You Never Knew About Rainbows

2. The Geometry of a Rainbow

Rainbows are not just arcs but full circles. However, the ground typically obstructs the lower half, making only an arc visible. The circle is centered on the antisolar point, directly opposite the sun. The angle of light refraction within the raindrop determines the radius of the circle, typically around 42 degrees for the primary rainbow. This geometric precision is a marvel of nature, showcasing the harmony between light and water. In rare instances, such as when viewed from an airplane, the entire circular rainbow can be seen, offering a complete perspective on this natural wonder. The geometry of rainbows provides insight into the spatial dynamics of light and offers a glimpse into the mathematical beauty underlying natural phenomena.