How Rainbows Form: Science Behind the Colorful Arc #2320852 (License: Personal Use)

This educational diagram illustrates the optical process behind rainbow formation: white sunlight enters a spherical raindrop, refracts upon entry, reflects off the inner surface, and refracts again upon exiting, separating into the visible spectrum. The arc shape arises from the specific 42-degree angle at which light reaches the observer’s eye for red and 40 degrees for violet. Multiple raindrops at varying angles collectively produce the full circular band of colors.

Used on science education pages, weather or optics articles, school curriculum resources, and科普 (popular science) websites; targets users seeking clear, visual explanations of natural phenomena, especially students, teachers, and curious learners.