Abstract

The most widely accepted explanation among scientists is that rainbow is formed by the refraction and reflection of sunlight within each individual water droplet.
According to this view, the combined effect of all the refracted and reflected rays from countless droplets creates a single rainbow visible on the horizon.
However, this explanation appears to raise a contradiction: if each droplet produces such an effect, the result should be thousands of rainbows (one per droplet), rather than a single unified arc.

The standard explanation addresses this by proposing that the geometry of the reflection is such that only those reflected rays on a specific cone—with the observer's eyes at the vertex—contribute light to the visible rainbow. This cone would define the circular shape of the rainbow.

Nevertheless, an alternative interpretation could be that the circular rainbow shape arises from the refraction of Solar disc as it interacts with ambient moisture.
This hypothesis also poses challenges, such as the fact that we do not see the entire solar disc as iridescent in the sky—only its colored edge appears.

Both explanations deserve careful and detailed analysis, which this study aims to explore.