Question

Is it possible that total internal reflection plays a role in rainbows? Explain in terms of indices of refraction and angles, perhaps referring to Figure 25.48. Some of us have seen the formation of a double rainbow. Is it physically possible to observe a triple rainbow?

Short answer

A rainbow is a completely reflected light beam in the sky.

The third rainbow arc is difficult to spot.

Step-by-step solution

Definition of reflection

The change in the direction of a wavefront at an interface between two different media causes the wavefront to return to the medium from which it originated is referred to as reflection. Reflection of light, sound, and water waves are common examples.

Explanation

Total internal reflection refers to the complete reflection of a ray of light from the surrounding surfaces back into a medium such as water or glass. It occurs when the angle of incidence exceeds the critical angle.

When we see a rainbow, a beam of light is completely reflected back to us.

The third arc of a triple rainbow is behind a watcher, in the part of the sky where the sun can be seen, so even if it occurs, it would be extremely difficult to notice.