Dispersion of Light

Rainbow formation is a meteorological phenomenon that occurs due to the dispersion of light. When light passes through a medium, such as air or water, it can be bent or refracted. This refraction causes the different colors of light to separate, resulting in the formation of a rainbow.

Dispersion of Light Explained:
When light enters a medium, such as a raindrop, it slows down and changes direction. This change in direction is known as refraction. However, different colors of light have different wavelengths, and as a result, they are refracted at slightly different angles.

Prism Effect:
The phenomenon of dispersion is similar to what happens when light passes through a prism. A prism can split white light into its constituent colors, creating a spectrum. Similarly, when light enters a raindrop, it undergoes multiple internal reflections and refractions, causing the different colors to separate and form a circular arc of colors.

Formation of a Rainbow:
To see a rainbow, three conditions must be met:
1. There must be raindrops in the air.
2. The sunlight must be shining from behind the viewer.
3. The viewer must be positioned between the sun and the raindrops.

When sunlight passes through raindrops in the air, the light is refracted, reflected internally, and refracted again as it exits the raindrop. This causes the different colors of light to spread out and form a circular arc. The red color is always on the outer edge of the arc, while violet is on the inner edge, with the other colors in between.

Explanation of Colors:
The separation of colors in a rainbow is a result of the different wavelengths of light. Red light has the longest wavelength, while violet light has the shortest. This is why red appears on the outer edge of the rainbow and violet on the inner edge.

Conclusion:
In conclusion, the formation of a rainbow is a result of the dispersion of light. When sunlight passes through raindrops, the different colors of light separate and form a circular arc of colors. This natural phenomenon adds beauty to the sky and is a fascinating sight to behold.