A rainbow is a beautiful natural phenomenon that occurs when sunlight interacts with water
droplets in the air.
Formation of a Rainbow:
1. *Sunlight*: Sunlight enters the Earth’s atmosphere and hits water droplets in the air, such as after
a rain shower or near a waterfall.
2. *Refraction*: The sunlight is refracted, or bent, as it passes through the water droplets.
3. *Dispersion*: The refracted light is split into its individual colors, a process known as dispersion.
4. *Internal Reflection*: The light is reflected off the back of the water droplet and passes through
the droplet again.
5. *Refraction (again)*: The light is refracted again as it exits the water droplet.
Curvature of a Rainbow:
1. *Circular Arc*: A rainbow appears as a circular arc because the water droplets are typically
spherical and the sunlight is refracted and reflected in a circular pattern.
2. *Angle of Deviation*: The angle at which the sunlight enters the water droplet and is refracted
determines the position of the color in the rainbow.
3. *Circular Shape*: The combination of refraction, dispersion, and internal reflection creates the
colorful, curved shape of a rainbow.
Why Rainbows Appear Curved:
1. *Geometry of Refraction*: The curvature of a rainbow is a result of the geometry of refraction and
reflection within the water droplets.
2. *Consistent Angle*: The consistent angle of refraction and reflection creates the circular shape of
the rainbow.
In summary, a rainbow is formed through the interaction of sunlight, water droplets, and air,
resulting in a beautiful, curved display of colors.