Why is the Sun seen a few minutes before it actually rises?
Open in App
Solution
Explanation:
When the light rays pass through the atmosphere having layers of different densities and refractive indices, then atmospheric refraction takes place.
The actual sunrise takes place when the sun is above the horizon. When the sun is just below the horizon, the light rays coming from it, on entering the Earth's atmosphere suffer atmospheric refraction from a rarer to denser medium.
So, they bend towards the normal at each refraction. Due to the continuous refraction of light rays at each layer, it follows a curved path and reaches the eye of the observer.
As a result, we can see the sun for 2 minutes before it rises above the horizon in the morning.