Question

What is meant by atmospheric refraction of light? Explain the following natural phenomenon by using the concept of atmospheric refraction: (a) Twinkling of stars (b) Flickering of objects seen through a turbulent stream of hot air

Accepted Answer

1. **Atmospheric Refraction:** Refraction of light caused by Earth's atmosphere due to varying optical densities of air layers. 2. **(a) Twinkling of stars:** Starlight undergoes continuous refraction through atmospheric layers of varying refractive indices. The apparent position of the star fluctuates slightly, and the amount of starlight entering the eye continuously varies, giving a twinkling effect. 3. **(b) Flickering through hot air:** Air above a fire/heater is hotter and optically rarer than cooler air higher up. The physical conditions and refractive index of this air fluctuate rapidly, causing continuous random shifts in apparent image position.

Atmospheric refraction phenomena

Explanation

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