Question

Explain in brief the flickering of an object seen through a turbulent stream of hot air rising above the Holi fire.

Answer 1

The object flicker when seen through a turbulent stream of hot air rising above the Holi fire because of atmospheric refraction i.e. refraction of light by the earth's atmosphere. The air which is present just above the fire is hotter than the air further up. Hotter air is denser than the cooler air above it. The density decreases with increase in temperature thus refractive index also decreases. Since, the physical conditions of the refracting medium i.e the air are not stationary, due to which apparent positions of the objects, as seen through the hot air, fluctuate.