What is atmospheric refraction? Use this phenomenon to explain natural events. (a) Twinkling of stars (b) advanced sunrises and delayed sunset. Draw diagrams to illustrate your answer
Answers
Explanation:
Atmospheric refraction is the deviation of light or other electromagnetic wave from a straight line as it passes through the atmosphere due to the variation in air density as a function of height. ... Astronomical or celestial refraction causes astronomical objects to appear higher above the horizon than they actually are.
In reality stars do not twinkle but it appears to twinkle when seen from the surface of the Earth.
Twinkling of stars take place due to atmospheric refraction. In simple terms, twinkling of stars is caused by the passing of light through different layers. These layers have different densities and temperatures. Due to this, light rays bent (refracted) many times in random direction.
As a result stars appear to twinkle
When the light rays pass through the atmosphere having layers of different densities and refractive indices, then refraction of light takes place. This refraction of light by the earth's atmosphere is called "atmospheric refraction".
E.g. At sunrise and sunset the light coming from the sun has to travel a longer distance through the atmosphere to reach us. Therefore the blue and green components of white light are gets scattered away (removed) almost completely leaving the longer wavelength. Hence, during sunrise and sunset the sun appears reddish.