Q: Why sun looks red at time of sunrise and sunset ?
Sol: Light from the sun near the horizon passes through thicker layers of air and larger disgrace in the earth’s atmosphere before reaching our eyes. However in the overhead position. Light from the sun travel relatively shorter disgrace. At noon, the sun appears white as only a little of the blue and violet colours are scattered. At the time of sunset and sunrise (near the horizon), most of the blue light and shorter wavelengths are scattered away by the particles. Therefore, the light that reaches our eyes is of longer wavelengths. Hence the sun looks red both at time of sunrise and sunset.