Question

why sky appears blue not red??????

Answer 1

Any particle we see is of the colour whose wavelength is less that the diameter of the particle.The blue color of the sky is due to the dust particles which are of small size.Had they been of a larger size,the sky would have appeared blue.

Answer 2

A clear cloudless day-time sky is blue because molecules in the air scatter blue light from the sun more than they scatter red light. When we look towards the sun at sunset, we see red and orange colours because the blue light has been scattered out and away from the line of sight.