Question

I am still looking for an explanation for the lay reader on why clouds are white for the lay reader. I would like to understand the mechanism for interaction between the water molecules in the cloud droplet and the wavelengths of visible light. I understand the idea of scattering (Rayleigh, Mie, and geometric), how rainbows are formed inside a raindrop...but not how white light (photons) are scattered by a cloud droplet (electrons). I am not sure I am asking the right question or which branch of Science to turn to for an answer...meteorology, chemistry, quantum mechanics??

Answer 1

walter lewin's return lecture after his retirement, which he did as part of the promotion of his new book, gives a beautiful explanation as to why this happens; something about how the water droplets in the clouds are no smaller than a certain size, which i cant remember off the top of my head, thus reflecting all of the colors of the individual light bands that make up white light. whereas, water vapor in the atmosphere is about .5microns or smaller therefore, only the blue bands get scattered which is why the sky is blue. something like that, i dont remember the numbers exactly. hope you find the answers you were looking for.

Answer 2

the clouds appear white due to diffused reflection

Answer 3

diffused reflection is due to large size of droplets