Question

Explain why

1. a) the sky is blue,

2. b) clouds are white, and

3. c) the underside of clouds sometimes looks gray.

Answer 1

Explanation:-

a) The sky is blue :-

                              A daytime sky is blue because in the air scatter blue light from the sun more than they scattered 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.

b) Clouds are white :-

                                   Clouds are composed of particles (dust particles, water droplets) which are large enough to scatter the white light that falls on them in such way that all the constitute colours of white light scatter as it is.since there is no variation among the scattering of different constitutes of white light and all of them are reflected back equally, the clouds appear white.

c) The underside of clouds sometimes loos grey :-

                                                                                      Clouds are in essence, massive collection of tiny water droplets and crystalline water molecules.

The colour of the cloud is created by reflected light as it passes through the water molecule, says Dr Jeff Kepert, head of high impact weather research at the Bureau of meteorology.

The droplets of water in a cloud are about a micrometre to a millimetre in size, and at the size, they scatter all wavelength of uniformly, he says.

“ so if you’re looking at light reflected from a cloud, which is normal situation, it will look white, but if you are actually looking upwards into the cloud, because there is a lot of light scattered in all direction, not much of it makes it through the cloud.so a thick cloud will tend to look grey on the outside and not have any distinct colour casts to it.”