Scattering in water or atmosphere

[coke]

hi, i want to know why scattering can occur when the light beam meet the particle, dust in atmosphere or molecules in water ..., but why not when they meet the glass surface and let the electrons in the glass surface be scattered? can anyone kindly help me, and tell me more about this ? thanks very much.

 

[Andy Resnick]

There is scattering in both cases. In one, most of the light is forward scattered, while form another, there is considerable angular scattering.

There's no need to invoke atoms- simple geometry (size of beam vs. object) is sufficient.