Re: How does fog affect how you see a light source

When a car shines the headlamps onto fog, both refraction AND diffraction 
should take place.  An observer standing inside the fog and looking at the 
headlamps will likely see a diffuse source.  Depending on the angle of the 
observer to the source, and the size of the suspended droplets, they may 
also see a rainbow (look up rainbow angle).

This is such an easy experiment, I highly recommend trying it next time 
you're standing in fog or in the clouds.