A physics teacher walks 4 meters East, 2 meters South, 4 meters West, and finally 2 meters North. What is her distance and what is her displacement.

When you see distant streetlights through smog, they look dimmer and redder than they do normally. but when you see the same streetlights through fog or falling snow, they look dimmer but not redder. use your knowledge of the interstellar medium to discuss the relative sizes of the particles in smog, fog, and snowstorms compared to the wavelength of light.