Avery long cylinder of linear dielectric material is placed in an otherwise uniform electric field e0. find the resulting field within the cylinder. (the radius is a, the susceptibility χe, and the axis is perpendicular to e0.)

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.