Sir, 1) A thick plane mirror shows a number of images of the filament of an electronic bulb. It is said that of these images the first image is the brightest. Is it true? If so, is it because some energy is lost in traversing through the dense medium? 2) It is said that the intensity of light at a large distance r from a long, thin cylindrical source of light is proportional to r^0. Is it true? I know that intensity of a point source is proportional to r^(-2). In what way is a long, thin cylindrical source of light different? Can't the cylindrical source be treated as a point source for large distances? Here the symbol ^ stands for power.