Hey guys! I have some very basic questioins about light .. What exactly produces light? I know an incadescent light bulb has a filament that is basically a resistor that heats up, but why does it give off light? What is it that makes it put out the light? So that leads to the question ... what is light? I know it has dual nature of wave and photons, but does it have mass? And where does light go in a room? If you are in a brightly lit room and shut off the lights, where does the light that was in the room go? Is it absorbed by the surroundings? I dunno.. Just wonderig :) Thank you!