You have a light bulb in the middle of a room and ....... Hi people, heres an easy question for you. I was asked this by a guy down the pub a few days ago, I think I know the answer, but they don't believe me. If you have a light bulb switched on in the middle of a room and then you put mirrors on the walls is there any more light in the room or does there just appear to be more light in the room, but actually there is no more light in the room ? Please state your reasoning and qualifications to answer this question. I have a degree in Physics and they don't believe me so why should they believe you ?