About This Lesson
You light a candle in a dark room. Now suppose a mirror is brought in. Is the room brighter? If you say no, you may find yourself battling your own intuition. Something in us wants to say there are now two sources of light. However, if you say yes, how can a mirror make there be more light than before? A mirror doesn’t make light. This is a great question because it forces us to rethink our immediate assumptions. As is often the case in science, the answer to the mirror puzzle is: it depends.