Nope, it’s not a story about Michael Jackson. That’s not how we do things around here. This is all about science.
Have you ever really thought about how mirrors work? Of course, on the surface it seems like an easy question to answer: the shiny surface behind the glass reflects your image back to you. But how exactly does that image get to the shiny surface and “bounce” so that we see a reversed version of ourselves? Why doesn’t the mirror reflect us upside-down as well as laterally inverted? The simple answer is that all light is energy, traveling very rapidly. The light that hits every object can pass through, be absorbed, or reflect. When light is present – either daylight or artificial light – it bounces off of everything in its vicinity. When you stand in front of a mirror, some of the light that bounces off of you will in turn bounce to the mirror and then back to your eyes.
In this video, the late physicist Richard Feynman explains why our reflections are laterally inverted but not upside-down. The physicist was known for his playful approach to life and to work, and this video is a great example of his free spirit nature. Taken from a 1983 appearance on the BBC program “Fun to Imagine,” the segment explains the mirror question in a very broad but understandable way.