Video narration
Why does your face seem behind the bathroom mirror when nothing is there? Light from your face hits the mirror and reflects into your eyes. Your brain traces rays backward, so the image seems to come from behind the glass. The mirror sends no light behind it; it only creates a virtual image, which cannot be projected onto a screen. Two laws explain reflection. First, the incoming ray, reflected ray, and normal-the imaginary line perpendicular to the mirror where the ray hits-lie in one plane. Second, the angle of incidence equals the angle of reflection. Measure both from the normal, not the mirror. A plane mirror forms an upright, same-size image, equally far behind it as your face is in front, and laterally inverted-left and right reversed. So your face seems behind the mirror because reflected light reaches your eyes, making it seem to come from there.