I make two people out of one. What am I?

When you encounter a highly reflective surface, an identical likeness of yourself appears to stand before you. This optical phenomenon creates a visual duplicate, making it seem as though one person has become two within that moment. The surface acts as a portal, presenting an inverted yet accurate representation of whatever is placed in front of it.

The science behind this captivating illusion involves the behavior of light. Light rays traveling from your body strike the smooth, polished face of the surface. Instead of being absorbed, these rays bounce back, or reflect, in a highly organized manner directly into your eyes. Your brain then interprets these reflected light rays as an image located behind the surface, leading to the perception of a second individual. This reflected image is known as a virtual image, as the light rays do not actually converge at that point.

Humans have been fascinated by such reflections for thousands of years. The earliest known examples of these reflective objects date back to around 6000 BCE, made from polished obsidian in Anatolia. Later, ancient Egyptians and Mesopotamians created them from polished metals like copper and bronze. The advancement to glass with metallic backings, particularly refined in Venice during the Renaissance, significantly improved their clarity and accessibility, making them an integral part of daily life and scientific exploration.