Optics Science Demo: Parabolic Mirrors Explained

Optics can make you see what isn’t really there. In this optics science demo, Museum Educator Locke explores how two parabolic mirrors can create a virtual image that looks so real, it fools your eyes—but there’s nothing actually there to touch.

Using the principles of light reflection, this demo shows how light from a physical object (in this case, a LEGO) reflects off the curved surface of a parabolic mirror, then bounces through a second mirror, converging at a focal point. What appears above the mirrors is a 3D image that hovers in space—fully visible, but impossible to grab. This isn’t magic—it’s physics.

In optics, this phenomenon is called a virtual image: a reflection formed by light rays that appear to come from a location but don't actually converge there. These mirrors take the idea of everyday reflections to the next level, creating an interactive visual experience that challenges how we perceive light and depth.

This is one of many engaging ways to demonstrate the power of physics and the fascinating behavior of light!