Department of Physics and Materials Science

Infinity Mirror

See Into Infinity

Infinity mirrors are simple: mount lightbulbs on a regular mirror, then put a one-way mirror (like in interrogation rooms) in front.

In principle, two mirrors facing each other would reflect light back and forth forever. In reality, some of this light to escapes during each reflection (you couldn't see the bulbs otherwise ).

When the light emitted by the real bulb reflects off either mirror and enters our eyes, it appears to be coming from an "image bulb" that sits farther back than the real bulb.

Because some light escapes after each reflection, there is less left over to produce the deeper image bulbs, making them look dimmer.