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Bounce Back: The Reflector Challenge

You only see a reflector when light comes back to your eyes. In eight short missions, use mirrors and corner reflectors to get the light where it needs to go, from someone walking home at night to the reflectors left on the Moon. Then try the bonus challenges, or build your own puzzle and share it.

The Reflector Challenge

Choose a level

Missions

Bonus challenges

Tap a square on the beam to place a mirror, tap again to turn it, and tap a third time to pick it up. On a computer you can also use the arrow keys and Enter. Your progress is saved on this device only.

Build your own puzzle

Pick a piece, then tap squares to place it. Tap again to turn lights, mirrors and splitters. Then check your puzzle can be solved and share the link.

The game is an illustration. Real mirrors, splitters and reflectors are never perfect, and some light is always lost.

How the light bounces

Why the eyes? You only see something when light from it reaches your eyes. That’s why reflectors are so useful: they send light from a headlight or torch straight back towards the person holding it.

Mirrors. When light hits a flat mirror, it bounces off at the same angle it arrived. That’s the law of reflection. The mirrors in the game sit at 45 degrees, so they turn the beam through a right angle.

Beam splitters. A beam splitter is a partly reflecting mirror. Some of the light passes straight through and the rest is reflected, which is how one light can reach two eyes.

Corner reflectors. Put mirrors together at right angles and light comes back out parallel to the way it went in, heading back towards where it came from. Bike reflectors and prismatic tape use tiny corner reflectors, and astronauts left large ones on the Moon. You can see how in How Reflective Tape Works.

Never shine a torch into anyone’s eyes, and never point a laser pointer at people, animals, vehicles or aircraft.

For teachers, clubs and parents

Bounce Back is free to use in lessons and clubs. It runs in the browser on phones, tablets and computers with nothing to download, and it doesn’t ask for names or save any scores online. Shared puzzles only contain the layout of the grid, so there’s no way to send messages through them. You’ll find more interactive activities, plus our tape calculators and guides, in the Learning Centre.

Bounce Back is made by Flashback Tape, a UK supplier of reflective tape.

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