Communication with Light & Sound
Design and build a device that uses light or sound to solve the problem of communicating over a distance
What a learner can do afterwards
- Design a device that uses light or sound to communicate over a distance (e.g. string telephone, torch signals)
- Build and test the device, identifying what works and what could be improved
- Explain how the device uses properties of light or sound to transmit information
The lesson
You already know how light and sound work. Now you can use them to send a message to someone far away, without walking over there. A flashing torch sends a message with light. A tight string carries your voice in a string telephone.
Grab two paper cups and a long piece of string. Poke a small hole in the bottom of each cup, thread the string through, then tie a knot so it cannot slip out. Pull the string tight between two people. Talk into one cup: your voice makes the string shake, and the shaking string carries your voice all the way to the other cup.
After you build your device, test it and see what happens. A loose string telephone cannot shake well, so pull it tight. A dim torch is hard to see far away, so use a brighter light or move closer. Testing shows you what to fix.
Light travels in straight lines and sound travels along strings and air, so both can carry your message to someone far away.
Watch it
Where it sits
Learn first
This opens up
Where this leads
Jobs that lean on this skill. Follow one to see everything it is built on.
8 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.