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How does Wi-Fi travel through walls?

You watch a video in your bedroom. But the Wi-Fi router is in the living room — behind a wall! How does the signal reach you?

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In this lesson you will discover the secret of invisible waves — and even learn where the best spot for a router is in an HDB flat. Let's go! 🚀

Wi-Fi is an invisible wave 🌊

Wi-Fi carries messages using radio waves. They are a kind of light your eyes cannot see. They zoom through the air at amazing speed — no wires needed!

Wave spotter: One of these also sends messages with invisible radio waves. Tap it!

💡 Torchlight is a wave you can see, and a drum makes sound waves. A radio uses invisible radio waves — just like Wi-Fi!

Walls are not solid to a wave 🧱

Sunlight passes through a glass window, right? Radio waves are even better at passing through things — they can slip through wood, glass, and even brick. But every material lets a different amount through.

Wall tester: Tap a material to build the wall and fire a Wi-Fi wave at it. Try all five!

wood
Pick a material to test! (0 of 5 tested)

Each wall makes the wave weaker 📉

When a wave passes through a wall, the wall soaks up a bit of its energy — like a runner getting tired after each hill. More walls between you and the router = weaker Wi-Fi.

Detective time: The router 📶 is in the living room. Which room will have the weakest Wi-Fi? Tap that room!

Living room 📶 0 walls away Bedroom 🛏️ 1 wall away Store room 📦 2 walls away
Tap a room to answer

Some things bounce the wave away 🪞

Radio waves slip through wood and brick, but metal is like a mirror to them — the wave bounces off! Thick concrete and even big tanks of water soak up lots of the wave too.

metal No entry! ⛔
🇸🇬 That's why Wi-Fi struggles near a metal fridge, inside a metal cabinet, or through the thick concrete walls between HDB units!

Fun fact: your body is mostly water — a room full of people can weaken Wi-Fi a little too!

Be the Wi-Fi engineer! 🛠️

Your family just got a new router. Using everything you learnt, tap the best spot for it in this flat.

Kitchen Bedroom Bathroom Living room (middle of home) 🧊 A B C D
A: next to the metal fridge · B: open shelf, middle of home · C: inside the bathroom · D: floor corner of the bedroom
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Wi-Fi wizard!

Amazing work! Here's what you discovered today:

🌊 Wi-Fi is an invisible radio wave — a kind of light your eyes can't see.

🧱 Waves can pass through walls — like sunlight through glass, just invisible.

📉 Every wall soaks up some energy — more walls means weaker signal.

🪞 Metal bounces waves away, and thick concrete and water soak up lots.

🏠 The best router spot is open, high up, and near the middle of your home.

Next time your video loads slowly, you'll know exactly why — count the walls! 😄📶