By Sofia Pan, Grade 8
Nowadays, Wi-Fi is seen as something to be desired. You’ll probably find it harder to live without Wi-Fi than to live without food, but have you ever paused and wondered ‘What’s actually Wi-Fi?’
First, let’s clear something up. You might think Wi-Fi stands for “Wireless Fidelity.” It doesn’t. The underlying technology was actually called “IEEE 802.11b Direct Sequence”—try asking a bartender for that password. The Wi-Fi Alliance wanted something catchier, so they coined “Wi-Fi” as a pun on “hi-fi.” It’s a brand name, not a technical acronym.
So how does it work? Wi-Fi uses radio waves to transmit information between your device and a router. The two most common frequencies are 2.4 gigahertz and 5 gigahertz. A hertz is just a measurement of frequency. Imagine sitting on a beach, watching waves crash. One hertz equals one wave per second. One gigahertz equals one billion waves per second. Thank goodness beaches aren’t like that—it probably wouldn’t be too relaxing.
When you click on an article, your request is translated into binary code—a series of 1s and 0s. Your device’s Wi-Fi chip turns those 1s and 0s into wave frequencies. The router picks them up, converts them back to binary, and sends the request to the Internet through a cable. The whole process repeats in reverse to bring you the article you wanted. Most routers operate at 54 Mbps, meaning 54 million 1s and 0s are sent or received every single second.
Now, why can Wi-Fi pass through walls when visible light cannot? It comes down to frequency and wavelength. Visible light has an extremely high frequency and an extremely short wavelength. The atoms in your wall are excellent at absorbing waves of that size—so light stops. Wi-Fi operates at much lower frequencies with much longer wavelengths. Your wall’s atoms simply aren’t built to absorb waves that long. Instead of being stopped, most of the signal passes straight through.
When a Wi-Fi signal hits a wall, three things happen: part reflects, part is absorbed as a tiny amount of heat, and the rest travels through—weakened but still working. The thicker the wall, the more energy lost. But for most household materials, enough survives to keep you connected.
The real enemies? Metal and water. Concrete with steel mesh, metal shelving, and foil insulation bounce signals away almost entirely. A large aquarium or pipes inside a wall can also dramatically weaken your connection. Glass, wood, and standard plasterboard are far more forgiving.
From binary code to radio waves passing through solid walls, Wi-Fi is a quiet miracle of physics and computer science working together. And now, when someone asks for the password, you can tell them—it’s not just “IEEE 802.11b Direct Sequence.” It’s science.
