A plain-English tour of how a battery can make, dial, and flip a magnet β and why that turns our tiles into real physics.
Here's the one idea everything else hangs on: a moving electric charge makes a magnetic field. That's not a coincidence or a trick β electricity and magnetism are literally the same phenomenon seen from two angles. Physicists call the whole thing electromagnetism. Once you feel that in your hands, the rest is just turning knobs.
In 1820 a teacher named Γrsted was demonstrating a battery and noticed the compass needle on his bench twitch every time he switched the current on. A wire with electricity flowing through it was pushing a magnet around. No magnet in the wire β just moving charge. That twitch is the whole science in miniature: run a current, and a magnetic field wraps around it.
One straight wire makes a weak, wrap-around field. But coil the wire into a loop, and then into many loops (a solenoid), and every loop's field points the same way down the middle β they stack. Now you have a bar magnet with a clear north and south end, made entirely out of electricity.
Drop a plain iron nail into the middle of the coil and the field gets dramatically stronger β the iron lines up with the field and adds its own. That's an iron core, and it's why a small coil can lift a car in a scrapyard.
Because it's just electricity, you own every dial:
β‘ On / off β cut the current and the magnetism is simply gone.
ποΈ Strength β turn the current up or down (a knob, or a chip pulsing it) and the pull grows or fades smoothly. A continuous dial of magnetic charge.
π Polarity β reverse the current's direction and north and south swap. The same tile can pull, then push, on command.
A permanent magnet β a fridge magnet β can do none of this. Its strength and its poles are frozen in. An electromagnet is a magnet you can conduct, like an instrument.
There's one catch with a plain electromagnet: it only holds its grip while the current flows, which drains the battery and makes heat. The elegant fix already exists, and it's beautiful.
An electropermanent magnet (EPM) pairs two permanent magnets β one "soft" (easy to re-magnetize) and one "hard" (stubborn) β with a coil around them. A brief pulse of current flips the soft one. When the two magnets point the same way, their fields add up β the magnet is ON. Pulse it again and the soft one flips back so they cancel β OFF. And here's the payoff: it holds that state with zero power. No steady current, no heat β just a tap to set it, and it stays.
When you pop a small coil into each tile, the player isn't pretending. They're setting a current to set a magnetic strength, reversing it to flip a tile, and watching real magnetic force snap pieces together or spin them around. Dial a stronger charge and your tile wins the tug-of-war against a weaker one across the board. That's electromagnetism you can feel β the same thing the on-screen MagnetismLab teaches, now living in your hands.
You've been building a game. It turns out you were building a physics lab that happens to be fun.
That's the whole shape of it. Everything fancier β motors, generators, transformers, the radio in your pocket β is this same one idea, arranged cleverly.
β Designee