The experimental setup is simple: just a liquid-filled beaker surrounded by a magnet. That magnet is hooked up to alternating current, which creates a magnetic field that can flip direction very quickly. Most of the time, when the scientists sprinkle particles into the liquid and turn on the current, nothing really interesting happens. Maybe the particles link together in static strings. But when the magnetic field is tuned just right, something strange happens. The particles snap into chains that just start swimming around.
"We call this structure Snake," Snezhko says, pointing to one of the simple structures, and indeed, it looks like that game you used to play on your pre-iPhone Nokia. (You can see
a slew of other clips of the snakes at Wired Video.)
The snakes' motion, Snezhko says, is a kind of "
resonance." As the magnetic field flips back and forth, the particles' movement changes the surface of the water, which changes how the particles move, which changes the surface of the water, and so on. The simulation they've developed, in the video below, helps show how the process starts.
