You don't normally associate any kind of sound with a magnet. But apparently that's because the ones stuck to your fridge aren't two million times as powerful as the Earth's magnetic field—like the one the Los Alamos Laboratory just created.
For over a decade and a half the lab has been trying to create a magnet with a strength of 100 Tesla that doesn't destroy itself in the process. And when they finally succeeded in hitting that level—at around the 1:36 mark in the video—the magnet emits a haunting scream instead of the electric hum you'd expect. If I worked in that lab every day I'd have nightmares every night.
While stronger man-made magnets have been created, they usually involve a destructive process, often using explosives, that makes them useless for any kind of actual research. But the 100 Tesla magnet at Los Alamos can be used again and again, making it ideal for scientific research, or ensuring the note you left on the fridge about remembering to buy milk will never, ever fall off. [Los Alamos via Dvice via Slashdot]