Scientists at MIT just discovered an entirely new state of magnetism in which the polarity of particles is constantly fluctuating. The new state, called a quantum spin liquid, had been predicted by theories before, but to prove it scientists had to grow this weird rock for 10 months.
The crystal is a mineral called herbertsmithite, which because of its bizarre magnetic state isn't fully behaving like a liquid or a solid. It's as if it can't make up its mind. According to MIT's news story about the scientists' new study in Nature:
The QSL is a solid crystal, but its magnetic state is described as liquid: Unlike the other two kinds of magnetism, the magnetic orientations of the individual particles within it fluctuate constantly, resembling the constant motion of molecules within a true liquid.
That probably makes your brain hurt.
Previously, there were only two known kinds of magnetism. Ferromagnetism, in which the polarity of particles all point in the same direction (as in a compass), and antiferromagnetism, in which the polarities cancel each other out. These two states work together to make hard drives possible, and the MIT researchers suggest that quantum spin liquids could have applications for computer storage and memory as well. [MIT via ExtremeTech]