Zheng Deng

An ordinary wire heats up when current flows through it — some energy is wasted. A superconductor lacks this flaw: electricity flows through it without loss, like water through a perfectly smooth pipe. The trouble is that most superconductors require either very low temperatures or colossal pressures, like those found in the depths of planets.

A frozen orchestra where musicians swap seats when the conductor, magnetism, sets a new score. In a spinel crystal, iron and magnesium atoms sit in two types of seats: some surrounded by four neighbors, others by six. At room temperature, they barely stir, but cool the material to 5 K and a mass migration begins.