In the future, wires might cross underneath oceans to effortlessly deliver electricity from one continent to another. Those cables would carry currents from giant wind turbines or power the magnets of levitating high-speed trains.

All these technologies rely on a long-sought wonder of the physics world: superconductivity, a heightened physical property that lets metal carry an electric current without losing any juice.

But superconductivity has only functioned at freezing temperatures that are far too cold for most devices. To make it more useful, scientists have to recreate the same conditions at regular temperatures. And even though physicists have known about superconductivity since 1911, a room-temperature superconductor still evades them, like a mirage in the desert.