Brian Skinner remembers getting back from a weekend bachelor party and hearing about the paper. “Everyone was talking about it,” says Skinner, a postdoc at Massachusetts Institute of Technology. It was posted on the physics preprint server arXiv and described a silver-and-gold nanostructured material that acted as a superconductor at 236 K, or –37.15 °C, and ambient pressure. That claim was remarkable. Superconductors are materials with zero electrical resistance, meaning an electrical current flows through them with no energy loss. They’re used to produce the powerful electromagnets in magnetic resonance imaging and nuclear magnetic resonance machines, as well as in particle accelerators. Existing superconductors, however, work at very low temperatures. The superconducting niobium-titanium wires used in many MRI machines sit in a 4 K (–269 °C) bath of liquid helium, for instance. A material that acted as a superconductor at ambient temperatures (closer to 293 K) and pressures could revolutionize