These are the words of researchers from the CNR, Italy’s National Research Council, summing up an extraordinary experiment recently published in Nature: a supersolid made of light. A quantum material that defies all known categories, behaving simultaneously like a solid crystal and a frictionless fluid.

Until yesterday, we could only imagine such exotic states of matter using ultracold atoms. Today, thanks to a team of physicists from the Italian National Research Council, light itself has been transformed into this paradoxical state, opening the door to a new chapter in fundamental physics—and perhaps even to technologies we can’t yet begin to imagine.