Time crystals? No, I had not hears of them either, before reading this: https://www.iqsdirectory.com/resources/time-crystals-a-new-form-of-matter-that-could-change-everything/
“Time crystals are systems of atoms that arrange themselves in time the way more traditional solids crystallize in space. In case your brain isn’t bent enough trying to figure out what that means, the two groups of scientists created radically different structures that both fall under the label “time crystals.” These atomic arrangements are not time travel portals or infinite Rube Goldberg Machines, but rather the advent of a whole new state of matter–independent from the familiar solids, liquids, and gases that comprise our known universe. MIT theoretical physicist Frank Wilczek first proposed the idea of time crystals in 2012, positing that if properties change over time rather than in space that it might create new states of matter. Less than six years later, the two groups of scientists created crystals that seem to possess properties similar to those he proposed.