Space and time looked settled, at least in broad outline. Einstein’s special relativity gave physics a durable framework for describing motion, and for more than a century one boundary seemed firm: light speed marked the edge of what any observer could cross. A new proposal asks what happens if that edge is not treated as a hard ban. In work published in Classical and Quantum Gravity, physicists argue that special relativity can be extended to include observers moving faster than light. The idea does not claim such observers have been found in nature. But it does suggest that throwing them out of the theory may have hidden something important, namely a possible link between relativity and the strange rules of quantum mechanics. The argument comes from Andrzej Dragan and Krzysztof Turzyński of the University of Warsaw, building on earlier work by Dragan and Artur Ekert, including the paper “Quantum Principle of Relativity” in the New Journal of Physics. Their latest study, “Relativity of superluminal observers in 1 + 3 spacetime,” keeps mathematical terms that are …