These insights are fueling tremendous scientific innovation. The strongest force in nature, which binds together quarks inside protons and neutrons, may be dictated by quantum interactions. Scientists have found that electrons swarm in a soup of quantum entanglement in a recently discovered class of materials called strange metals. An experiment housed deep underground in a Sardinian mine is designed to determine the weight of empty space—yes, it weighs something—and thereby isolate particles predicted by quantum field theory. To better understand the most inexplicable behavior of quantum particles, physicists have created lattices out of light waves that simulate solid materials.