Mirror-positioning method could make quantum gravity tests possible

In quantum physics, objects can exist in multiple states at the same time—a phenomenon known as quantum superposition, where a particle does not have a single definite value of position or momentum until it is measured. A major open question is whether gravity, one of the fundamental forces, also follows the quantum rule. One way to examine this is through gravity-induced entanglement, in which two objects that interact only via gravity become quantum mechanically linked.