Atomic Mouse Probes the Lifetime of a Quantum Cat

How do you detect a Schrödinger's cat—an object that straddles two quantum states at once, like a cat that is both dead and alive? You let a mouse run past its nose and see what happens to the mouse. Physicists have now done the experiment with a microwave field (the cat) in an indeterminate quantum state and an atom (the mouse) prepared so that it can react to the dead-and-alive state of the cat.