In a traditional Schrodinger’s cat experiment, you do not know whether the outcome of a quantum decay has occurred, leading to the cat’s demise or not. Inside the box, the cat will be either alive or dead, depending on whether a radioactive particle decayed or not. If the cat were a true quantum system, the cat would be neither alive nor dead, but in a superposition of both states until observed. However, you can never observe the cat to be simultaneously both dead and alive. (Credit: DHatfield/Wikimedia Commons)

Ask Ethan: What should everyone know about quantum mechanics? Quantum physics isn’t quite magic, but it requires an entirely novel set of rules to make sense of the quantum universe. The most powerful idea in all of science is this: the universe, for all its complexity, can be reduced to its simplest, most fundamental components. If you can…