What Is Real?: The Unfinished Quest for the Meaning of Quantum Physics

by Adam Becker

Copenhagen interpretation states that quantum physics is merely a tool for calculating the probabilities of various outcomes of experiments.

Physics is the science of the material world. And quantum theory purports to be the physics governing the most fundamental constituents of that world. Yet the Copenhagen interpretation says that it’s meaningless to ask about what’s actually going on in quantum physics. So what is real? Copenhagen’s reply is silence—and a look of stern disapproval for having the temerity to ask the question in the first place.

While Mach believed that physics was merely about organizing perceptions of the world, to Einstein, physics was about the world itself. “Science,” he said, “has the sole purpose of determining what is.”