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

by Adam Becker

Quantum physics—the physics of atoms and other ultratiny objects, like molecules and subatomic particles—is the most successful theory in all of science.

Quantum physics doesn’t seem to apply to humans, or to anything at human scale. Our world is a world of people and keys and other ordinary things that can travel down only one path at a time. Yet all the mundane things in the world around us are made of atoms—including you, me, and Danish princes. And those atoms certainly are governed by quantum physics. So how can the physics of atoms differ so wildly from the physics of our world made of atoms? Why is quantum physics only the physics of the ultratiny?

Yet, when it comes to quantum physics, the majority of physicists are perfectly willing to abandon this quest and instead merely “shut up and calculate,” in the words of physicist David Mermin.

But science is about more than mathematics and predictions—it’s about building a picture of the way nature works. And that picture, that story about the world, informs both the day-to-day practice of science and the future development of scientific theories, not to mention the wider world of human activity outside of science.

Quantum physics works, but ignoring what it tells us about reality means papering over a hole in our understanding of the world—and ignoring a larger story about science as a human process. Specifically, it ignores a story about failure: a failure to think across disciplines, a failure to insulate scientific pursuits from the corrupting influence of big money and military contracts, and a failure to live up to the ideals of the scientific method. And this failure matters to every thinking inhabitant of our world, a world whose every corner has been reshaped by science. This is a story of science as a human endeavor—not just a story about how nature works but also about how people work.

Born’s book, Natural Philosophy of Cause and Chance, made quite an impression on Bell—especially the discussion of a proof by the great mathematician and physicist John von Neumann. According to Born, von Neumann had proven that the Copenhagen interpretation was the only possible way of understanding quantum physics.