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

by Adam Becker

A contextual roulette wheel can exist—it’s just that the ball’s location will change when you look at it in different ways, because you can’t separate the behavior of the ball from its interaction with you when you look at it. That doesn’t mean the ball doesn’t exist or that it doesn’t have a location before you look; it just means the ball is kind of jumpy and sensitive, moving around dramatically at even the slightest disturbance. The hidden variables in Bohm’s pilot-wave interpretation behave in exactly this way. Particles, according to Bohm, always have positions—but those positions can be dramatically altered by small disturbances and changes in experimental setups. Ask a slightly different set of questions to an electron, in Bohm’s world, and you can get an enormously different set of answers—but the electron has a definite position all the while. And because Bohm’s theory is contextual, it evades all of the proofs that supposedly rule it out. “What is proved by impossibility proofs,” concluded Bell, “is lack of imagination.”