New Experiment Rules out Bohmian Mechanics. It’s Serious.

Quick Overview

A new experiment has experimentally ruled out Bohmian mechanics, a long-standing interpretation of quantum mechanics that posits point-like particles guided by a wave, by demonstrating that tunneling photons exhibit non-zero velocity, directly contradicting Bohmian mechanics' prediction of zero velocity for such particles.

Key Points: Bohmian mechanics, a century-old interpretation of quantum mechanics, has been experimentally ruled out after 70 years of debate. Standard quantum physics describes everything by a wave function, which is unobservable and used to calculate probabilities, making it a non-deterministic theory. David Bohm's interpretation, Bohmian mechanics, posits point-like particles guided by a wave, where the wave function is split into a guiding field equation and a particle equation. In Bohmian mechanics, observations are probabilistic due to a lack of knowledge about the particle's initial position, but the particles themselves are considered physically real. A new experiment used photons traveling in a microcavity with a waveguide and a second adjacent guide to observe quantum tunneling. The experiment measured that tunneling photons spread from their point of appearance, indicating they possessed non-zero velocity, which directly contradicts Bohmian mechanics' prediction of zero velocity for such particles. This result is incompatible with Bohmian mechanics but aligns with the standard Copenhagen interpretation of quantum mechanics.

Context: Quantum mechanics, over a century old, has long been debated regarding its interpretation, particularly concerning the nature of particles and their behavior. One prominent interpretation, Bohmian mechanics (also known as pilot-wave theory), proposed by David Bohm about 70 years ago, suggests that quantum mechanics describes point-like particles that are always at a definite position and follow a guiding wave. This deterministic view contrasts with the standard Copenhagen interpretation, which describes particles probabilistically via a wave function, leading to a non-deterministic theory.