Recent research by French physicists suggests maybe quantum particles are more than just a statistical construct and do actually exist even when not under observation. MIT math professor John Bush says the new research has convinced him that the long-out-of-favor pilot-wave theory should be given another look.

Pilot Wave Theory May Supplant Copenhagen Interpretation In Quantum Mechanics

Copenhagen interpretation vs pilot wave theory

The traditional Copenhagen interpretation says that quantum matter really only exists as a wave. The  Copenhagen interpretation bypasses the thorny problem of determining quantum matter’s trajectory by positing that it doesn’t exist as a particle except during the time it is under observation. Early 20th century physicists led by Louis de Broglie considered another explanation they called the “pilot-wave theory.” This theory held that quantum matter actually always exists as particles, but these particles are moved along by an unknown wave-like influence which makes them seem to exhibit wave-like behavior.

French pilot wave theory research

Researchers at the University of Paris Diderot have found a new  pilot-wave system existing on the macroscopic scale that still exhibits statistical behavior under specific conditions similar to the behaviors ascribed to quantum systems.

The French researchers used a basin of fluid vibrating at frequencies just below the point at which waves form on the surface. For the experiment, a single drop of the identical fluid was dropped into the basin, causing waves to propagate outward from the spot where it landed.

Surprisingly, the new droplet was carried across the basin by the very same waves it created.

Pilot Wave Theory: Statements from MIT Professor Bush

“This system is undoubtedly quantitatively different from quantum mechanics,” Bush says. “It’s also qualitatively different: there are some features of quantum mechanics that we can’t capture, some features of this system that we know aren’t present in quantum mechanics. But are they philosophically distinct?”

“The key question is whether a real quantum dynamics, of the general form suggested by de Broglie and the walking drops, might underlie quantum statistics,” he says. “While undoubtedly complex, it would replace the philosophical vagaries of quantum mechanics with a concrete dynamical theory.”