Hydrodynamic Quantum Analogs

Pilot-wave dynamics of walking droplets

Yves Couder and co-workers have recently discovered that millimetric liquid droplets can spontaneously walk along the surface of a vibrating fluid and exhibit many features previously thought to be exclusive to the microscopic quantum realm. In certain parameter regimes, there is a breaking of symmetry: the drop destabilizes horizontally and starts landing on the slope of the central peak of its wave field, thus acquiring a horizontal impulse at each impact that propels it forward. A millimetric drop may thus walk steadily across the surface of a vibrating fluid bath by virtue of a resonant interaction with its own locally excited Faraday wave field.


This system has already attracted a great deal of attention from both the scientific community and the media, as it constitutes the first known and directly observable pilot-wave system of the form proposed by Louis de Broglie in 1926 as a rational, realist alternative to the Copenhagen Interpretation. Since the famous 1927 Solvay Conference, modern physics has, by and large, ascribed to the Copenhagen Interpretation, according to which the statistical theory of quantum mechanics (QM) is a complete description of physical reality, so that microscopic particles are intrinsically probabilistic. The resulting philosophical vagaries include the paradox of Schrödinger’s Cat, which reflects that microscopic particles are in an indeterminate state until observed. The quantum-like behavior of the walking droplets suggests a re-evaluation of de Broglie’s realist theory and the possibility of developing a deterministic quantum dynamics that would underlie the successful statistical quantum theory.


Here’s a couple of videos describing our research.

Through the Wormhole (Documentary on the Science Channel)

Video by Dan Harris and John Bush that summarizes some of our research