Bouncing
droplets (and the nature of reality)
Department of Mathematics
MIT
Yves Couder and coworkers have recently reported the results of a startling
series of experiments in which droplets bouncing on a fluid surface exhibit wave-particle duality
and, as a consequence, several dynamical features previously thought to be peculiar to the
microscopic realm, including single-particle diffraction, interference, tunneling and quantized orbits.
We explore this fluid system in light of the Madelung transformation, whereby Schrodinger's equation is
recast in a hydrodynamic form. Doing so reveals a remarkable correspondence between bouncing droplets
and subatomic particles, and provides rationale for the observed macroscopic quantum behaviour.
New experiments are presented, and indicate the potential value of this hydrodynamic approach to both
visualizing and understanding quantum mechanics.