Wave-Particle Duality in Classical Mechanics

TL;DR

This paper presents classical objects that exhibit both wave and particle features, challenging the notion that wave-particle duality is exclusive to quantum mechanics, and suggests quantum phenomena may emerge from deeper classical laws.

Contribution

It introduces a new family of classical objects displaying wave-particle duality without quantum prerequisites, and demonstrates quantum-like phenomena within classical Newtonian mechanics.

Findings

Classical objects can show interference, tunneling, and reflection.

Wave-particle duality can exist without oscillating fields or energy inflow.

Quantum phenomena may be approximated from classical mechanics.

Abstract

Until recently, wave-particle duality has been thought of as quantum principle without a counterpart in classical physics. This belief was challenged after (i) finding that average dynamics of a classical particle in strong inhomogeneous oscillating field resembles that of a quantum object and (ii) experimental discovery of "walkers" - macroscopic droplets that bounce on a vertically vibrating bath of the same fluid and can self-propell via interaction with the surface waves they generate. This paper exposes a new family of objects that can display both particle and wave features all together while strictly obeying laws of the Newtonian mechanics. In contrast to the previously known duality examples in classical physics, oscillating field or constant inflow of energy are not required for their existence. These objects behave deterministically provided that all their degrees of freedom are known to an observer. If, however, some degrees of freedom are unknown, observer can describe such objects only {\it probabilistically} and they manifest {\it weird} features similar to that of quantum particles. We show new classical counterparts of such quantum phenomena as particle interference, tunneling, above-barrier reflection, trapping on top of a barrier, and spontaneous emission of radiation. In the light of these findings, we hypothesize that quantum mechanics may \emph{emerge} as approximation from a more profound theory on a deeper level.