Misinference of interaction-free measurement from a classical system

TL;DR

This paper demonstrates a classical analog of interaction-free measurement using a hydrodynamic system, challenging the quantum interpretation that such measurements are inherently interaction-free.

Contribution

It introduces a classical hydrodynamic system that mimics interaction-free measurement, questioning the quantum exclusivity of this phenomenon.

Findings

Classical hydrodynamic system can replicate aspects of interaction-free measurement.

Measurement in the system involves interaction, contrary to quantum interpretation.

Classical explanation challenges the notion of truly interaction-free quantum measurements.

Abstract

Interaction-free measurement is thought to allow for quantum particles to detect objects along paths they never traveled. As such, it represents one of the most beguiling of quantum phenomena. Here, we present a classical analog of interaction-free measurement using the hydrodynamic pilot-wave system, in which a droplet self-propels across a vibrating fluid surface, guided by a wave of its own making. We argue that existing rationalizations of interaction-free quantum measurement in terms of particles being guided by wave forms allow for a classical description manifest in our hydrodynamic system, wherein the measurement is decidedly not interaction-free.