Making waves: new study proves long-standing physics theory

5 June 2018
An international team of researchers, led by the University of Sydney, has used the famous 'Schrödinger equation' to prove the existence of a wall phenomenon impacting on the physics of waves.
Experiments conducted in a water wave facility

Photographs from experiments conducted in a water wave facility show the existence of domain walls.

In a new study published in the American Physical Society’s journal Physical Review Letters – one of the most prestigious journals in the field of physics – the interdisciplinary group of researchers from the University of Sydney, Hamburg University of Technology and Imperial College London has proven the existence of ‘domain walls’ for water waves, which are commonly visible as water ridges or swell on the surface of a body of water.

“Similar to the way a physical wall separates a space into two separate rooms, domain walls separate two different physical and dynamical wave processes,” said the study’s lead author Associate Professor Amin Chabchoub, an expert in environmental fluid mechanics from the University of Sydney’s Faculty of Engineering and Information Technologies.

In the new study, the research team used controlled experiments to show that non-linear domain walls can be constructed to split apart surface gravity water waves.

“The question of the existence of domain walls between waves on deep water has been investigated since the 1960s,” said Associate Professor Chabchoub.

Our research proves, for the first time, that the dynamics of water waves are not only of chaotic nature, but can be also ordered with clear existing physical boundaries.
Associate Professor Chabchoub
A graph of domain wall in water waves.

Domain wall in water waves: experiments (blue lines) and theoretical predictions (red lines).

The study marks the first time that experiments to test this theory have been conducted in a water wave facility, in this case a ship model testing facility in Hamburg.

The researchers used the famed and universal non-linear Schrödinger equation to model the domain walls in a higher-dimensional water wave process.

“The experimental results clearly show the domain wall separating two water wave states,” said Associate Professor Chabchoub.

Associate Professor Chabchoub said the study could have a significant impact in various science and engineering disciplines, namely in optical and plasma physics, electrical engineering, medical engineering and ocean engineering.

Related articles