“The aim of the study is to produce a platform that maintains a complete mathematical analogy with the Schrödinger equation, the main equation of quantum mechanics, but in a huge device that can be seen with the naked eye,” Rosenman explains. “The pool produces surface gravitational waves, which behave similarly to tiny material waves in the quantum world, thus allowing us to measure quantum phenomena in a macroscopic system. Theoretically there are phenomena in quantum mechanics that are very difficult to measure, and we found a way around this limit.”
Quantum mechanics is the name of a scientific theory that describes the world of particles at the subatomic level. One of the cornerstones of quantum theory is the dual description of physical bodies — both as particles and as waves. Similar to waves in the sea, quantum waves describe periodic oscillations in space and time, and are characterized by a phase, or an appearance. The phase of the wave determines whether at a certain point in space and time the wave will be at its peak of amplitude, at the lowest of amplitude or in any other intermediate state.
In 1927, the theoretical physicist Earl Hesse Kenard predicted that a quantum particle exerted on a constant force, such as a gravitational force on a mass-bearing body, or a constant electric field on an electrically charged particle, would accumulate a phase now named after him – the Kenard phase. In the 93 years since then, physicists have tried to think of creative experiments that would allow them to measure the phase of Kenard – but so far to no avail.
“We identified the equivalence between a quantum system that satisfies the Schrödinger equation and a hydrodynamic system of waves advancing on water,” Rosenman says. “In the second stage, we took this relationship one step further and built a system that maintains the Schrödinger equation and also exerts a constant force on the wave. By changing the forces, we can see with our own eyes how particles accumulate the phases predicted by Kenard theoretically. “There may also be practical uses, for example in the sensitive measurement of forces. These days we are using the wave pool to observe for the first time other physical effects, such as the phase accumulation of waves moving near black holes.”
The study was conducted, among others, by researchers from the schools of physics, mechanical engineering and electrical engineering at Tel Aviv University, in collaboration with researchers from the Institute of Quantum Physics in the hall in Germany.