Researchers from MIT have created the perfect fluid in a laboratory and managed to capture its sound.
To record the sound, the team of physicists sent a glissando of sound waves through a controlled gas of elementary particles called fermions.
The pitches heard correspond to the frequencies the gas resonates at.
Upon their experiment, the researchers found that the fluid’s sound diffusion was so low as to be described by a “quantum” amount of friction, given by a constant of nature known as Planck’s constant, and the mass of the individual fermions in the fluid.
These results are the first time scientists have been able to measure sound diffusion in a perfect fluid. This is because they do not commonly occur in nature but are thought to occur in the cores of neutron stars and in the plasma of the early universe.
“It’s quite difficult to listen to a neutron star,” Martin Zwierlein, the Thomas A. Frank Professor of Physics at MIT said in a statement. “But now you could mimic it in a lab using atoms, shake that atomic soup and listen to it, and know how a neutron star would sound.”
“This work connects directly to resistance in materials,” Zwierlein says. “Having figured out what’s the lowest resistance you could have from a gas tells us what can happen with electrons in materials, and how one might make materials where electrons could flow in a perfect way. That’s exciting.”