Physicists have for the first time measured how our “perfect” fluid travels soundwaves to the nearest object, in an ideal case where the liquid is only defined by its density and pressure. This can further help the researcher to study and understand the interior of the neutron star and the extreme environment like the first few fractions of one second after the Big Bang. You can think of fluid as just a liquid, but the fluid is a substance that adheres to its container (research on whether cats are liquid won the IG Nobel Prize in 2017), including gas and plasma. The three fluids experience friction in their layers; the higher the friction, the thicker or viscous the liquid.
The MIT team has created a perfect liquid using Fermi gas. It is a specific state of matter where each structural element is fermions, into a specific class of particles that include electrons, protons, and neutrons. Firms do not like to interact with each other because of the quantum mechanical laws, but it is possible to force them to interact, reporting in Science.
To create a sound wave, the team varied the brightness of one side of the box. It creates mechanical waves through the gas. They recorded these thousands of snapshots to let them know which soundwaves were the most broadcast, the resonance frequency. As a result, the liquid has very little viscosity, or very little friction, an important step towards what is known in physics as a perfect liquid when this happens. The team firmly used fermionic atoms and used lasers to trap the gas and create an optical box. If an atom moves to one side of the box, the laser light can return it.
Senior author Professor Martin Zwierlein said in a statement, “All of these snapshots together give us a sonogram and that’s what happened when we took the ultrasound to the doctor’s office.” “Resonance properties tell me about the viscosity or sound uniqueness of a liquid. If the viscosity of a liquid is low, it can produce very strong sound waves and can be very loud, if only hit at the right frequency. If it’s a very viscous liquid, it doesn’t resonate well. “
The distribution of resonance frequencies gives a way to calculate the sound amplitude of their fluid. This is where things got very interesting. One of the most important basic physical constants for quantum mechanics is to obtain the same value using the mass of individual atoms and Planck’s constant. The properties of the liquid depend solely on the limits imposed by quantum mechanics. This gas was as perfect liquid as it could get.
Zwierlein added, “This function directly connects the resistance between the materials.” “Finding out what your minimum resistance to gas tells us what can happen to the electrons in materials and where to create materials where electrons can flow perfectly. It’s exciting.” Sound reproduction is definitely something: a bit like an old school sci-fi and a bit like an alarm. And it certainly needs a full explanation for the praise.