So new coverage of the previous research I had blogged on.
Esposito suggests [others] may have overlooked the effect because they rarely think about interactions with gravity. But he and his colleagues are high-energy physicists. “I think it helped us to have a different mindset.”...
The team says that their analysis revealed the effect because it goes beyond the simplified linear models....
The mass carried by sound waves turns out to be negative. It is a depletion of mass, rather an addition of mass.
For ordinary sound waves in most materials, the mass carried is equal to the sound wave energy multiplied by a factor that depends on the speed of sound and the medium’s mass density.Yet this new phenomenon still relies on classical physics:
The theory assumes Newtonian conditions, so the effect is unrelated to either quantum theory or the equivalence of energy and mass known from [special] relativity.
Gravitational Mass Carried by Sound Waves
Angelo Esposito, Rafael Krichevsky, and Alberto NicolisPhys. Rev. Lett. 122, 084501 (2019)
Published March 1, 2019
I thought this was already published - it must have been a PrePrint when I blogged on it already.
Last year, high-energy physicists Alberto Nicolis of Columbia University in New York and Riccardo Penco, now at Carnegie Mellon University (CMU) in Pittsburgh, used quantum field theory to analyze the behavior of sound waves moving through superfluid helium [1]. To their surprise, they found that the waves carry a small amount of mass, not only by virtue of Einstein’s famous formula equating energy with mass. The duo found that phonons, the quantum units of sound waves, interact with a gravitational field in a way that requires them to transport mass as they move.Oh so this is a follow up study....
“It’s honest-to-God gravitational mass, the one we experience every day,” says team member Angelo Esposito of the Swiss Federal Institute of Technology in Lausanne (EPFL). “It is simply a fraction of the total mass of the system that travels with the wave, being displaced from one place to another.”
So sound waves in a gravitational field should float upward somewhat, like any buoyant object in water.So this again is only using classical math and not quantum noncommutative phase math. So now "acoustic holographs"
The basis of holography is spatial storage of the phase and/or amplitude profile of the desired wavefront5,6 in a manner that allows that wavefront to be reconstructed by interference when the hologram is illuminated with a suitable coherent source.
The complex three-dimensional pressure and phase distributions produced by these acoustic holograms allow us to demonstrate new approaches to controlled ultrasonic manipulation of solids in water, and of liquids and solids in air. We expect that acoustic holograms will enable new capabilities in beam-steering and the contactless transfer of power, improve medical imaging, and drive new applications of ultrasound.
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