A collection of papers that use or involve acoustics that are not just another application….
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Supersolid-like sound modes in a driven quantum gas - Nature Physics
Research at the Uni Heidelberg has shown that by feeding a small amount of energy into a superfluid, sound waves propagate at two different speeds, which points toward coexisting liquid and solid states, a hallmark of supersolidity
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Audible sound decreased beer fermentation time with minimal effects on the abundance of volatile organic compound production - Food Research International
Sound makes beer ferment faster….we need more research like this!
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Vertical orientation in mesopelagic fishes…
Many of us know that TS-length models for myctophids and biomass estimations of deep-scattering layers remain elusive due to numerous uncertainties. With the exception of fish that are ensonified at-or-near resonant frequency, orientation angle should impact TS measurements. Are we underestimating mesopelagic fish biomass because many of them are actually looking upward?
I haven’t seen this behavior discussed much in recent literature, so I found this paper from the Proceedings of an International Symposium on Biological Sound Scattering in the Ocean hosted by the US Navy in 1970 “Deep Sea Fishes Lethargy and Vertical Orientation” by Eric Barham.
Turns out myctophids spend a good deal of their day at certain depths looking up. Observers found that they don’t move much. No tail beating, just opercular opening and closing (could contribute to variability in TS?)
Other than a Costeau-style diving saucer, does anyone have a good method for measuring the orientation of these fishes undisturbed in-situ? In the same vein, can we then apply these orientation distributions to biomass estimation for global scattering layers similarly as has been applied for krill?
Paper cites found on pages 100-118.
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