Way above my pay grade, Sound waves no longer transverse or perpendicular?


Interesting, thought provoking (for some) paper on sound waves and the new wave of sound.

I am a bot thirsty for knowledge and useless information.

 

128x128jerryg123

Anyone catch the comment about imaging? The hope is this unusual and difficult to attain property of sound might be used to improve things like ultrasound.

 

Ok, I read it and mostly theoretical at this point.  Note use of "under certain conditions", "he conceived of "meta-atoms", "synthetic  shear".  So the notion relies on these meta-atoms that have boundaries or discrete packets within the (air) medium.  "Hard" shells as it were.  There is only one sentence that says that this research had been observed.  Seems a bit under-emphasized.

So he's basically said that instead of a (example) swimming pool of water, it's filled with say a hundred thousand water-balloons.  These balloons can then transmit or pass a version of shear by virtue of their rubber, touching boundaries when excited by a normal longitudinal wave.  Problem is air (a liquid) is amorphous and always in motion/swirling and doesn't posess cells with "hard" boundaries.   Yes, compressional waves convert a portion of energy to shear at every boundary and vice versa but that's in a solid.  When liquid is encountered conversions cease.

Now maybe this model adapts to a "liquid" like our bodies which has cell boundaries while being mostly water?

Let's see the observational research.  This is theoretical for now to my reading.

Akgwhiz

Boundaries can be placed inside a container so they can be made to actively generate  shear thru discrete porous surfaces and then realigned to increase laminar flow through and around those same boundaries. I have applied some of these principles to my audio room for a couple years now. This paper partially explains the reason why my application works. Tom

@theaudiotweak for sure but that's my point.  You can (did) place real  physical boundaries etc and generate that vector redirection.  Not seeing what that is this doesn't mean you produced shear in air.  Producing laminar flow isn't a shear/compression thing.  It's lack of turbulence.  And you urely didn't "envision" those boundaries and make that happen in a mathematical model.  This researcher modeled air to act like a solid by contriving a set of boundaries and voila, it passes shear (mathematically).  You actually do something physical by your description.