Scientists found a way to make sound travel in only one direction

https://www.zmescience.com/science/news-science/scientists-found-a-way-to-make-sound-travel-in-only-one-direction/

by Brajeshwar • 2 years ago

77 18 2 years ago

zmescience.com

pizzafeelsright2• 2 years ago

Audible laser?

Line of sight audio would be wonderful in a crowd.

DougN7• 2 years ago

I read the article and still don’t get it. Anyone want ELI5?

kylebenzle• 2 years ago

They used a concave disk-like speaker to produce sound. This solid shape makes the sound waves kind of spin around themselves like a tornado or one of those bubble rings you see people blow underwater [1] instead of a normal pressure wave that goes in all directions.

The tornado sound wave can only move forward and once it hits something is dissipated and doesn't reflect the sound.

1. https://youtu.be/t2kvEC852MI?si=QJjinL7AK6ZZS_SO

abetusk• 2 years ago

I've only skimmed the article/paper and I also dont' understand, so I'm just as ignorant as you, but there is such a thing as a Tesla valve that is a static object that allows water to flow in one direction [0]. I would assume that maybe they can make little vortices of air/liquid (as the comment by kylebenzle suggests) that are dynamic and create a similar structure as it evolves.

[0] https://en.wikipedia.org/wiki/Tesla_valve

evoke4908• 2 years ago

It is a hotel revolving door for sound waves.

But the door is also a sound wave.

cherryteastain2• 2 years ago

We already knew a way - a shockwave

jeezfrk• 2 years ago

A shockwave does not travel linearly.

cherryteastain2• 2 years ago

It does?

https://en.m.wikipedia.org/wiki/Shock_tube#/media/File%3ASho...

bckr• 2 years ago

This is different mechanism from the sound laser or SASER. The sound laser works like a laser, with a cavity where particles are bounced back and forth to stimulate a highly coherent beam of waves.

I’m not sure if this new mechanism is definitely better than the existing sound laser?

coding123• 2 years ago

I just want a way to not hear my neighbor's 10 yo bounce a basketball for 3 hours a day

BatFastard• 2 years ago

Have to wait for them to discover girls, or boys...

pizzafeelsright2• 2 years ago

Classical music while you're outside

Jerrrrrrry2• 2 years ago

Newly re-invented, quiet, airless 3D printed Basketballs, if you were so fiscally inclined.

satya71• 2 years ago

This seems to be similar to a microwave circulator. https://en.wikipedia.org/wiki/Circulator

gitaarik• 2 years ago

So could this be used at festivals and stuff to direct the sound only to the audience?

defrost• 2 years ago

see: https://news.ycombinator.com/item?id=41816544

Jerrrrrrry2• 2 years ago

I was curious as cousin commenters, and this helped make sense of things (and connect a few completely unrelated intuitions)

  As long as the effects of viscosity and diffusion are negligible, the fluid in a moving vortex is carried along with it. In particular, the fluid in the core (and matter trapped by it) tends to remain in the core as the vortex moves about. This is a consequence of Helmholtz's second theorem. Thus vortices (unlike surface waves and pressure waves) can transport mass, energy and momentum over considerable distances compared to their size, with surprisingly little dispersion. This effect is demonstrated by smoke rings and exploited in vortex ring toys and guns.

https://en.wikipedia.org/wiki/Vortex#Evolution

musicale• 2 years ago

I've met people who can do that.

Scientists found a way to make sound travel in only one direction

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