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Sound waves transport a small amount of mass, according to theory

physics.aps.org

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Re: Sound waves transport a small amount of mass, according to theory

#2

Post by novacole »

Do sound waves have mass or transport/displace matter? The article does seem clear on this to me. Not a physicist so I could be totally wrong here, but having mass is not necessarily the same as being matter, correct? Since matter is made of atoms, and sound is just waves. Maybe someone can help explain this to me.

Re: Sound waves transport a small amount of mass, according to theory

#4

Post by epicwhaleburger »

novacole wrote: post #2

Do sound waves have mass or transport/displace matter? The article does seem clear on this to me. Not a physicist so I could be totally wrong here, but having mass is not necessarily the same as being matter, correct? Since matter is made of atoms, and sound is just waves. Maybe someone can help explain this to me.

Electrical engineer here. Sounds waves are called transverse waves because their displacement moves in the positive/negative y directions, which appears to give the impression that the wave is a single traveling particle. Instead the sum of the displacement creates the "traveling wave", which is similar to a wave an audience might do at a sporting event. I don't think this article did a great job describing what they meant by mass. I believe they blow the word "Phonon" a bit out of proportion. High energy physics is an incredibly hard topics where very few people are smart enough to read such a paper with confidence so these are just my humble thoughts.

Re: Sound waves transport a small amount of mass, according to theory

#6

Post by whatshisface »

epicwhaleburger wrote: post #4
novacole wrote: post #2

Do sound waves have mass or transport/displace matter? The article does seem clear on this to me. Not a physicist so I could be totally wrong here, but having mass is not necessarily the same as being matter, correct? Since matter is made of atoms, and sound is just waves. Maybe someone can help explain this to me.

Electrical engineer here. Sounds waves are called transverse waves because their displacement moves in the positive/negative y directions, which appears to give the impression that the wave is a single traveling particle. Instead the sum of the displacement creates the "traveling wave", which is similar to a wave an audience might do at a sporting event. I don't think this article did a great job describing what they…

I think you might have got transverse swapped with longitudinal, transverse is perpendicular to the axis of propagation (string waves and EM waves), longitudinal is parallel (sound waves in fluid), and mechanical solids can support both (you can have a transverse sound wave in an iron bar but not in the air).

Re: Sound waves transport a small amount of mass, according to theory

#8

Post by mjfl »

If you have a nonlinear interaction of a wave with a media, you might have a quadratic term A^2 cos^2(wt). If you remember your trig identities, you'll remember that two sinusoidal functions multiplied together decomposes into the sum of signals at the sum and difference frequencies: cos(w_1 t)cos(w_2 t) = 1/2*(cos((w_1 + w_2)t) + cos((w_1 - w_2)t)).

In this case the sum wave is at twice the frequency of the original wave, and the difference wave has 0 frequency - it is just mass transport. I have a feeling that is what is going on here.

Re: Sound waves transport a small amount of mass, according to theory

#9

Post by tranchms »

I was on a plane today thinking about recent research that uses vibrational/waves to interact with objects. Researchers can suspend and manipulate objects with these waves.

I was thinking, why isn’t it possible to use this technology to create levitating objects or vehicles???

Like UFO type flight.

Just attach powerful emitters around the craft.

This article makes me think this might be possible.

F= m*a

If waves possess mass, then it could be used as a means of force.

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