Do physical (macroscopic) waves consist of matter?

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SUMMARY

This discussion clarifies that physical waves, such as sound, do not consist of matter being emitted from a source. Instead, sound is a mechanical wave that propagates through oscillations of air molecules, which remain mostly in place around an equilibrium position. The conversation highlights that sound waves are variations in air pressure and density, and introduces the concept of phonons, which are associated with mechanical vibrations but do not carry mass. Therefore, no matter is lost when sound is produced, debunking the myth that speaking emits physical matter.

PREREQUISITES
  • Understanding of wave mechanics, specifically sound waves
  • Familiarity with concepts of pressure and density in fluids
  • Knowledge of phonons and their role in sound propagation
  • Basic grasp of electromagnetic waves and their properties
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  • Research the properties of sound waves and their propagation in different media
  • Study the concept of phonons and their significance in material science
  • Explore the differences between mechanical waves and electromagnetic waves
  • Investigate the mathematical modeling of wave phenomena, including pressure and density variations
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Students and professionals in physics, acoustics engineers, and anyone interested in the fundamental principles of wave behavior and sound propagation.

Vitani1
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When I think of a wave propagating through space I think of a geometric wave-like structure propagating through the matter in the surrounding environment. If someone yells and you hear their voice is it actual matter that is emitted and that your ears pick up on? If this were the case there would be a lot of "clutter" in your ears from all the noise... what is the answer?

Thanks
 
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Try googling for "what is sound".
 
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Vitani1 said:
Summary:: ]

When I think of a wave propagating through space I think of a geometric wave-like structure propagating through the matter in the surrounding environment. If someone yells and you hear their voice is it actual matter that is emitted and that your ears pick up on? If this were the case there would be a lot of "clutter" in your ears from all the noise... what is the answer?

Thanks
Waves are oscillations of something. They may be the oscillation in position of air molecules in the longitudinal direction as sound propagates from the source to the receiver (the waves propagate, but the air molecules stay mostly in place), or they can be the transverse oscillation of water molecules as gravity waves propagate across the ocean or a lake. Or they can also be electromagnetic in nature, which does not require a medium at all.

You can start with the Wikipedia article: https://en.wikipedia.org/wiki/Wave

The particles (of water or air or string/rope molecules, etc.) that oscillate tend to oscillate around an equilibrium position. That is why the air molecules don't move from your mouth to the ear of your listener. When you speak, that "bangs" the air molecules outside your mouth together, and that bangs molecules together a little farther away from your mouth, and so on, all the way to the air molecules outside and inside the listener's ear canal.
 
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We all have heard about photons, which are totally massless 'particles' that are associated with electromagnetic waves. There are less well known particles that are called Phonons and they are associated with mechanical vibrations (sound) in materials. They travel but are not regarded as having mass; the air / water / metal doesn't go anywhere when sound travels through.
 
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You already have got good answers above, but I want to comment too:
Vitani1 said:
If someone yells and you hear their voice is it actual matter that is emitted and that your ears pick up on?
No matter is emitted that travels from source and outwards.
If that was the case we could lose weight (mass) by simply talking. :)
And loudspeakers would also lose mass over time if matter was emitted. :)
What is propagating is sound, and sound is differences in air pressure/density which can be modeled as waves.
 
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Thank you.
 
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