Does Wave Motion Challenge the Energy-Matter Relationship?

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SUMMARY

This discussion centers on the concept of wave motion as a mechanism for energy transfer without the transfer of matter, challenging traditional views on the energy-matter relationship. Participants clarify that mechanical waves, such as sound, transfer energy through a medium while the medium itself remains stationary. The conversation also touches on electromagnetic waves, which propagate through oscillations in electric and magnetic fields without a physical medium. The famous equation E=mc² is referenced, with participants debating whether energy transfer necessitates mass transfer, concluding that energy can be transferred without mass, as exemplified by laser beams.

PREREQUISITES
  • Understanding of wave motion principles
  • Familiarity with mechanical and electromagnetic waves
  • Basic knowledge of the equation E=mc²
  • Concept of energy transfer in physical systems
NEXT STEPS
  • Research the properties of mechanical waves and their mediums
  • Explore the nature of electromagnetic waves and their propagation
  • Study the implications of E=mc² in nuclear reactions
  • Investigate the concept of massless particles, specifically photons
USEFUL FOR

Students of physics, educators, and anyone interested in the fundamental principles of energy transfer and wave motion.

3trQN
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Wave motion is a means of energy transferrence without there being any transfer of matter...

Thats a quote from one of my physics texts, but it seems to me to contradict what I've been tought about enrergy and matter thus far, which isn't much i must add.

If wave motion can be defined as energy transfer without matter transfer, then doesn't that violate the famous equation?

If so, how would you define a wave?
 
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I think what they are trying to say is this: A mechanical wave transfers energy through a medium, but the medium itself does not get transferred from one point to another. Like sound energy travels through the air, but the air itself doesn't travel. (It just vibrates back and forth.) Or a ripple of a water wave traveling outward without the water itself moving outward.

(Don't worry about relativistic effects, if that's what you are thinking.)
 
How is energy transferred in a wave?

I understand the role of a medium for a mechanical wave, and that there is an absence of a medium for an electromagnetic wave moving through free space, or more to the point, the medium is ( though not a true medium ) the oscillations in the elctronic and magnetic fields.

I apreciate your reply, but i am worrying about relativistic effects :) maybe you can help clear my confusion a little.

Another thing that bothers me, is, hypothetically speaking, assuming the parallel postulate to be flase, what effect would such a condition have on the EM wave model?

thx :)
 
3trQN said:
If wave motion can be defined as energy transfer without matter transfer, then doesn't that violate the famous equation?
What equation?

Consider a microphone: sound waves cause it to vibrate, generating electricity, yet the air isn't moving from one place to another.

Consider an electric guitar - the guitar string doesn't move away from the guitar, yet it generates electricity in the pickup.

Consider an old-style reciprocating steam engine: the piston moves back and forth (net displacement: zero), yet it produces energy by spinning a shaft.
 
E=mc^2 was the equation i was referring to.

If you transfer energy, then don't you also transfer some mass?
 
Yes, actually, you do. It's the reason the components of a nuclear bomb have less mass after the bomb goes off than before it goes off.
 
really?

i don't think you need to transfer mass. for example, fire a laser beam. you transfer energy but no mass (considering photons to be massless).
 

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