Can photons act as medium for sound?

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SUMMARY

Photons cannot act as a medium for sound wave propagation due to their inability to collide with each other frequently enough to transmit sound. While a powerful, modulated light beam can create temperature variations in a gas, resulting in audible pulses, there is no known system that directly transmits audio signals using photons without an intermediate transducer. The discussion highlights that sound waves require a medium, such as air, and that phenomena like thunder are shockwaves from rapidly heated air, not sound transmitted through light.

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  • Understanding of photon behavior and interactions
  • Knowledge of sound wave propagation in gases
  • Familiarity with modulation techniques in optics
  • Basic principles of thermodynamics related to gas expansion
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aditya_the quazarboy
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can light collectively or individual photons act as a medium for propagation of sound waves?
 
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No. For one thing, photons do not collide with each other.
 
aditya_the quazarboy said:
can light collectively or individual photons act as a medium for propagation of sound waves?
It's not clear what the context of this question is. It is certainly possible to use a powerful, modulated light beam to vary the temperature in a gas at a high rate, which could manifest itself as an audible pulse as the gas expands. But i don't know of a system that actually uses the effect to 'transmit' an audio signal and directly produce sound without some intermediate form of transducer.
 
Ever listened to a radio?
 
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dukwon said:
Ever listened to a radio?
I don't think that radio waves change the temperature t transmit sound
 
dukwon said:
Ever listened to a radio?

no! that is not correct ... not in the context of the OP's question
 
lychette said:
I don't think that radio waves change the temperature t transmit sound
If you focus a powerful case beam onto a small volume, it will raise the temperature fast and that can be audible. It is very hard to produce heating of air with focussed radio waves as the losses are too low to provide enough energy.
 
What about lightning.
 
  • #10
Buckleymanor said:
What about lightning.
That would be electrical heating - not optical.
 
  • #11
Buckleymanor said:
What about lightning.
The lightning isn't carrying any information that represents a sound.
The thunder is a shockwave resulting from rapidly heated air, and is a mix of random frequencies.
 
Last edited:
  • #12
mfb said:
Not frequent enough to transmit sound, but sometimes they do collide.

I am not sure this works, even in theory. Gas molecules trying to occupy the same space collide every time. Photons passing near each other interact a fraction of the time proportional to E6. That means the most energetic photons tend to interact more, and thus lose energy. In such a dissiptaive medium, the solutions to your wave equation are not sine and cosine, but rather sinh and cosh. I don't think you get sound waves. Or even waves.
 
  • #13
If this discussion continues I'll split it out. It is interesting, but not (B) level.
Vanadium 50 said:
That means the most energetic photons tend to interact more, and thus lose energy.
There has to be some equilibrium, especially if we ignore processes that change the number of photons.
I don't know how a region of higher density would propagate if we have a photon gas much larger than the mean interaction length.
 
  • #14
Don't know if this is what the OP was asking, but in laser serveilance, a laser is bounced off the window of a room, and into a receiver. Any sound waves in the room will cause the laser to vibrate. These vibrations can be measured by the receiver, and converted into sound over a speaker. Of course, the vibrations in the beam are not sounds per se, but the laser could be described as "a medium" that carries the sound from the room to the receiver.
 
  • #15
Not quite what the OP meant but... some decades ago there was a project in one of the electronics magazines that used a modulated beam of light (pair of torches) to send voice between two houses. Think it was intended as a kids toy.
 

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