What Would Sound Like at the Speed of Light?

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Discussion Overview

The discussion revolves around the hypothetical scenario of a person traveling at the speed of light and the implications for sound perception. Participants explore concepts related to sound in different mediums, the effects of relative motion, and the nature of velocity as a relative quantity.

Discussion Character

  • Exploratory
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • Some participants propose that if a person were to travel at the speed of light, the perception of sound would depend on the medium they are in, with one suggesting it could be a "mad deafening roar" or complete silence.
  • Others argue that if traveling in a craft through air, the person would experience sound normally, but observers would hear the sound from any explosive event after a delay based on distance.
  • A participant notes that in the absence of matter, at speeds near light speed, the traveler would not notice anything unless looking out the window, emphasizing the importance of the reference frame.
  • Another participant mentions that everyone is currently moving at high speeds due to cosmic expansion, but this motion is not perceptible in their internal frame of reference.
  • Some participants clarify that the concept of velocity is relative, and one questions the meaning of "internal frame."

Areas of Agreement / Disagreement

Participants generally agree on the relativity of motion and the perception of sound depending on the medium and reference frame. However, there are competing views regarding the implications of traveling at light speed and the effects of cosmic expansion on individual perception.

Contextual Notes

Limitations include assumptions about the medium of travel, the definition of reference frames, and the unresolved nature of sound perception at relativistic speeds.

NiceJerkGuy
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If man were able to travel the speed of light - what would it sound like to this man? Would it be a mad deafening roar? Or would it be complete silence? What does the speed of light sound like?
 
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If he was traveling in a craft, sound for him would not change from the way it is in our everyday world. If we were watching him pass by, he would burn up from the friction in the sound medium (air). Then you would hear the sound from the blast about 1 second later for every mile distance from the explosion.
 
NiceJerkGuy said:
If man were able to travel the speed of light - what would it sound like to this man? Would it be a mad deafening roar? Or would it be complete silence? What does the speed of light sound like?

It he were traveling in space in the absense of matter then at speeds near light speed (you can't go at light speed) he wouldn't notice anything unless he was looking out the window. This is because its impossible to even speak of moving unless you've stated what your moving with respect to. Right now you are moving at near the speed of light with respect to some frames of reference.

If he were moving near c with respect to the average rest frame of matter in the universe (locally) then he'd notice nothing as welll unless he looked out the window. Then, because he's traveling at near the speed of light with respect to the cosmic background radiation (locaal zero momentum frame) then he'd see gamma rays in the direction of motion and super lw frequency rays when he looked out his rear window.

Pete
 
I'm traveling at almost the speed of light right now (as I imagine everyone on this forum likewise is doing). Note that such a statement in no way contradicts the perspective that I am also at rest.
 
exackly. all of us are traveling at imencelly high speeds right now (space expansion), but because we are in an internal frame, this has no effect on us and we cannot notice it.
 
It has nothing to do with space expansion. It is the issue that velocity is a relative quantity.

What's an "internal frame?"
 

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