Transverse Doppler effect of sound?

In summary, the discussion revolves around the existence and testing of the transverse Doppler effect for sound waves. The original poster is looking for a peer-reviewed article on this topic and asks why it hasn't been tested. The conversation then delves into the theory and intuition behind the transverse Doppler effect, with one participant providing a link to an online reference for the Doppler effect in both sound and light. The discussion concludes with the understanding that the transverse Doppler effect for sound will be too small to measure at speeds below the speed of sound.
  • #1
mrsmitten
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I have been trying to find an per reviewed article where it is actually tested that sound does not have a transverse Doppler effect. I figure that its probably do to my lack of resources. if it is could somebody give me a link to the article i would appreciate it. If not, i must ask why has it not been tested?
 
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  • #2
It is a rather trivial piece of mathematics to generalise the usual Doppler formula to a source/detector moving in an arbitrary direction. It is not very different from the usual derivation.

It is also very inuitive. If the frequency from a source moving towards you increases and from a source moving away from you decreases, you must somewhere get a zero effecr when you rotate the source velocity.
 
  • #3
I have never looked for such a thing. Since there is no theory that expects transverse Doppler for sound, as far as I am aware (the speed of sound being so low that relativistic effects will be utterly swamped by noise), I would be surprised to find any direct test. Without a theory predicting a transverse Doppler how would you know how precise your measurements would need to be to rule it in or out?

Theoretical considerations aside, given that Doppler sonar is a fairly well developed technology I suspect that any deviation from "no transverse Doppler" is pretty tightly constrained. I'd start by looking into Doppler sonar publications if I thought this was worth investigating.
 
  • #4
mrsmitten said:
I have been trying to find an per reviewed article where it is actually tested that sound does not have a transverse Doppler effect. I figure that its probably do to my lack of resources. if it is could somebody give me a link to the article i would appreciate it. If not, i must ask why has it not been tested?
This isn't peer reviewed, but it is my favorite online reference for the Doppler effect in both sound and light. It does a good job of showing how the same equations apply for both. You can use this to calculate the magnitude of the transverse Doppler effect for sound.

http://mathpages.com/rr/s2-04/2-04.htm
 
  • #5
Testing that something does not happen (at all) is tricky. You can always say that it is below your experimental sensitivity.
But the people using ultrasound Doppler to measure and visualize blood flow know very well that the effect becomes "zero" when the flow is perpendicular to the line of sight.
You can find papers if you look up "Transverse Doppler ultrasound".
In this one, for example:
http://www.jultrasoundmed.org/content/12/9/497.abstract
 
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  • #6
Orodruin said:
It is a rather trivial piece of mathematics to generalise the usual Doppler formula to a source/detector moving in an arbitrary direction. It is not very different from the usual derivation.

It is also very intuitive. If the frequency from a source moving towards you increases and from a source moving away from you decreases, you must somewhere get a zero effect when you rotate the source velocity.

As intuitive and trivial as it may be i would feel much more comfortable about educating people that the transverse doppler effect does not exist for sound if there were experimental proof, rather than relying on intuition.

Ibix said:
I have never looked for such a thing. Since there is no theory that expects transverse Doppler for sound, as far as I am aware (the speed of sound being so low that relativistic effects will be utterly swamped by noise), I would be surprised to find any direct test. Without a theory predicting a transverse Doppler how would you know how precise your measurements would need to be to rule it in or out?

I do not know. I probably wouldn't of ask the question if i did. I figure that your main concern is where did you get this question without having a supporting theory. I was wondering if the transverse Doppler effect was a property of all waves. When light was first classified as a wave it was because of its wavelike properties. To me then It would seem proper that if we see any effect that involves light to test it against a different wave type "like sound" to see if it produces the same effect, rather than relying on intuition or waiting for a theory.

Dale said:
This isn't peer reviewed, but it is my favorite online reference for the Doppler effect in both sound and light. It does a good job of showing how the same equations apply for both. You can use this to calculate the magnitude of the transverse Doppler effect for sound.

http://mathpages.com/rr/s2-04/2-04.htm

Thank you, that was very interesting i will need to read through it a couple more times though. if i understood it correctly i should be able to measure the transverse doppler effect of sound at speeds less than the speed of sound? But to calculate it I would have to set the value of c to the speed of sound.
 
  • #7
mrsmitten said:
Thank you, that was very interesting i will need to read through it a couple more times though. if i understood it correctly i should be able to measure the transverse doppler effect of sound at speeds less than the speed of sound? But to calculate it I would have to set the value of c to the speed of sound.
No, the value of c is 299792458 m/s. In this paper's notation you would set ##c_s## to the speed of sound, or about 340 m/s.
 
  • #8
Dale's link says what my parenthetical aside says - transverse Doppler comes from relativistic effects, so it will be unmeasurably small for anything moving below the speed of sound (which is about 0.000001c). If the source is moving above the speed of sound you won't have a well-defined Doppler effect to measure.

You need to set ##c_s## to the speed of sound and ##c## to the speed of light.
 
  • #9
Ibix said:
Dale's link says what my parenthetical aside says - transverse Doppler comes from relativistic effects, so it will be unmeasurably small for anything moving below the speed of sound (which is about 0.000001c).
Yes, exactly. And nasu also mentioned the same thing.
 
  • #10
Ibix said:
You need to set ##c_s## to the speed of sound and ##c## to the speed of light.

Ok, i knew i was missing something i was reading ##c## as ##c_s##

Thanks
 

FAQ: Transverse Doppler effect of sound?

1. What is the Transverse Doppler effect of sound?

The Transverse Doppler effect of sound is the change in frequency of a sound wave due to the relative motion between the source of the sound and the observer. It is similar to the well-known Doppler effect, but it occurs when the source and observer are moving perpendicular to each other.

2. How does the Transverse Doppler effect of sound occur?

The Transverse Doppler effect of sound occurs because the relative motion between the source and observer causes the sound waves to be compressed or stretched as they travel. This compression or stretching results in a change in frequency, which is heard as a change in pitch.

3. What factors affect the Transverse Doppler effect of sound?

The main factors that affect the Transverse Doppler effect of sound are the relative velocity between the source and observer, the frequency of the sound wave, and the angle between the direction of motion and the direction of the sound wave.

4. How is the Transverse Doppler effect of sound used in practical applications?

The Transverse Doppler effect of sound is used in a variety of practical applications, such as in measuring the speed of moving objects and in Doppler radar systems. It is also utilized in medical imaging techniques, such as ultrasound, to detect the movement of blood and tissues.

5. Can the Transverse Doppler effect of sound be observed in everyday life?

Yes, the Transverse Doppler effect of sound can be observed in everyday life. For example, when a car with a siren passes by, the pitch of the siren will appear to change as it moves past an observer. This is due to the Transverse Doppler effect of sound.

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