<p>This is a question regarding sound waves and space.</p>

<p>I know that sound waves must travel through a medium "air", enter our brains, and then we can decipher what exactly the sound is.</p>

<p>But in space, there is no air, and so does that mean that <strong>no sound waves are being produced</strong>, or that <strong>there are waves, but we cannot hear them because they never reach us</strong></p>

<p>And how can we tell? We cannot "hear" space, so who says its because theres no air, rather then just because "its not being produced in the first place?"</p>

CC BY-SA 3.0
2017-09-11T07:43:20.277Z
If there is no medium, there are no sound waves. In space there _is_ a medium (the interstellar and intergalactic medium) which may mediate sound waves, but because it's so dilute, the waves have extremely long wavelengths (like, lightyears). The [baryon acoustic oscillations](https://en.wikipedia.org/wiki/Baryon_acoustic_oscillations) is a great example. I started writing an answer, but you may bbe satisfied with [this physics.SE answer](https://physics.stackexchange.com/a/162210/70207).
pela
CC BY-SA 3.0
2017-09-11T08:10:57.800Z
Baryon acoustic oscillations is a signature of the acoustic oscillation in early universe, when the universe was so dense that there were acoustic waves (sound). Now it is too dilute so you don't have any, you just see its signature when you observe the disposition of galaxies in the universe.
Richard
CC BY-SA 3.0
2017-09-11T14:12:52.430Z
Very low density, so very low frequencies only: http://gizmodo.com/there-actually-is-sound-in-outer-space-1738420340
Wayfaring Stranger
<space><planetary-atmosphere><wavelength><vacuum>
Does space not make sound, or can we just not hear it?
K Split X
# Does space not make sound, or can we just not hear it?

(Asked by: username_0 on 2017-09-11)

This is a question regarding sound waves and space.

I know that sound waves must travel through a medium "air", enter our brains, and then we can decipher what exactly the sound is.

But in space, there is no air, and so does that mean that **no sound waves are being produced**, or that **there are waves, but we cannot hear them because they never reach us**

And how can we tell? We cannot "hear" space, so who says its because theres no air, rather then just because "its not being produced in the first place?"

**Tags:** space, planetary-atmosphere, wavelength, vacuum

> **Comments:**
> **username_1**: If there is no medium, there are no sound waves. In space there _is_ a medium (the interstellar and intergalactic medium) which may mediate sound waves, but because it's so dilute, the waves have extremely long wavelengths (like, lightyears). The [baryon acoustic oscillations](https://en.wikipedia.org/wiki/Baryon_acoustic_oscillations) is a great example. I started writing an answer, but you may bbe satisfied with [this physics.SE answer](https://physics.stackexchange.com/a/162210/70207).  
> **username_2**: Baryon acoustic oscillations is a signature of the acoustic oscillation in early universe, when the universe was so dense that there were acoustic waves (sound). Now it is too dilute so you don't have any, you just see its signature when you observe the disposition of galaxies in the universe.  
> **username_3**: Very low density, so very low frequencies only: http://gizmodo.com/there-actually-is-sound-in-outer-space-1738420340  

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