# can a really loud sound travel in space?

I heard in a discovery news video that there is one particle every cubic cm in space. So, if i were to vibrate a circular body of say mass $10^7$kg at $10^{22}$Khz, would i be able to hear a sound from say 1 metre away in space, assuming i will somehow live? Im asking this because there is no documentation anywhere that sound could ever travel in space. Im 14, so I don't know how many zeroes to include in the values. Thanks. If this is true, the big bang would have produced an extremely loud sound.

• Your circular body is called a "diaphragm." Its mass doesn't matter: what matters is its area. I know pretty close to zilch about the propagation of "sound" through the almost-vacuum of deep space, but I bet there is a relationship between the mean free path of the particles out there, their temperature, and the shortest wavelength/highest frequency that can propagate. I'm guessing that the highest frequency would be VERY low. Not cycles per second, but maybe more like cycles per year. – Solomon Slow Mar 26 '15 at 20:02
• Also, I'm guessing that in order to detect the sound, you would need a Huge diaphragm---like maybe you could hear it if your ear drum was the size of a planet. Or, I don't know. Maybe even that would not be big enough. – Solomon Slow Mar 26 '15 at 20:03
• I expect the big bang produced a loud sound anyway; the universe was a lot denser back then. – stanley dodds Mar 26 '15 at 20:03
• – BowlOfRed Mar 26 '15 at 20:27
• Sound waves in the early Universe: en.wikipedia.org/wiki/Baryon_acoustic_oscillations – Kyle Oman Mar 26 '15 at 21:22