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.
 A: Assuming a loose definition of the word "sound," the answer is yes.  
Let's consider the experiment you proposed.  Suppose you place two large diaphragms facing each other in space.  They could be simply large sheets of plastic stretched around a metal rim, like a drum head.  And "large" in this context means much larger than the average distance between particles.  Initially you would expect both diaphragms to be stationary and flat, since the same number of particles would impact both sides of both diaphragms, and the forces imparted would cancel each other out.
Now suppose you move one of the diaphragms toward the other a couple of feet.  That will send more particles heading in the general direction of the second diaphragm than would otherwise be the case.  A short time later, some of those particles, or other particles that were struck by those first particles, will impact the second diaphragm, causing a tiny increase in the number of impacts per second compared to the steady-state case.  With instrumentation that is sensitive enough, you could detect that change.  So it is fair to say that the "sound" has traveled through space.
