MadSci Network: Astronomy |
Thank you for your question. While it is true that there are molecules in space, the distance between them is enormous. Sound is a pressure wave through a medium. We are most acquanted with audible sounds, transmitted through the air. Here on earth, there are billions times billions of molecules per cubic foot. But in space, its more like a few molecules per cubic foot. But one can still have a pressure wave form and propogate through that medium - but the intensity of that pressure wave is exceedingly small and the wavelengths exceedingly long, usually undetectable. But we have made observations of at least one "sound" in space. http://www.space.com/scienceastronomy/blackhole_note_030909.html The notes from this humming black hole are far below any audible tone, but it does represent a pressure wave in space. Now also please note, this black hole is in a region of space with higher than normal gas density than much of space. So to return to your question, you are correct in that sound can travel in space, but in general the density of the molecules in space are so very thin - one would need an exceedingly sensitive instrument to detect it. To borrow a line from a famous movie trailer, in space no one can hear you scream.
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