Rainer Thelonius Balthasar Straschill wrote: > If I remember my (very) basic university classes in physics, we usually > would test any theories we might have by bringing them to extreme values > and see what happens. If lower density = lower speed of sound, then we > would have sound travelling at infinite speed in vacuum. I don't believe > this is the case. In space there is no medium for sound to travel through. See the tag line to the film "Alien."