<blockquote><font class="small">In reply to:</font><hr /><p>I was told by someone that there is no sound in space is this true?<p><hr /></p></p></blockquote><br /><br />There is sound in space, but it's not the kind you're used to.<br /><br />Technically speaking, any pressure wave is sound, and there are definitely pressure waves in space. However, many of these pressure waves have wavelengths miles or even light years in legnth. Your eardrum can only vibrate a few millimeters, so it's not going to pick that up. <img src="/images/icons/wink.gif" /><br /><br />For everyday practical purposes, there is no sound in space; the medium of space is far too rarified (the opposite of dense) to transmit sound. However, for scientific purposes there is sound in space, and researchers do a lot of work observing the propagation of pressure waves through the interstellar medium. <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em> -- The Tenth Doctor, "Blink"</font></p> </div>