<!doctype html public "-//W3C//DTD W3 HTML//EN"> <html><head><style type="text/css"></style><title>Re: Sound Propagation</title></head><body> <div>At 5:22 PM +0100 1/9/02, Richard Brekne wrote:</div> <div><br></div> <blockquote type="cite" cite>Well, see the reason I ask is that your "radiate" seems to correspond pretty good with Olsons description of sound board radiation in which case I see almost the exact same description when it come to Benades description about the longitudinal nature of transverse like surface waves. In all this you could sort of look at these as a huge collection of tiny  ... Olson uses the word "pumps" pushing away at the air in his description of sound board radiation.... btw.. I read your stress waves reply to Phil and this also points in this same direction. You said then<br> <blockquote>"Acoustic radiation is caused by minute pressure differences at the surface of a body."</blockquote> </blockquote> <div><br></div> <div>Interesting that Olson should have used such a very similar analogy.  You've mentioned him before but given no details.  Who exactly are Olson and Benades or what are the books in question?</div> <div><br></div> <div>The analogy of his tiny pumps or my little pulsating fountains is, of course, an extreme simplification.  The final picture will be vastly more complicated.  What I hope we can eventually arrive at is a good basic understanding of the principles involved and the nature of the wave forms generated.  As I've recently said, I think it would be helpful in the early stages to consider the system as composed of one homogeneous isotropic solid body (which would, I guess, actually work after a fashion) and to avoid discussion of the behaviour of fluid bodies.</div> <div><br></div> <div>We have a lot of studying to do.</div> <div><br></div> <div>JD</div> <div><br></div> </body> </html>