> Wasn't that long rod demonstration on a piano soundboard supposed to prove > that those > compression waves didn't care how far they traveled and it worked anyway? > As you said, the laws of acoustics work the same everywhere. Thought I would just comment on this sentence if I might. That demonstration went to prove that compression waves can and do indeed drive a sound board. Where one might draw from that proof or the relevant examples given that the significant factor in that proof had anything to do with distances I don't know. The effect of distances as per JD's comments about the violin bridge requires a completely different discussion then simple proofs of basic functions. Let me illustrate. Conceptually, its not all that hard to follow if one is willing to think along other lines for a moment instead of insisting on looking always in the same direction. Pond example again. This time 2D for simplicity. Given : Round pond and a rock dropped in the middle. Examine the developing wave patterns Then: Given: Round pond with two rectangular blocks protruding over the surface at say 2 and 5 o'clock, same rock dropped. Examine the developing wave patterns, especially those moving past the "interference". Now you can ask yourself what the difference in wave patterns mean. And you can ask yourself some other questions about what you are observing and that should get you looking at the whole thing from several perspectives... as it is a 3D thing really. Then think for a moment about your violin bridge with its cutouts and accept for a moment that maybe.... just maybe... all of this about compression waves deserves a bit more serious contemplation after all. -- Richard Brekne RPT, N.P.T.F. Bergen, Norway mailto:rbrekne@broadpark.no
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