At 4:47 PM -0600 12/18/01, Ron Nossaman wrote: >It doesn't matter if it's possible or not. Regardless of whether the >strings are moving in the same or opposite directions, there will be cyclic >changes in string tension as the vibrating strings pass from their far >limit of excursion, through a relatively straight line neutral, to the >other far limit and back. The tension swings will necessarily pull the >bridge forward and back, You are asking the list and me to accept that a variation in tension of a few pounds at most due to the trasverse vibrations of two strings is sufficient to cause a rocking of a long bridge firmly glued to a soundboard and held in position at its top by over ten tons force? You'd have the bridge in smithereens before you could rock it with a crowbar let alone such a minute force. > and the bearing load changes will push it up and >down. The bridge will move, and the soundboard will follow. So you keep saying. > >I say that the sound emitted from the soundboard will be practically >>identical whether the two strings (according to your theories) are >>acting in concert to move the soundboard in one direction or whether >>they are counteracting each other and therefore quite unable to >>produce any movement. >> >>Answer me that. >> >>JD > >If the strings moving in opposition could be kept exactly out of phase, >that could very well be correct for the reasons I gave above. It will be correct with or without any of your impossible hypotheses. It happens all the time when a piano is played. The net force exerted by the strings that might tend to move the bridge in any direction is on average zero. This would mean that by the laws of probability there would frequently occur a zero force and, according to you, total silence. Very embarrassing for the sensitive pianist! JD
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