Robin Hufford wrote: > The coherence or incoherence of motion is, really, central to this issue. On > one hand, the chaotic, random motion of the molecules and atoms of a substance is > at an extreme; that of incoherence. Of course, this is heat; vector analysis is > useless. On the other perfect translatory motion or fixed axis rotary motion of > a body is at the other exteme; that of coherence. In this case the molecules or > atoms are moving in parallel paths. In translation the vectors of all the > particles of a body have equal direction and magnitude; all the particles of the > body have the same acceleration. The motion of the body can be represented by > the center of mass. yes... obvious that the two camps are operating with different concepts of motion. > I attempted to suggest the importance of the distinctions of > motion a month ago, but the contrary camp has paid no attention to these details. This is pretty typical actually Robin, and it has frustrated me greatly earlier in discussions on the list. Now I first have to say that what you describe above is beyond me to be able to confirm or refute. But in a discussion such as this, if one side is to matter of factly that the other is wrong, then they simply have to confront deal with statements such as the one you make above, and in a fashion other then simply writing off the relevance without further ado. On the other hand, you need to be able to point at reference material as well, where the interested reader (such as myself) can turn to. Who (personally) is right and wrong is really of no consequence. What is important is that readers participants get stimulated to increase their knowledge by reading, and experimentation, and thoughtfull reflection. Yet again... I ask you and others... why should we be concerned to do so in this particular instance (aside from the occasional nutcase like myself who simply thrives on this kind of thing) What ramifications for design issues can either perspective have that are in conflict with the other ? If viewing soundboard functionality in the persepective that Del, Ron, and many others will yeild for all practical purposes the same or perhaps even better results then another perspective, is it important then to know which perspective most closely represents the real truth of the matter ? I would think not. On the other hand if there are significant ramifications and thus reason for making the distinction, then we should begin to hear what these might be eh ?? I've asked for this three or four times now and havent really gotten any response from either side. > > Rotation about a fixed axis is somewhat more complicated but, nevertheless, the > particles of the object move in parallel paths and the motion is highly coherent. > Where motion is incoherent vectors are not employed to measure the extent and > magnitude of this motion. The quantity of energy possessed by the body is used > instead. In the case of heat, as we all know, this is of course, indicated by > temperature and density. > Where motion is coherent, that is the motion of translation or rotation, or > combinations of the two, vector methods are useful, as we all know. > Those of the contrary view, disregard, in my opinion, the importance and > nature of wave motion and elastic action and confuse mightily the nature of > vibration which may occur both as recurrent translation or flexion if you will, > and wave motion. For example, coherent motion in the evidently moving tines of a > the vibrating tuning fork, to return to the chronically misunderstood analysis of > the last month, exists in one and the same body, that is the tuning fork, with > the demonstrably different motion of wave propagation in the base of the tines > and the stem. Even though such motions are evaluated on the particle level in > terms of force, mass and acceleration, on a larger scale they are best judged by > the energy they possess, as should be judged the transfer relations of the > string. Again... best for what ? In our application (designing an instrument) how is it better to adhere to the view you give visa vi the view presented by the other camp ? What are the differences that could result in choosing one over the other ? > With a kind of perplexity I must note that it seems the contrary > proponents have a peculiar characteristic of their view: Where they see motion > they claim it doesn't exist, where they don't see it they claim it does. Yes.. I have noticed that too... and its really got me scratching my head. But then I also wonder.... how did instrument makers of old produce such wonderful instruments without knowing jack diddly of these matters ? They probably had an even different paradigm. Those were the days of telelurgic currents and Knights of the Templar.... -- Richard Brekne RPT, N.P.T.F. Bergen, Norway mailto:rbrekne@broadpark.no http://home.broadpark.no/~rbrekne/ricmain.html
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