Another topic that Marcus and I have discussed deals with the evolution of standards of measurement. If I understand Marcus correctly, he is unhappy about the meter being defined in terms of the property of light and the definition of the second. Correct me if I'm wrong here, Marcus.
This, to me, is not a trivial point. There is good metrological reasoning behind this redefinition of the meter. The point is somewhat subtle, though, and if it confuses people on this list then it must confuse the person on the street even more. Actually, that last point assumes that the person on the street is familiar with the definition, which is very unlikely. What is more likely to be bandied about is the thought that the meter is not a constant quantity through the process of these definitions. Thus the myth arises that the meter is changing size. In fact, the yard (and therefore the foot and inch) changed size for Americans and for Brits in 1959, but the meter has not changed size since its original definition, except in the retrospective sense that newer and more precise methods of measurement today can determine the size of errors in previous methods. What has changed is the way in which the definition of the meter has been expressed these last two centuries as different methods of representing that standard have come and gone, being replaced in turn by methods of greater precision. Since most people have no background in statistics or in understanding measurement error, that point is lost on them. There is a similar conundrum with respect to the definition of the zero and 100 degree points on the Celsius temperature scale, but I would like to hold off on that for a bit. In the meantime, I'll stop here in discussing the meter to see if I have correctly represented Marcus's point and to see if there is interest in this topic. If there is no interest, then I'll end this thread here. Jim -- Metric Methods(SM) "Don't be late to metricate!" James R. Frysinger, CAMS http://www.metricmethods.com/ 10 Captiva Row e-mail: [EMAIL PROTECTED] Charleston, SC 29407 phone/FAX: 843.225.6789
