>I agree that Tom's suggested reasons for having additional prefixes >close to the base value (his a and b above) are valid arguments to do >it, but I do not believe that is the reason it was done. I believe the >original metric system was intended to have a new prefix for every >additional power of ten (both positive and negative powers). But it >quickly became too cumbersome so they began using just the powers that >were multiples of 3. That worked fine, but the other prefixes were >never dropped.
In which case the current system was reached through evolution rather than careful design (and we know from the natural world, evolution tends to produce results that misleads people into thinking that there must have been an intelligent design behind it :-)). > ...but I think the same >argument can be used to claim that the prefixes deci, centi, deka and >hecto also are too many prefixes, thus making the system more >complicated than necessary by giving us too many prefixes to remember. But if this were true, then those prefixes would have withered away under evolutionary pressures as well. The fact that they didn't suggests that they *are* useful, in particular they are worth the complexity of the additional units. I would like to see greater use of these prefixes. For example decimeters seems particularly suitable for pool depths. >So I don't think it is good design. If it is good at all, it was just >dumb luck (a historical accident). Either way, whether it was careful design or evolution, the intermediate prefixes between kilo- and milli- have proved themselves useful. Let's not forget that one of the few positives features of Imperial/Colonial is that they have units that are suited to specific ranges (inches for measuring small distances, miles for big distance). SI achieves the same effect using prefixes, without the attendant conversion problems. Advocating anything that will make SI compare less favorably with Imperial/Colonial is not in our interest as promoters of the Metric System. ------------------------------------------------------------------- Tom Wade | EMail: tee dot wade at eurokom dot ie EuroKom | X400: g=tom;s=wade;o=eurokom;p=eurokom; Unit A2 | a=eirmail400;c=ie Nutgrove Office Park | Tel: +353 (1) 296-9696 Rathfarnham | Fax: +353 (1) 296-9697 Dublin 14 | Disclaimer: This is not a disclaimer Ireland | Tip: "Friends don't let friends do Unix !"
