Reply to several posts here. At 08:59 PM 21 June 2002 -0400, Joseph B. Reid wrote: >I support Jim. I distinguish three levels of importance: >1) Get the numbers right. >2) Get the symbols right. >3) All the other rules such as a space between the number and its symbol; >space instead of comma between triads of numbers; symbol but not name of >unit after the number; a sentence must not begin with a number; the unit >name must follow a number written out in letters; etc.
This is a much cleaner presentation of what I'm trying to say. I have no problem even putting out "recommended practices" for #3, but they should not become some holy grail, and we need to expect some diversity between fields of endeavor, languages, countries, etc. for #3. At 10:37 PM 21 June 2002 -0400, James R. Frysinger wrote: >...The SI depends extensively on what is called the quantity calculus ... it >boils down to viewing quantities as products of numbers and units and to >applying the rules of first year algebra to both parts. We certainly agree here. I want to make the point, however, that other than scientists and engineers, not only do people NOT understand "quantity calculus," they have very, very little need for it. In other words, 95% of the adult population of the world rarely if ever does any sort of "dimensional analysis" (as we called it when I was in school). >...My guess is that all of the above led to the development of an >intentionally lean standard... Some might see its few rules as stifling, >claiming that their even simpler version causes no confusion. An example >of this might be the proposed omission of the unit after all but the last >product of numbers. Indeed, in that one field or even in several fields >there might be no possibility of confusion arising. But the SI is there to >cover all fields of measurement ... To allow some fields to simplify rules >of their choosing while others must adhere to those rules for the sake of >safety and clarity would be to make the SI no longer universal. Several comments: (1) correct me if I'm wrong, but neither the BIPM standard nor IEEE/ASTM SI 10-1997 address the example we've been using (1 mm x 2 mm x 3 mm, vs. 1 x 2 x 3 mm). They DO, however, address putting a space between a number and its symbol, which I think is even less necessary for clarity. (2) For our example, some confusion may be due to technical people making something out of that which is not technical, illustrated by your statement "... omission of the unit after all but the last product of numbers." When we create a part description for a shipping box, and name it "box, shpng, 100x200x300mm" you see it as a "product of numbers." Non-technical people see it as three linear dimensions, and in no way related to being a product or volume. Perhaps we would all be more comfortable with: 100-200-300mm, or 100w200d300hmm, or 100/200/300mm or some different form that ensures no confusion with true products or volumes. (3) Regardless of what you think of my examples above, I can say this: those of us in commerce have practical limitations that REQUIRE brevity in such things. As people knowledgeable about proper metric, us USMA types can either provide means for brevity, or people will develop them ad-hoc. I would welcome suggestions that address the brevity issue while keeping metric purists happy. And, no, mm^3 does not qualify: it is not understood by most people and writing a superscript 3 is nearly impossible in most accounting systems. >As for being branded a heretic, you are safe. No subpoena will be >thrust into your hand demanding your appearance before a tribunal in >Sevres, there to be caned with a meter stick. Thanks, I'll sleep better tonight. >You merely risk >demonstrating a departure from the rules that might be innocuous in your >field but perhaps harmful in others. And, of course, you are subject to >the pleasure and wrath of legally governing bodies who invoke those >rules and may show varying degrees of tolerance. Actually, I am subject to no such thing. Since my company does not sell consumer products, as far as I know there is no "legally governing body" in the US that has any authority over how we use measurements in our business, except if fraud is involved (e.g., calling a pound a kilogram). I can even invent new units of measure if I wanted to -- perhaps a "nat" (as opposed to the common unit "nit") and call my displays "300 nat" displays when I really have not even defined "nat." Of course, I would soon be out of business, thanks to the delightful forces of capitalism that punish such foolishness. >... The SI publishes a >very sparse set of units, prefixes, and rules for the sake of avoiding >that. That's the simple kind of approach I prefer. If I point out that >something a person writes doesn't comply with the SI, that doesn't mean >that I consider the author a heretic but merely one who didn't comply >with the standards specified in the SI. After all, it ain't that hard to >comply with the "grammar rules" of the SI. We're pretty much in agreement, except for (what started all this) some practical issues. I even agree that, with a few exceptions, it is easy to comply, and continue to wonder why I see so much "non compliance" in products from metric countries. At 01:06 AM 22 June 2002 -0400, kilopascal wrote: >The people who run the media are part of the masses. They may not be >stupid, but they are ignorant and I'd bet non-caring of correct mathematical >and metric practices. And thus their errors are passed onto the masses who >follow the media. A never ending circle. > >The media should be made to realise that proper use of SI and its notations >are just as important as spelling and grammar. For once we are somewhat in agreement, John. I agree with the "ignorant" part, but less so with the "non-caring" part. Like all fields, the media is very tradition-bound, and (particularly in the print media) most publications have style books that they follow rigorously. Our job is to get copies of these books (they generally will sell them), then point out where their style differs from international standards. I've done this with two publications (US News & Word Report and PC Magazine). USN&WR is actually quite good, and references the "Metric Style Guide for the News Media," published by NIST. If we could get all the media to follow this guide, correct usage would improve dramatically. PC Magazine has not even acknowledged the several letters I have sent them. Jim Elwell, CAMS
