On Sun, 16 Mar 2003 00:41:13 Carl Sorenson wrote: >Mg vs. metric ton: >I'm with Gene and Gustaf in preferring metric tons to Mg.
My dear friend, Carl, I guess everyone would be entitled to have his/her preferences concerning certain units. However, one must ask the fundamental question: what's the SI unit that we should use to depict measured values of the order of magnitude of thousands of kilograms? Perhaps, to be politically correct, one would want to stick to 'thousands of kilograms'!!... However, if we have prefixes why should we and not use a one that would be suitable like the M? More on this below. > Jim Elwell, in >answer to your question, Mg is ridiculous because 1) a person will probably >be able to visualize 1000 kg much better than 1000000 g, ?? I'm sorry to say this, but there seems to be a flaw in your rationale, Carl. The 'visualization' aspect of measured values should be entirely independent of the prefixed unit being used. What I mean is that 1000 kg and 1 000 000 g depict the *exact same quantity*!!! The correct usage of SI prefixed units should be done in such a way that ideally an individual could form a mental picture of a quantity in ANY shape or form. In other words, when people hear something is 80 cL or 800 mL he should be able to mentally associate the correct "amount" related to those two different "units". Evidently it stands to reason that it's far easier for our brain to "count" less amounts, than large amounts, granted. In the case of the Mg if we train our brain to "recognize" such "increment" it should be easier for us to see a certain quantity and estimate its value if we used the Mg than if we used the kg, or the g. The same goes for the Mm, for instance. Now, whatever prefix we prefer we should be able to use it effectively to understand values being reported. > 2) the metric ton >is authorized for use, True, but the more important question would be, is it SI? Shouldn't we stick with preferred uses of SI "units"? > 3) normally people will have an idea what a metric >ton is (an analog to the short ton), ? But the 'metric ton' is **precisely the SAME quantity as 1 Mg**!!! Just like a liter is precisely the same as 1 cubic decimeter. But sometimes it may be ok for us to use "nicknames" for these things. So, I might be willing to *tolerate* 'metric ton' on such grounds, but Ideally I'd prefer for us to eventually move to use Mg (at least until BIPM addresses the issue of the kilogram name more definitively in the future!), since it appears that Mg would be the more correct prefixed unit for this order of magnitude. > 4) normally people will think that Mg >is the same thing as mg, having never seen the first but having seen the >second many times. I respectfully disagree, Carl, there clearly is a MAJOR distinction between a mg and a Mg, one is a billion times smaller than the other. There should be no chance for confusion here. > Comprehension will be served by using the metric ton as >a unit. Comprehension will be terrible in the vast majority of circles in >the U.S. if people use Mg as a unit (or Mm, etc.)... Yes, this one, granted. But, again, wouldn't we ideally want the US public to be more and more exposed to SI terms? Cordially, Marcus ____________________________________________________________ Get 25MB of email storage with Lycos Mail Plus! Sign up today -- http://www.mail.lycos.com/brandPage.shtml?pageId=plus
