On Wed, 18 Feb 2004 22:45:29 Bill Hooper wrote: >... >Because the SI official documents (you really should read them!) state >that hours and minutes are not SI units (because they are not coherent >with the rest of SI).
Indeed, agreed! However, the fact that these units in table 6 are *permitted* poses a serious question. Why should they??? The obvious answer is that there IS a gap (hiatus) in the SI framework that cannot be reasonably covered by the second alone (otherwise why would anyone *need* to make use of such units after all???). More below. ... >Section 4 of that document is titled "Units outside the SI". In the >introductory paragraphs (page 104) to that section is the statement: >"The inclusion of tables of non-SI units in this text does not imply >that the use of non-SI units is to be encouraged. With a few exceptions >discussed below, SI units are always to be preferred (to) non-SI units." > The above statement is quite ironic and even anecdotal! I mean, ok, 'not to be encouraged', yet the problem is that the SI has NOTHING to offer that would replace the need to use any of these!!! (I'm referring to minutes and hours, evidently) >On page 106 is a Table 6 titled "Non-SI units accepted for use with the >International System". Among others, this table includes: >the minute (60 s), >the hour (3600 s) and >the day (86 400 s). > However, there is one wrinkle that unfortunately shall *always* remain, actually two!... Day and year. But it's interesting to notice though that these are *nature* dependent, things totally beyond human's control. As someone already mentioned here in the past it's *impossible* to deal with these within ANY scientific framework. Therefore, we should stay out of it! But on those things that we *can*, we must, you see?! Theoretically we have no rasonable excuse NOT to! >... There are even several other tables of non-SI units >given, but only the ones in table 6 are permitted without condition. > True, but should anyone be surprised about that? Of course, it's 'without condition', why else since the SI has NOTHING to offer in their place, again I repeat? >Therefore, hours are not SI units (neither are minutes or days) but are >(perhaps reluctantly) allowed for use with SI. That use is acceptable >but does not make them part of the SI system. > Again, funny about the 'reluctantly', since they recognize "in-between-the-lines" that "Houston, there is a problem"! In order to satisfy these needs one would need to resort to something *outside* of the SI??? Fine, days and years, there is no choice because we're before a theoretical impossibility to deal with these, but the rest? What excuse can we offer? We've been dodging this issue for far too long, we should at least have the academic decency to recognize we don't wanna mess with these because we're afraid of the consequences of doing so or (worse) using the same excuses ifpists use NOT to metricate in the first place!!! (I don't mean to make these comments to be critical of our good colleague, Bill, here. He's got nothing to do with this issue!) Finally, below: >PS Some other units that you may be surprised to learn are NOT units of >the SI system are: >the litre Nickname for dm^3, no big deal. >the tonne (metric ton) Nickname for Mg, no big deal. >the hectare Nickname for hm^2, no big deal. >the bar (and, by inference, the millibar) Here we have a problem because SI does not offer more prefixes when I think it should (I.e. I'd welcome the creation of a battery of 4 additional prefixes to deal with the shortcomings associated with physical entities that delve into the high powers realm (2, 3). Had we created, for instance, the typo (10 to -4) and quintal (10 to +5), for instance, and this would have been dealt with) >the calorie and Calorie is no more, deprecated, should be scrapped outright! >the micron. Nickname for micrometer, no big deal. Marcus ____________________________________________________________ Get 25MB of email storage with Lycos Mail Plus! Sign up today -- http://www.mail.lycos.com/brandPage.shtml?pageId=plus
