--- Bill Potts <[EMAIL PROTECTED]> wrote: > Your km/ks (a deprecated form) and meters per second > (m/s) are, of course, > the same thing. > True, evidently, but the problem unfortunately is that 'ks' has absolutely NO relevancy in our time tracking system. Why? Simply because NO watch/clock in existence allow us to keep track of that!!! > Minutes and hours, although not purely SI > themselves, are accepted for use > with SI. > So it seems indeed. How much better though it would be if things were different in this regard, wouldn't they?... ;-)
> For scientific purposes, of course, speed is indeed > expressed in m/s. That's the very thing I sometimes cringe at! Why do we have to continue to resort to things like the above as 'for scientific purposes'? This gives us all the wrong impression that SI is for "nerds" (meaning people of science) and NOT for "the rest of us". I know this is a big misconception, but until we bring the SI to the *people's level* this is the kind of annoying situation we'll continue to experience for generations to come! When it comes to *time* related practical situations this won't change for the foreseeable future regrettably. So, the REAL problem though is that when it comes to the time construct, let's face it, the SI system simply failed MISERABLY in providing us with ANYTHING useful! And the real culprit is our inactive putting up with the mediocrities of 60-60-24 for BOTH time and angle systems (without the 24, of course)! NO, I'm not rekindling this discussion again, but simply jumping on some of our dear colleagues' comments here to drive the point home (or give food for thought) that there is more to "metrication" than just promoting "the status quo" IMHO. True, ok, when it comes to discussing this this is not the forum, so, again, I'll refrain from doing so. More and more though I'm convinced this "other" cause is worthy of our (ok, my...) pursuit. > However, as longer journeys (as opposed to trips to > the store) may take > several hours, expressing speed in km/h makes sense. Of course it does! And what does SI offer us to address that? NOTHING, NADA, ZILCH! So we're stuck with using minutes and hours as 'acceptable to be used with SI' because, again, SI simply does NOT have ANYTHING in its place to offer to the common folk! > If you have 240 km to > go and the limit is 120 km/h, you know it's going to > take 2 hours (assuming > no delays). If you have 255 km to go, you know it's > going to take a little > over 2 hours (7.5 minutes over if you're good at > mental arithmetic and want > to be really picky). > And how the above exercise would have been easier and more convenient if one could express time in ips... ;-) 30 m/i = 30 km/ki! End of story! ;-) :-) And below: > If 120 km/h is expressed in m/s, it comes to about > 35 m/s. If you were 240 > km from your destination and the limit was posted as > 35 m/s, would you be > able to easily estimate your travel time? Would most > people? > 'course not, Bill is absolutely right. But if we had ~30 km/ki as posted speed, we wouldn't need to worry about "converting" that to m/s (or vice-versa)... And if you were, like Bill said, 240 km from the destination, we would find that we were 8 ki (8% of a day!) away from it! But oh... forgot... we don't have watches in ki... ;-) > Common sense is important to the successful > implementation (and popular > acceptance) of SI. > AGREED! And that's why we'll continue to have to put up with minutes, hours, etc... Fine by some (or most), of course, but... (well.. you know the rest...). Thanks, Bill, for keeping us reminding of "work still left to do"... ;-) Cheers, Marcus > Bill Potts, CMS > Roseville, CA > http://metric1.org [SI Navigator] > > > >-----Original Message----- > >From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] > >Behalf Of John Hynes > >Sent: Monday, December 06, 2004 22:19 > >To: U.S. Metric Association > >Subject: [USMA:31596] RE: Some decimal time... jabs > > > > > >So, why do metric road signs say, "Speed Limit 100 > km/h"? Is this metric, > >or not? Why are not speeds expressed in seconds, > or kiloseconds? The same > >speed could be written (approximately) as 28 km/ks. > If we are going to > >promote the metric system, i.e. SI, and the hour is > not part of SI, then > >shouldn't speed limits be defined in meters per > second or some such? > > > >In fact, it seems that just about anywhere SI is > used, whenever times are > >expressed, such as for radioisotope half-lives, > instead of kiloseconds, > >megaseconds, gigaseconds, etc., minutes, hours, > days, years, etc., > >are used. > > > >What's the difference between using hours and using > miles or pounds? > > > >John Hynes > > > > --- Bill Hooper wrote: > >> The problem seems to be decimalization of the way > we measure time of > >> day (in minutes and hours). Change the minutes > and hours if you wish > >> (they are not part of SI anyway), but leave the > second (and the metre) > >> alone. > > > > ______________________________________________________________________ Post your free ad now! http://personals.yahoo.ca
