ISO and BIPM are careful to ensure that there is compatibility between their respective standards, even if there is not a 100% overlap - for example, ISO 31 used to define the yard, foot, inch etc, but these have now been deprecated.
-----Original Message----- From: owner-u...@colostate.edu [mailto:owner-u...@colostate.edu] On Behalf Of James R. Frysinger Sent: 02 April 2010 22:20 To: U.S. Metric Association Subject: [USMA:47023] Re: Correct me if I'm wrong... ISO favors "a", but I seem to recall they define that as 365.25 d exactly. CIPM, CCU, and other consultative committees (CCs) don't seem to have been swayed to see the need. Jim Martin Vlietstra wrote: > It is a pity that the BIPM could not reserve a symbol without a formal > definition for the year to ensure that the symbol is not used for anything > else. A note would explain that the user of the symbol should means what > was meant by a "year" - a financial house would use the symbol when talking > about calendar years while an astronomer would attach a different meaning to > the symbol. > > -----Original Message----- > From: owner-u...@colostate.edu [mailto:owner-u...@colostate.edu] On Behalf > Of James R. Frysinger > Sent: 02 April 2010 14:34 > To: U.S. Metric Association > Cc: U.S. Metric Association > Subject: [USMA:47020] Re: Correct me if I'm wrong... > > > The second is an SI unit. Minutes, hours, and days are not -- however, > they are accepted for use with the SI. So m/s is an SI unit and km/h is > not. However, both are perfectly acceptable in the eyes of the CGPM, > CIPM, BIPM, et al. > > The unit cm/min is also acceptable for use. It is very, very nearly > equivalent to the non-SI unit furlong per fortnight. > > Jim > > Stephen Davis wrote: >> ....I'm not sure on this one, so I probably am wrong but, aren't hours, >> minutes and seconds accepted as SI units anyway? >> >> If this is the case, then there's little problem with describing a >> distance as km/h surely? >> >> >> ----- Original Message ----- >> *From:* John Frewen-Lord <mailto:j...@frewston.plus.com> >> *To:* U.S. Metric Association <mailto:usma@colostate.edu> >> *Sent:* Thursday, April 01, 2010 8:52 PM >> *Subject:* [USMA:47013] Re: FW: Special Employee Advisory: Message >> from Joe Boardman >> >> Dear all: >> >> It's not often I agree with Stephen Humphreys, but on this occasion >> I think he's right. I once wrote an article for the UKMA >> Newsletter, suggesting that we might need to make more use of what I >> call the 'vernacular' in our use of SI for the everyday person. >> That using metric must become as natural as it seems for people >> brought up on imperial/USC to continue using those units. Hence I >> suggested that we could describe our height as 'one-seventy-eight' >> (1.78 m or 178 cm - your choice), our weight as 75 kaygees (I really >> hate kaygees, but recognise that it makes using metric less >> intimidating or clinical), our speed as 130 'kays' (or klicks') and >> so on. >> >> When it comes to km/h, that is what the entire world uses for >> measuring speed, rightly or wrongly. Maybe it is 'wrong', but are >> you going to change the entire world in this regard? As the US >> hardly uses metric in the everyday sense (agreed that there is a lot >> of hidden metric), then there is little chance the rest of the world >> is going to take much notice if the US starts pontificating that we >> should be using m/s rather than km/h, and even less chance that the >> rest of the world is going to actually change. >> >> Regardless of what measuring units we use, most of us relate to them >> in a comparative or relative sense only, not in absolute terms. We >> know that we take a size 8 shoe, or that we (at least the ladies >> do!) fit into a size 14 dress, and so on, without ever knowing >> exactly what those numbers mean. And we currently measure speed on >> that basis. We know (at least those of us living in those >> countries which measure our speed in km/h, which is virtually the >> entire world USA and UK excepted) that 50 km/h is a typical urban >> speed, that 80-100 km/h is a typical two lane highway speed and that >> 100-130 km/h is a typical freeway/motorway speed. We don't need to >> actually visualise how many metres per second that represents, and >> even if we did, we probably wouldn't be able to make practical use >> of it. On the other hand, when planning journeys, a typical >> suburban/rural average speed is say 60 km/h, which is 1 km per >> minute. So a 20 km journey will take 20 minutes. On longer >> journeys, where we might measure our time in hours, we might be able >> to average 100 km/h, so a 400 km journey will take 4 hours. Km/h >> allows these calculations to be made; m/s doesn't. >> >> I think if we want the general populace to embrace metric, we have >> to accept such 'vernacular' in its use. The clinically correct >> stuff we can reserve for professional usage. Oh, and as a surveyor >> working in the UK, I can assure everyone that I was indeed >> 'clinically correct' in my usage of SI in my professional work. For >> everyday usage, I find I am quite happy to 'lighten up' and use the >> 'vernacular'. >> >> John F-L >> >> >> >> ----- Original Message ----- >> *From:* Stephen Humphreys <mailto:barkatf...@hotmail.com> >> *To:* U.S. Metric Association <mailto:usma@colostate.edu> >> *Sent:* Thursday, April 01, 2010 8:13 PM >> *Subject:* [USMA:47012] Re: FW: Special Employee Advisory: >> Message from Joe Boardman >> >> I fully understand where you are coming from but even in 'fully' >> metric countries km/h is used. I cannot see that changing but >> furthermore I would not recommend pushing clinical use of si on >> non metric people. Remember that in effect you have to 'sell' >> this change so being critical about specifics should really be >> low on your priorities. Of course this just my opinion >> >> > From: mech...@illinois.edu >> > Subject: Re: [USMA:47008] Re: FW: Special Employee Advisory: >> Message from Joe Boardman >> > To: barkatf...@hotmail.com; usma@colostate.edu >> > Date: Wed, 31 Mar 2010 10:04:08 -0500 >> > >> > Stephen, >> > >> > The point you always seem to miss is that the question is not >> the traditional units habitually used since the 18 century or >> earlier, but the best units from SI for use in the future. >> > >> > ---- Original message ---- >> > >Date: Wed, 31 Mar 2010 09:07:22 +0000 >> > >From: Stephen Humphreys <barkatf...@hotmail.com> >> > >Subject: [USMA:47008] Re: FW: Special Employee Advisory: >> Message from Joe Boardman >> > >To: "U.S. Metric Association" <usma@colostate.edu> >> > > >> > > I admire your scientific brain Martin ;-) but I'll >> > > bet you a large sum of money that most (British) >> > > people would quickly understand 95 mph and have a >> > > 'feel' for what that looks like over "50 m/s based >> > > upon some maths" even though what you say >> > > technically makes a lot of sence. >> > > >> > > Of course, 'practice' often proves things and if you >> > > ever hear one of the bowlers/batters for the England >> > > and Wales side talking about fast-bowlers and >> > > spin-bowlers then you note they will always use >> > > mph. In fact my quote below about Flintoff came >> > > from an Aussie cricketer(!). Note sure whether the >> > > aussie chap in question used mph because they knew >> > > it was SkySports interviewing them or not, however >> > > whenever I have heard a feed from Australian criket >> > > games I have often heard both mph and km/h >> > > (admittedly more km/h from Australian broadcasts >> > > than mph). Incidentally they refer to km/h as >> > > 'kays' - eg "He bowled that one at 130 kays". >> > > >> > > >> > > ------------------------------------------------ >> > > >> > > From: vliets...@btinternet.com >> > > To: usma@colostate.edu >> > > Subject: [USMA:47007] Re: FW: Special Employee >> > > Advisory: Message from Joe Boardman >> > > Date: Wed, 31 Mar 2010 06:36:44 +0100 >> > > >> > > On the other hand being told that the ball is coming >> > > at you at 50 m/s and knowing that the pitch is just >> > > 20 m long tells you that you have 0.4 s to work out >> > > what to do with the ball. (A little less because you >> > > are in front of the wickets) >> > >.. >> >> > ------------------------------------------------------------------------ >> Do you have a story that started on Hotmail? Tell us now >> <http://clk.atdmt.com/UKM/go/195013117/direct/01/> > -- James R. Frysinger 632 Stony Point Mountain Road Doyle, TN 38559-3030 (C) 931.212.0267 (H) 931.657.3107 (F) 931.657.3108
