Subject:
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Re: the metric system
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Newsgroups:
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lugnet.off-topic.debate
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Date:
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Tue, 1 May 2001 15:39:20 GMT
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Viewed:
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323 times
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In lugnet.off-topic.debate, Lester Witter writes:
> ....
> > Anyways, I'm in complete agreement with the "yea" argument.
> > But as someone else has mentioned, the conversion is now
> > immobile, fixed at (in the example given) 1"=2.54cm (approx).
> > ...
>
> I recently had to do somethin involving metirc conversion and was told that at
> some point the inch was redefind by the international standards people to be
> exactly 2.54 cm.
Really? Cool! Maybe the Euro will be NGL 2.20 one day, and
not NGL 2.203. ;) I know, immaterial, given that the Guilder
shall cease to exist on 1 March 2002.
> > The last time, IIRC, that the meter changed definitively
> > was 1873. I think it got its current measure--based on the
> > speed of light, which had, ironically, originally been determined
> > by the standard bar in Paris--came into being recently, but the
> > goal is still that standard manufactured in 1873 under 'ideal'
> ....
n.b.: 1872 was the actual Conference that made one particular
meter bar the standard.
> I thought that the meter was defined in terms of the wavelenght of Krypton (the
> gas not the planet) as measured by a laser under specific controlled
> conditions. This definition must have been introduced after the invention of
> the laser in the fifties.
The wavelengths of krypton were an old standard. James Clerk
Maxwell (the mentor of my PhD thesis protagonist, Sir David Gill)
offered the wavelength of sodium as a measuring standard as early
as 1859, but the Krypton standard wasn't adopted until 1960. The
light standard became "official" in 1983. The official length
of the meter is the distance covered by light in 1/299,792,458
of a second, the reciprocal of the speed of light in m/s.
The first standard, however, was based on the size of the Earth,
something that itself is still under revision (WGS84 being the
latest--1984--geoid, IIRC).
> Just to keep the holy wars going, the big deal about the metiric system is
> everything is based on 10. The yard is based on 36. One observation (let the
> flames be lit) is that 36 has a whole bunch more integer divisors that 10. You
> can have 1/2 1/3 1/4 or 1/6 1/9 or 1/12 of a yard in whole sub-units. Also
> sub-units of an inch are binary, (1/2 , 1/4, 1/8 etc) which is easy to mark
> when you are cutting something (woodworking reference). It can be awkward to
> make a 1/4 (or worse 1/3 scale) example of something give in metric.
>
> He who is about to be flamed salutes you
Aye-aye, cap'n! ;) An argument for binary has been made, and
it's got some compelling points, IMHO. I'd love to see a study
of people doing mathematics in their head and the speed at which
they do division in the US versus more "progressive" lands. On
the other hand, the learning curve is miiiiighty steep, and just
make sure that rocket is rated in newtons, not foot-pounds. Ack.
By the way: at the beginning, because of its French Revolutionary
connotations, one could go to jail or be flogged for espousing
the System Internationale. This was true in Britain until nearly
the middle of the nineteenth century, and it wasn't legalised in
the US until after the Civil War.
best
LFB (does this need to go over to .geek?)
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Message is in Reply To:
 | | Re: the metric system
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| .... (...) I recently had to do somethin involving metirc conversion and was told that at some point the inch was redefind by the international standards people to be exactly 2.54 cm. (...) .... I thought that the meter was defined in terms of the (...) (24 years ago, 1-May-01, to lugnet.off-topic.debate)
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