On 2009/07/31, at 8:01 AM, [email protected] wrote:
Centimeters is the industry common measurement for cycling (frames)
and skiing....so I use them regularly. But this is like the
meter vs metre argument. Who cares as long as it's not inch-foot-
pounds!!!!
Dear Brian,
To answer your question – I care.
As you know people in the USA have been trying to achieve a rational,
fair, and honest measurement method since decimal methods were first
proposed by Thomas Jefferson in the 1770s, 1780s, and 1790s (as you
can see he was persistent). Jefferson succeeded with decimal currency
with help from Benjamin Franklin and George Washington but he did not
succeed in the USA with his proposal for decimal measurements.
Although Jefferson was not successful with his proposal for decimal
measurements in the USA, it is true that Thomas Jefferson with support
from Benjamin Franklin was successful in promoting the idea for a
decimal metric system in France while he was ambassador there from
1784 to 1789.
So the truth of the matter is that the USA has been trying to adopt a
better method of measuring – than the one they have now – since the
1780s.
Now you may not care that the process has taken 225 years so far – but
I do. And I find it incredibly frustrating that you can propose for
the inevitable upgrade to the metric system should take a further 100
years or more because of your conjecture that there is an equality
between metrication using millimetres or centimetres.
As a challenge, could you describe to us on this list where you have
seen a smooth, fast, economical transition to the metric system that
took less than two years using centimetres. I know of many that have
done this using millimetres.
By the way, most of my bike riding friends use millimetres for frames
and fittings except for old pre-metric specifications of some threads
on old bikes. It is interesting that people who are developing new
ideas for bikes in the USA routinely use millimetres: See http://www.freepatentsonline.com/5842712.html
and http://www.patentstorm.us/patents/5842712/description.html It
may be that the centimetres you have met are part of a dumbing down
process specifically for sales in the USA because bike sales staff
don't have any industry guidance on which is best to use what to use –
centimetres or millimetres.
With respect to skis, the transition from old pre-metric measures
began in Switzerland and France following the 'International metric
conference' held in about 1798/1799. Given that it is possible to make
a metric transition in two years using millimetres this would mean
that the ski industry was able to do this by 1801. We know that this
didn't work in France until 1840 at least and, without knowledge, I
suspect that a similar time lag was also true of Switzerland.
Cheers,
Pat Naughtin
Author of the forthcoming book, Metrication Leaders Guide.
PO Box 305 Belmont 3216,
Geelong, Australia
Phone: 61 3 5241 2008
Metric system consultant, writer, and speaker, Pat Naughtin, has
helped thousands of people and hundreds of companies upgrade to the
modern metric system smoothly, quickly, and so economically that they
now save thousands each year when buying, processing, or selling for
their businesses. Pat provides services and resources for many
different trades, crafts, and professions for commercial, industrial
and government metrication leaders in Asia, Europe, and in the USA.
Pat's clients include the Australian Government, Google, NASA, NIST,
and the metric associations of Canada, the UK, and the USA. See http://www.metricationmatters.com
for more metrication information, contact Pat at [email protected]
or to get the free 'Metrication matters' newsletter go to: http://www.metricationmatters.com/newsletter
to subscribe.
-------- Original Message --------
Subject: [USMA:45469] centimetres vs millimetres
From: Pat Naughtin <[email protected]>
Date: Thu, July 30, 2009 2:50 pm
To: "U.S. Metric Association" <[email protected]>
Dear Tom,
I take exception to the expression, anti-centimeter prejudice.
As you know, I am opposed to the use of the centimetre in almost
all* practical daily calculations, but this is not on the basis of
an anti-centimeter prejudice.
My opposition to the centimetre is based on observations of
metrication transitions. I simply observed that metrication using
millimetres can be done quite quickly, smoothly, and with so little
cost that savings are made almost as soon as you begin the
metrication process. On the other hand, the attempts at metrication
using centimetres are slow – painfully slow, rough – often involving
bitter disputes about the 'right' way to go about metric conversion,
and so expensive that these metric conversion attempts are often
abandoned with the thought best expressed as: 'Never again!'
As you may recall, I did not understand why it was so much better to
choose millimetres rather than centimetres for your inevitable
transition to the metric system, so I involved myself in any debates
and discussions that I could to collect the arguments both for and
against millimetres and centimetres that I could find. My collection
of these thoughts is available from http://www.metricationmatters.com/docs/centimetresORmillimetres.pdf
and I know that it is rather long because I tried to be exhaustive
to be fair to both sides of the argument.
* I sometimes – rarely – use centimetres as the basis for cubic
centimetres to get the volume of things like a home aquarium in
millilitres. However, this does not justify, in my opinion,
condemning an entire nation to something like 100 years of metric
conversion using centimetres when I have seen the the whole job done
in a day using millimetres. As you know the USA were world leaders
in measurement reform from the 1770s to the 1790s but they have not
yet succeeded in fully adopting the decimal metric system that they
had played such a big part in producing. See http://metricationmatters.com/USAmetricsystemhistory.html
for a short summary of this history
Cheers,
Pat Naughtin
Author of the forthcoming book, Metrication Leaders Guide.
PO Box 305 Belmont 3216,
Geelong, Australia
Phone: 61 3 5241 2008
Metric system consultant, writer, and speaker, Pat Naughtin, has
helped thousands of people and hundreds of companies upgrade to the
modern metric system smoothly, quickly, and so economically that
they now save thousands each year when buying, processing, or
selling for their businesses. Pat provides services and resources
for many different trades, crafts, and professions for commercial,
industrial and government metrication leaders in Asia, Europe, and
in the USA. Pat's clients include the Australian Government, Google,
NASA, NIST, and the metric associations of Canada, the UK, and the
USA. See http://www.metricationmatters.com for more metrication
information, contact Pat at [email protected] or
to get the free 'Metrication matters' newsletter go to: http://www.metricationmatters.com/newsletter
to subscribe.
On 2009/07/30, at 9:10 PM, Tom Wade wrote:
It is good of you to promote metric height numbers.
However, I do not like centimeter.
I want schools to stop teaching and using centimeter.
I also want schools to stop teaching inch-pound numbers.
So, I want height to be in millimeters.
What is it with the anti-centimeter prejudice that many people have
on this group ?
Just because mm are more appropriate for nearly all industrial use
doesn't mean the humble cm doesn't have a role. To place cm
alongside inch-pound as in the above paragraph is way over the top,
and to try and pretend that that units between kilo and milli don't
exist is to miss out on a huge advantage of the use of metric
prefixes: the ability to scale the unit to the most appropriate
size (and to advocate not teaching a unit that is not only
officially recognized but is in wide use internationally simply
because purists have a dislike of them is to recommend leaving
holes in young people's education).
The fact is that cm *are* the most appropriate unit for people's
height. If you don't like using cm, then quote your height in
meters (which is effectively 'hidden centimeters' as you will
typically quote it to two decimal places, i.e. centimeters). Thus
the centimeter is the unit that is closest to the required
precision for people's height. It also gives a nice manageable
range of whole numbers.
My height is 174 cm or 1.74 m. If I am writing it down, I may
write '1.74 m', but in saying it, I will say "one seventy four"
without any units, which can be understood as one hundred seventy
four centimeters or 1 meter plus 74 centimeters.
Quoting height in millimeters is simply plain stupid - height is
never expressed with that precision, as something as simple as a
haircut will change your height. People who insist on using mm for
height are like people who are so impressed with a screwdriver as a
tool, that they think it can be used for everything (whereas a less
generally useful tool such as a hammer would be more appropriate
for *some* applications). I doubt very much you will see mm being
used for height in countries where metric is the system used.
Also, using mm for height gives an unnatural feeling, rather like
the putative "New York 96.56 km" sign that anti-metric activists
insist would replace a more natural "60 mile" sign.
As for the choice of using meters or centimeters, I would point at
that the use of centimeters has the advantage of yielding a whole
integer without the need for decimal places -- something that is
often (quite correctly) pointed out by people recommending the
advantages of mm over inches or centimeters in other applications
such as engineering drawings. Why not apply the same logic here ?
Use the unit that is best suited to the range and precision
required by the application.
Tom Wade
