Tom:
You are very right IMHO, but this is nothing new!
See my article at
http://www.metricviews.org.uk/2009/01/20/metric-user-friendly/
Cheers
John F-L
----- Original Message -----
From: "Tom Wade" <tom.w...@tomwade.eu>
To: "U.S. Metric Association" <usma@colostate.edu>
Sent: Thursday, July 30, 2009 12:10 PM
Subject: [USMA:45455] Re: Fw: default units for height
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
