In my first test in the physics class at University we were set a problem
involving Bernoulli's equation of fluid flow. There was a real mish-mash of
units - inches, centimetres, metre/second, pressure in psi, accelatation due to
gravity as 9.8 m/s^2 and so on. The test was to see who had the sense to
reduce everything at a compatible set of units. Very few student got it right
and since we wer ein teh top tutorial group (everybody in our group having gat
an "A" at secondary school) we had a right dressing down from the professor. I
will never forget it.
I now explain it as "Je ne par mix mon units" or "Ich mussen mir units nicht
mixen" Perhaps the American version would replace the French or German with
Spanish.
----- Original Message -----
From: Mike Millet
To: U.S. Metric Association
Sent: Wednesday, January 17, 2007 4:09 PM
Subject: [USMA:37764] RE: piecemeal metrication
I agree that the best transition is a fast one but you won't find a president
on either side of the aisle that is willing to be brave enough to change
"everything" at once. Maybe a few things like metric only package labelling and
even switching to Celcius but no president is going to push for metrication
during his four year term even though it's doable. They'd have to have
tremendous political capital and be able to cast it in such a good light that
every American would agree it's a good thing to do and as many of us know
getting Americans to agree about anything at all is nigh on impossible :).
Besides, I would foresee that if the presidential administration DID switch
to SI totally during that four years the one after him would champion "Going
back to the grassroots that America was founded on" and start rolling back the
changes.
The only way to set the law in stone towards SI is to do it gradually until
people think that there has never been anything but that and they're used to
it. We may even have to go so far as letting the contractors that build our
roads do so in feet and inches provided they sign them in meters and kilometers
until the generation of engineers that prefer and have fought the government on
that retires and a newer one can take its place. Old habits die hard.
We had a maths class that brought this up the other day. The question was
something along the lines of "Find the vertical clearance of a 2km long pipe
that has an eight percent slope" I did it and came out with 160m vertical
clearance from beginning to end.
Out of the class of 30 students, I was one of perhaps 2 or three people who
even knew what a meter was. Of course in Idaho teaching metric is mandated but
most teachers simply ignore it or brush over it. About half the studen'ts
asked the professor if we would be tested on metric equations and he said yes.
He then encouraged us to learn the conversions between meters and kilometers
etc. The 20 or so students that were asking the question then asked him if it
would be okay if they converted the answer to inches and feet and solved it. He
of course replied no because that's not the format the question was in and
furthermore we should all know the conversions anyway for our own good.
Thus ensued a ten minute long debate about how "This is America and we do
things this way" etc :). Several of the students made up their minds to
convert any SI unit they saw to the equivalent USC and then work problems that
way no matter how messy or complicated it got and threatened the teacher with
being dragged in front of a review board if he dared to mark them wrong for not
being in the correct units.
This is an extreme example but it makes the poiint that there are still
strong pockets of resistence to overcome. I felt bad for my professor having to
explain all this and then getting verbally chewed out for it but I think he'll
stand his ground on the issue. Hopefully the rest of us can do the same and we
can keep the ball rolling in the right direction.
Mike
Mike
On 1/16/07, Linda D. Bergeron < [EMAIL PROTECTED]> wrote:
I am going to have to agree with Bill on this one. The US has had 30 years
to convert 'slowly'. Not only has it not done so, there are areas of
backslidding. For instance several years ago, at my local Wal-Mart you could
find all kinds of metric measuring cups and scales. Now most everything of that
sort has gone back to Fred Flintstone Units.
Thus we have seen the "slow" way does not work. Congress needs to get off
its duff and carry out its constitutional duty and designate the metric system
as the only lawful system for the US, effective by a specified date. And then
have the political guts to stick by it when this or that special intrest
screams boldy murder.
Although I do not see that happening anytime soon. Even with the Democrats
in control of Congress.
Linda Bergeron
--------------------------------------------------------------------------
From: Bill Hooper <[EMAIL PROTECTED] >
Reply-To: [EMAIL PROTECTED]
To: "U.S. Metric Association" < [email protected]>
Subject: [USMA:37754] piecemeal metrication
Date: Tue, 16 Jan 2007 12:49:20 -0500
On 2007 Jan 16 , at 8:38 AM, Mike Millet wrote:
That's why the best and smoothest transition in the US ... (will be) ...
rather from slow gradual economic and societal change.
"Slow" and "gradual" means difficult and expensive. During a long, slow
transition, both the old and new systems would be in effect causing a great
deal of confusion and extra work. Furthermore, when two systems are both in
effect, people would tend to continue using the old, familiar system. They
would not "gradually become familiar" with the new one.
Mike goes on to say:
give the US consumer some time ... (to become accustomed to dual
labeling) ... then gradually introduce temperature and fuel and finally road
signage changes.
It's difficult to change one things at a time because there are so many
interconnections between units. If one changes fuel measurement at one time and
road signage (including distance) at another time, when do you change fuel
economy figures from miles per gallon to kilometres per litre (or litres per
100 kilometres)?
Do you first change from miles per gallon to miles per litre (when litres
are adopted) and then change from miles per litre to kilometres per litre at a
later time (when kilometres are adopted). That would mean having to make TWO
changes instead of just one for fuel economy alone (in addition to the
necessary changes from gallons to litres and from miles to kilometres.
Thus, instead of making a total of three changes at one time:
gal. to L,
mi. to km,
mi/gal to km/L
you'd have to make FOUR changes spread out over an extended period of
time:
gal. to L,
mi./gal. to mi./L,
mi. to km,
mi./L to km/L.
Another example would be cooking times based on oven temperature and
amount of food. We have charts or directions in Fahrenheit and pounds; we will
need to get to Celsius and kilograms.
Do we make TWO changes, first from Fahrenheit+pounds to Celsius+pounds
and later a second change from Celsius+pounds to Celsius+kilograms? How foolish
when we can do it in one change if we convert all things simultaneously.
There are other relationships that cause would cause problems, too. We
know (actually I had to look up this first one) that there are 231 in^3 in a
gallon and 1000 cm^3 in a litre. If we convert volumes from gallons to litres
before we convert inches to centimetres, then in the interim (when we are using
litres and inches), do we need to know how many cubic inches there are in a
litre? (The answer is 61.023 7441, by the way.) Again, MORE conversions are
needed when changes are made in several steps instead of all at once.
Regards,
Bill Hooper
Fernandina Beach, Florida, USA
==========================
SImplification Begins With SI.
==========================
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