On Thu, 13 Nov 2003 18:33:15 -0500, "John Gilmer"
wrote:



There is NOTHING magin about the metric system except for the fact that
units differ by powers of TEN.

Apart from the minor fact that almost everyone (19 out of 20 people
on this planet) uses it, you mean?

Gosh!

Well, sport, 49 out of 50 people (on this planet) don't qualify for Mensa.


And of course the fact that it is a coherent system, without a need
to memorize any unit-specific conversion factors in physics formulas?

Un huh.

You HAVE heard of the kilogram FORCE

unit, haven't you?

I've heard of it. The CGPM endorsed it, and made it well defined for
the first time (at a time when pounds force had also never been well
defined), way back in 1901 by adopting a "standard acceleration of
gravity," a concept of metrology and not of physics, something which
serves no other purpose than to define a unit of force based on a unit
of mass. BTW, nobody in the U.S. and perhaps not anywhere else has
ever officially adopted an official value for the purpose of defining
pounds force.

That kilogram force (aka kilopond) is not part of the International
System of Units. The vestiges of its use should be eradicated; Japan,
one place that still had significant use of this obsolete unit, made a
concerted effort to get rid of most of its use a few years ago.

That's another important thing about the metric system--it is the only
system today that is still fully supported and updated. Anything else
is like old, orphaned software.

Nobody will ever bother telling us to quit using using pounds force,
without telling us not to use pounds of any sort. That system is no
longer updated.


And of course the fact that a surprising number of useful everyday
quantities such as

- earth gravity (~10 m/s^2)

Well, in "English" its 32 ft/s^2 and 32 is a power of 2 (isn't "binary" more
"rational" than decimal?).

- water density (~1000 kg/m^3)

A pints a pound the world round!

That never was true, even if the "world" stops at the U.S. border.

Check this out:
http://w0rli.home.att.net/youare.swf

A cubic foot of cool water equal to 1000 oz avdp is an accident that
is much closer to true.

(64 lbs/ft^3) (IOW another power of t
wo)
- length of equator (~40000 km)

So? in English its about 25,000 miles.

Which miles? How many feet is that?

- speed of light (~300000000 m/s)

So? 186,000 miles/second!

- atmospheric pressure (~100 kPa)

14.5 psia

Sure. Real handy. But what is it in inches of mercury, the units the
National Weather Service uses for atmospheric pressure? How do you
convert between your "psia" and those inches of mercury? How can you
remember which one is 14.5 and which one is some other number?

- recommended serving temperature of American soft drinks (0 deg C)

Or 32 F (another power of two).

Well, if you think that you can multiply and divide a temperature in
either degrees Fahrenheit or degrees Celsius by some number and get
anything meaningful, you really are stupid. Powers of two are of no
significance.

- recommended brewing temperature of English breakfast tea (100 deg C)

But coffee (which AMERICANS prefer) is best brewed at 200F.


etc. happen to to be within about 1-2% of a round number, making
the metric system unbelievably convenient for quick estimates
with mental arithmetic.

Not to forget convenient approximations such as

- length of an adult's step (~1 m)

Well, a mile is 1,000 paces of your standard Roman Legionair type!

After a switch to apply to a longer pace of 5 English feet, before an
additional 280 feet were gratuitously added by Elizabeth I, to make it
come out to a whole number of furlongs in a different system of units.

- width of an adult's hand (~0.1 m)

Length of an adult's foot is ONE FOOT.

- width of the nail of the small finger (~0.01 m)

ReallY? Thumb join is 1".

- an hour's drive by car (100 km)

Well, for most drivers who "bend" the limit just a "little", its 64 miles
(another power of 2).
- an hour's walk (10 km)

More like 3 MILES.

Can you name even a single country that adopted its customary
units from the US?

Who cares?

There is at least one, of course. Its capital is named after our 5th
President. Aren't you swelling with pride that they followed our lead
in their units of measure?

Gene Nygaard
http://ourworld.compuserve.com/homepages/Gene_Nygaard/