"Mark Rand" wrote in message
...
On Mon, 24 Sep 2007 09:43:25 -0400, "Ed Huntress"

wrote:



I'm tempted to summarize what we've been saying but it would be too
involved. The point is that the SI has been a big disappointment to those
who thought it would take over completely for other measuring systems.
There
are several reasons it hasn't, the primary ones being the clumsiness of
multi-dimensional units when all you're doing is adding and subtracting
them
(the vast majority of everyday calculations); the fact that the
multi-dimensional units tend not to have an analogy that can be
experienced
by the senses; and the fact that for dimensional and volumetric
measurement,
experience has shown that it rarely matters what base you use for units.



NITPICK

kg==single dimensioned unit
m==single dimensioned unit
s==single dimensioned unit

Just about all of the rest (Ampere, Tesla, Newton, Stokes, Joule etc. ad
infinitum are multi-dimensional.

Jeez, not *all* of them are multi-dimensional. Just enough to thicken the
whole process of using them in everyday measurements.

A lot of multi-dimensional SI units are the consequence of the system's
minimalist approach: when you use fewer base units, more of the derived
units have to combine more than one base unit.


/NITPICK

Note that Nick has been just about the only one to correctly capitalise
Calorie to indicate the kilo calorie as used in food. Why aren't
McDogBurgers
measured in BTU's? :-)

But Nick also is the one who leans on the fact that the calorie is not a
legal SI unit. d8-)

--
Ed Huntress