Bruce,
Please note that I did not agree with Brian about the need for new
names. I merely said they were the best proposals I had seen to date.
I also pointed out the process of making such a change and cautioned
that it was a long, arduous road. Hopefully all concerned figured out
that there wasn't a snowball's chance on a Tennessee summer afternoon of
the changes being approved. That said, in the past I made remarks
similar to yours here, but about not needing the dalton. Now it has
risen to the level of acceptance as a unit that can be used with the SI.
So much for my opinion!
Rest assured that CIPM and CGPM will not take USMA discussion on the
matter as the basis for deciding what to do about the unit name for
mass. "L'gran K" will live on in name, if not in artifact. (But we may
have to live with watts in the balance.)
In the meantime I hope to have enlightened some folks about the process
of effecting changes to the SI -- and the minuscule likelihood of being
successful. The endless banter on the USMA mail list (this thread
started before I joined USMA in 1990, I think) is indeed more of an
academic aerobics exercise than an effective course of action. I find it
a refreshing relief from the endless argument about the centimeter.
Jim
Bruce Barrow wrote:
Dear Jim,
Good #$&*% grief! We do NOT need a new name for the kilogram. We do
NOT need to advocate changes in the SI. We need to teach the metric
system and expand its use in the US. People here know what a kilo is;
let's not confuse them.
Bruce Barrow
----- Original Message ----- From: "James Frysinger"
<[EMAIL PROTECTED]>
To: "Brian Leonard" <[EMAIL PROTECTED]>
Cc: <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>; <[email protected]>;
<[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>
Sent: Wednesday, June 25, 2008 12:09 PM
Subject: Re: gali and avo
Dear Brian,
These are the two best proposals I have seen to date.
One should be braced; it takes a very long time for proposals to wend
their way through the administrative process to become approved.
Consider how long it took for the dalton (Da) to obtain approval. The
pathway is via the Consultative Committee on Units (CCU) and SCC 14
("stds-units") has a healthy connection to our country's CCU. Perhaps
your proposals could find some discussion at our next SCC 14 meeting
as a possible proposal to CCU. Publication of appropriate papers in
Metrologia might be beneficial to your cause as well.
regards,
Jim
Brian Leonard wrote:
Dear Howard:
Thank you. You are absolutely right. For a long time I've been
advocating the name gali (symbol G), honouring Galileo--as he was the
first ("modern physicist") to explore both the inertial and
gravitational properties of mass (although, of course, he didn't
speak of them in these terms). His experiments and insights were
essential for Newton's laws; in fact, Galileo already had "Newton's
first law."
This is not some mere whim. The idea of honouring an appropriate
scientist is well established. The symbol (capital) G is also
appropriate. The unit gauss is no longer in use. [Some have
suggested giorgi (also symbol G), honouring the founder of the "MKS"
system, known for cleaning up mechanical, thermal and electrical
energy concepts--I find this a bit "awkward."] I have no trouble
keeping gram (symbol g) defined as (exactly) one milligali: g =
mG. Here's the "delicatessen test":
I would like half a gali of roast turkey and two hundred grams of
Swiss cheese. [1/2 a G of roast turkey and 200 g of Swiss cheese.]
Checkout scales would register in G to three decimal places--as they
do now (in kg) in metric countries. Labelling would have to be
precise in distinguishing between G and g--but this distinction
between capital and lower-case HAS to be cleaned up anyway!
This flows nicely--because in most metric countries a kilogram is
referred to as a kilo ("keeloh"); and gali ("galley") is phonetically
very close to this. [I don't think I could stomach half a giorgi of
roast turkey.]
Also, chemists are never going to give up working (and thinking and
communicating) in grams and moles--see below. SI submultiple
prefixes can be used--even though that's an SI "no-no"! But we have
no trouble doing submultiple and supermultiple SI prefixes with
liter. [An appropriate name for a cubic meter (and a square meter)
is another concern.]
I also have no trouble with tonne (symbol t) defined as (exactly) one
kilogali: t = kG. [Pronounce it as "tunn" rather than "tonn."
Other tons will drop by the wayside.] It's handy for large
commercial masses. SI supermultiple prefixes can be used with
this--even though that's also an SI "no-no"!
Getting back to the chemists, the kilomole--renamed the avo (symbol
Av), honouring Avogadro for obvious reasons--should be the BASE unit,
thereby avoiding the ridiculous situation of having the amount
specific mass (not "molar" mass) of, for example, carbon 12 be 0.012
kg/mol when expressed in base units. In the new base units, it would
be 12 G/Av (12 gali per avo). This avoids factors of ten to the plus
or minus three popping up all over the place in theoretical
equations. The mole (and SI submultiple prefixes) would still be
used by chemists; one mole being defined as (exactly) one milliavo:
mol = mAv.
By the way, dalton (Da) is used as an (accepted) alternative to
"unified atomic mass unit" (u). SI units or units in use with SI
should not have multi-word names (metric ton, etc); what is a ku?--a
kilo-unified atomic mass unit: an atomic mass unit unified a thousand
times? A kilodalton (kDa) is well defined.
Cheers,
Benny Leonard.
On Jun 23, 2008, at 6:57 PM, Howard Hayden wrote:
Hi Stan,
Gee, I thought a short ton was 2 million millipounds. This is the
problem you face when the UNIT of mass has a prefix meaning a
thousand, namely the kilogram. So, a metric ton becomes a million
millikilograms, for that is exactly the meaning of megagram.
If the SI committee wants to do something truly useful, it would be
to RENAME the kilogram so that it has no prefix. Call it the
Jakuba, the Washington, the Brenner, the FMU (French Mass unit), the
SIMU (SI Mass Unit), the Dalton, the Mach, the Einstein, the Cagey,
or SOMETHING!!! This simple naming problem has been in the works for
a half-century. Get on with it! All you've got to do is choose a
name. Why should that take decades?
Look at it this way. You're trying to get the whole world to quit
using the word /tonne/. It should be much easier to get the
standards committees to quit using the long-outdated term
/kilogram/, and instead to use a non-prefixed name. That would
remove an obnoxious exception to SI. Now that the shoe is on that
foot, just who is it that's suffering from hardening of the categories?
SI got rid of a large number of past units, among them gram-force,
kilogram-force, Gauss, Gilbert, Oersted, slugs, poundals, and
probably others, and for good reason. Why not do the right thing
and get rid of the term /kilogram/?
The Megagram is NOT unambiguous. Students are forever getting
confused about this issue. (Try teaching a bunch of students that a
megagram is a million thousandths of the unit of mass in the SI
almost-system. They'll think you're nuts, and they'll be right.)
Teaching would be much easier if the same mass were called the
kiloEinstein (or kE).
I have no sympathy whatsoever for the term /megagram/. It is NOT a
million mass units. The term /tonne/ has been in use by the French
for over two centuries, and it at least relates /directly/ to the
mass unit (1000 kg), unlike the indirectly related megagram
(1,000,000 milli-kg).
It's time for SI to clean house and get rid of that Mg abomination.
Cheers,
Howard
------------ Howard Hayden [EMAIL PROTECTED]
<mailto:[EMAIL PROTECTED]> /The Energy Advocate/
www.energyadvocate.com <http://www.energyadvocate.com/>
--
James R. Frysinger
632 Stony Point Mountain Road
Doyle, TN 38559-3030
(H) 931.657.3107
(C) 931.212.0267
--
James R. Frysinger
632 Stony Point Mountain Road
Doyle, TN 38559-3030
(H) 931.657.3107
(C) 931.212.0267
