Chemists and those in related fields started using the dalton years
before it rose to "accepted for use with the SI". My understanding is
that they petitioned long, hard, and relentlessly to get it so
acknowledged and "accepted". Science textbooks of the sort used in
introductory college or high school courses take an average of about 8
years to make it from the author's initial writings to print and the
dalton was in those textbooks for several years before it was in the
Brochure. Until the dalton was written into the Brochure, I was opposed
to its use, especially since authors never seemed to provide a caveat to
their readers about its non-SI status. I am now forced to accept it.
Proponents of the gali and the avo should anticipate at least two
decades of lobbying to get their ideas approved, I think. I do not have
a good feel for the fraction of "good ideas" put forth that actually get
accepted into the SI or even at the "accepted" level, but I suspect that
it is small. The CGPM and CIPM purposely act conservatively to proposed
changes. The stability of the SI is a valued asset in their minds, and
rightfully so. Indeed, they have a narrow set of justifications that
allow a unit to become a "derived unit with special name"; safety, human
health, etc. are the chief criteria.
Thus, the dalton only has become "accepted for use with the SI" and has
not been adopted as a specially named derived SI unit. Perhaps decades
from now it might rise to that level.
Indeed, work is in progress to substitute a standard for the kilogram
artifact, the last remaining unit standard not based on nature. Already
decades have elapsed during this work. If and when this is successful,
there may be a chance for a new unit name not involving a prefix. Thus
the gali (or one of its competitors) might ride in on the coat tails of
this new standard. And, perhaps, the avo might ride along as well. I
have a faint impression of this from peering intently into the crystal
ball I keep in a dark, back room. Also, I am reminded that "degree
centigrade" was renamed to "degree Celsius" in the same resolution that
changed the definition of the zero point of that scale in 1948.
Now, backing away from academic eagerness for elegance, let's take a
practical look at our "honey do list". High on the version of that list
that I have in hand is full metrication of the U.S. As a retired
educator, my sense is that if potential converts come close enough to
our discussions to hear us arguing about new unit names, whether the
deci and centi prefixes are acceptable or not, whether it is better to
track liters per 100 kilometers or kilometers per liter, and the like
... those potential converts will turn tail and run. As they depart they
might call back over their shoulders, "Let us know when you have
finished building this system that you want us to adopt." Indeed, that
was one of the hues and cries that probably kept Congress from adopting
metrication during the first ninety years of our country's existence.
At least on our public face (which includes the free mail list run by
the USMA) we and the SI would be more attractive to converts by showing
the benefits of the system, including its simplicity and ease of use,
than by hashing out deep doctrinal differences. Perhaps we in the USMA
should consider providing a separate "paid subscriber" list for our
exegetical esoterica. Then, the public mail list and the SI itself would
be more appealing to those thinking about metricating their personal
lives or their businesses. Sequestered meetings such as those of SCC 14
and the pages of Metrologia (and Metric Today?) provide nice places to
deal with academic discussions of elegance enhancement without scaring
off new customers. Consider the making of sausage...
Having waxed philosophic, perhaps with a modicum of accuracy and logic,
I will turn now to the more practical matter of my midday meal. I'm
thinking about having eggs and sausage. The latter will be in the form
of slices about 1 cm thick -- or 10 mm, if you prefer.
Jim
Bill Potts wrote:
Jim:
I was using SI-10 and you're using the SI Brochure. The Brochure (which I
just downloaded afresh from the BIPM site) clearly identifies the dalton as
a non-SI unit. The first paragraph on page 125, to which you refer, says the
following:
"The first three units, the non-SI units electronvolt, symbol eV, dalton or
unified atomic mass unit, symbol Da or u, respectively, and the astronomical
unit, symbol ua, have been accepted for use with the SI by the CIPM. The
units in Table 7 play important roles in a number of specialized fields in
which the results of measurements or calculations are most conveniently and
usefully expressed in these units. For the electronvolt and the dalton the
values depend on the elementary charge e and the Avogadro constant NA,
respectively."
But, as it says "accepted for use with SI," you must be right (as usual,
dammit :)).
Bill
________________________________
Bill Potts
Roseville, CA
http://metric1.org [SI Navigator]
-----Original Message-----
From: James Frysinger [mailto:[EMAIL PROTECTED]
Sent: Wednesday, June 25, 2008 15:54
To: [EMAIL PROTECTED]
Cc: U.S. Metric Association; 'Brian Leonard'; [EMAIL PROTECTED];
[EMAIL PROTECTED]; [EMAIL PROTECTED]; [EMAIL PROTECTED]
Subject: Re: [USMA:41240] RE: gali and avo
Please see the first paragraph on page 125 and note (c) to Table 7 on page
126 of the Brochure.
Jim
Bill Potts wrote:
Bruce:
There are two occurrences of dalton in SI-10, in tables A-1 and A-3.
A-1 simply gives the conversion factor to kilograms. A-3 lists it
under "Other Units."
So you're right, there doesn't really appear to be any level of
acceptance.
Bill
________________________________
Bill Potts
Roseville, CA
http://metric1.org [SI Navigator]
-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Bruce Barrow
Sent: Wednesday, June 25, 2008 14:50
To: James Frysinger
Cc: Brian Leonard; [EMAIL PROTECTED]; [EMAIL PROTECTED];
[email protected]; [EMAIL PROTECTED]; [EMAIL PROTECTED]
Subject: Re: gali and avo
Jim,
Yes, I did note the careful wording in your response to Brian. You
clearly are using some of the political skills we now see daily on TV.
In your message, you observe that the dalton "has risen to the level
of acceptance as a unit that can be used with the SI." Gee, I just
checked my copy of IEEE/ASTM SI 10, and I can't find it.
Bruce
PS. On a not-frivolous note, I believe that the 8th edition (2006) of
our BIPM bible has now become deplorably less authoritative, thanks to
the expanded Table 7 and Tables 8 and 9.
----- Original Message -----
From: "James Frysinger" <[EMAIL PROTECTED]>
To: "Bruce Barrow" <[EMAIL PROTECTED]>
Cc: "Brian Leonard" <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>;
<[EMAIL PROTECTED]>; <[email protected]>; <[EMAIL PROTECTED]>;
<[EMAIL PROTECTED]>
Sent: Wednesday, June 25, 2008 5:13 PM
Subject: Re: gali and avo
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
--
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
