You folks may be interested in this additional information from Mario
Iona, who used to have a regular column in TPT titled "Would You Believe".
On his question of me being the editor of the VECTOR, I must plead guilty.
On the matter of abbreviations vs. symbols, I was actually quoting from
the SUN official document, so am not responsible for their misuse of the
terms. I agree with Mario 100%, though. We should *not* call s the
abbreviation for second, it is the *symbol* for it, and that's another
reason no full stop is required.
-- Donald
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Dr. Donald E. Simanek Office: 717-893-2079
Prof. of Physics Internet: dsimanek@eagle.lhup.edu
Lock Haven University, Lock Haven, PA. 17745 CIS: 73147,2166
Home page: http://www.lhup.edu/~dsimanek FAX: 717-893-2047
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e-mail to Dr. Donald E. Simanek.
Lock Haven University
Lock Haven, PA 17745
<dsimanek@eagle.lhup.edu> 3 March 1997
One of my colleagues gave me your response about spelling of units and
related matters (MHO to Simens) on the internet on Sat March 1. I am not
involved with these internet information and misinformation networks, but
I have joined the modern age by corresponding occasionally by e-mail.
I would like to add my 2-cent-worth to your comments.
I have not checked with the Handbook of Physics and Chemistry. The
official rules for SI (International System of units) are fairly clearly
stated in the NIST Special Publication SP330. This is basically a
translation of the French official publication issued by the
international committees formulating and revising SI. It has a few
official differences for the US (such as decimal point rather than a
comma, a few spelling changes etc.). It also contains the few rules from
the French document that SI adopted from ISO, which thereby became SI
rules. (It makes it a little fuzzy what to do with other ISO rules not
clearly adopted by SI.) There are also uses in SP 330, which are not
based on explicit rules, but tend to become "SI rules" by use rather than
decree. For example "degree Celsius" is spelled with capital C, in
apparent conflict with the rule that units named after persons should be
spelled with lower case.
Since there exists the "official" version of SI, there is no need for the
professional societies to create their own versions of metric units. (But
some do adopt rules that are in conflict with SI, others are extensions
applicable in special domains.) The AIP Style Manual has many but not all
of the SI rules. The recent annual Buyers Guides by AIP have, in the
introductory pages, good summaries (by Robert Nelson) of most SI rules.
In your response you use the terms abbreviation and symbol
interchangeably. The symbols are not abbreviations and therefore there is
less temptation to use a period after them and plural "s".
Double prefixes are not allowed is SI; and your statement "when single
prefixes are available" is not a valid qualification.
The "fermi" is not a SI unit; that should preclude all further
discussions. Since fm (femtometer) is available there is no need to
consider the fermi. It is specifically mentioned in the official SI
documents as a "unit generally deprecated", which mean should not be used
with SI.
I am afraid one has to accept the liter as a metric unit, but it is not a
SI unit (unfortunately it has been admitted to be used with SI, but not
for precision data). I would advocate the use of the cubic-decimeter,
when looking for an alternative (the cubic-meter is 1000 times bigger).
I am afraid I can not follow your argument why density is not a ratio.
What is the basis for claiming that ratio's have to be without (net) units?
I agree that units and dimensions are not synonyms. However since a
choice for base units has been made in SI it is often convenient to use
the same quantities a basis for dimensions, and then there is very little
difference left, except notation.
Are you the author of VECTOR fame, with whom I corresponded about 20
years ago? Or am I confusing names?
Sincerely,
Mario Iona.
Department of Physics and Astronomy, University of Denver, Denver, CO.
80208-2238. (303) 744-0696; (f) (303) 871-4405. <miona@du.edu>