---------- Forwarded message ----------
Date: Thu, 28 Jun 2001 23:37:41 -0500 (CDT)
From: Gene Mechtly <[EMAIL PROTECTED]>
To: Ian Mills <[EMAIL PROTECTED]>
Cc: "Martin, Peter" <[EMAIL PROTECTED]>, Quinn <[EMAIL PROTECTED]>,
"Taylor, Barry N." <[EMAIL PROTECTED]>
Subject: SI Names and Symbols
On Thu, 28 Jun 2001, Ian Mills wrote:
> ... The proposal for the alternative symbols D, H and K to be allowed in
> parallel with the existing symbols da, h and k was discussed, and the
> decision was taken to make no change in the current rules for prefixes.
> ...
But the EU Directive already prescribes *only* H and K (retaining da).
How is that divergence to be resolved?
> ... The reason for making no change was that the CCU is strongly of the
> opinion that making many small changes to the SI will lead to confusion,
> and hence that it is better to make no changes unless we feel the case
> to be overwhelming.
Was the need compelling for the alternative "L" for "l" ? No!
Spelling the quantity name in full or "ml" are unambiguous in all cases.
> It is not for me to detail who spoke which way on issues of this kind.
> The members of the CCU are there as representatives of their supporting
> institutions, ... they are not present in a personal capacity.
Are CCU members (persons) publicly accountable (on record) for advocating
or opposing specific proposals?
Are institutional positions on each proposal matters of public record?
> In my last message I also mentioned the problem of the two alternative
> names "SI units" and "units of the SI", ... we felt ourselves forced to
> make a change for two reasons...
> Second, ... almost all folk ... find it extraordinary to be told ...
> that the kilometre, the centimetre, and the millimetre are not SI units.
> It seems to violate common understanding.
SI is not yet commonly understood or even taught. However, it is very
easy to teach any intelligent and attentive person that there is only
one SI unit for each physical quantity (and that decimal multiples and
submultiples are formed by application of SI prefixes), in accord with
the statement in the BIPM Brochure "It is important to emphasize that
each physical quantity has only one SI unit, ..." (Page 92, 1998)
> We therefore decided to make the change ... "SI units" and "units of the
> SI" may both be taken to refer to all the units with or without prefixes.
My hope remains that the CIPM, the CGPM, and the BIPM will reject this
distortion of the concept of coherent SI units.
Eugene A. (Gene) Mechtly
