Re: [Phys-l] SI unit for time

[John Denker <jsd@av8n.com>]

On 09/06/2008 11:19 PM, Julie Quah wrote:
> i notice that the unit for time is still very much written as sec instead of
> s, even in reputed Physics website. Anyone can enlighted?

The canonical abbreviation is of course "s".

 According to 
    http://physics.nist.gov/Pubs/SP330/sp330.pdf
 "It is not permissible to use abbreviations for unit symbols or 
  unit names, such as sec ...."


As the next step, if we are seeking enlightenment, the remaining
question is "why"?  Why should we worry about this at all?  I
don't like to tell students "do this because I said so" or
"because BIPM said so".

  The devil's advocate would point out that NIST and/or BIPM are 
  not going to arrest you for "impermissible" abbreviations.  As
  for the "sec" abbreviation in particular, it has been in use 
  for thousands of years, and is "still very much" in use.  

  "Sec" is not even illogical:
   *) It agrees with "min", which is the canonical abbreviation
    for minute.
   *) It has the advantage of being distinct from the "s" that
    marks a plural in English (and some other languages).
   *) Sometimes abbreviations become words in their own right.  
    The expression "Wait a sec" may be informal, but it is 
    perfectly grammatical.

Switching now to the other side of the argument:

The usual reason for preferring the canonical abbreviations is 
that the non-canonical ones are sometimes a burden on readers
who don't speak your language fluently (or at all).  Hence the
editors at international journals such as Phys. Rev. are going
to insist on "s".  They have to draw the line somewhere.

As for web sites in particular, realize that the WWW really is
the World Wide Web.  My web site logs report lots of hits from 
really out-of-the-way places.