RE: S.I. (don't believe everything you read)

["L. R. Cartwright (Larry)" <physics@scnc.cps.k12.mi.us>]

I am trying to compile a short "Don't Believe Everything You Read" list of
errors made by "authoritative sources", textbooks, publications, etc, to
replace a hopelessly outdated list I pitched.  I would be grateful for any
contributions suitable for a fairly bright high school audience,
especially of any incorrect "scientific" information you have run across
on the internet. Or sweeping generalizations that are only partly true and
therefor suspect. 

For example, and with all due respect to David Bowman (and the gods know
there are few whose knowledge and talent I respect more than David's), I
approach NIST Special Publication 811 with more caution since running
across an error at <http://physics.nist.gov/Documents/sp811.pdf>; perhaps
this does not appear in the hard-copy edition: 

"B.7.1  Rounding Numbers ...
(1) If the digits to be discarded begin with a digit less than 5, the
digit preceding the 5 is not changed. ..."

I know it's not a big deal that there is one incorrect statement in an
83-page document;  but I was pleased to have an up-to-date example to use
with my repeated warnings to my students,
(1) Don't believe everything you read or hear,
    no matter how ostensibly authoritative the source.
(2) Even "experts" make mistakes.
(3) Any and every piece of *important* information
    needs to be independently verified." 

With thanks in advance for any contributions to my list,

Larry

------------------------------------------------------------ 
Larry Cartwright 
Physics, Physical Science, Internet Teacher 
Charlotte High School, 378 State Street, Charlotte MI 48813 
<physics@scnc.cps.k12.mi.us> or <science@scnc.cps.k12.mi.us>
------------------------------------------------------------
Apologies for cross-posting my request.
Thanks for your patience.
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On Fri, 25 Sep 1998, David Bowman wrote:

> To help confuse the issue let me point out that according to the NIST's
> Special Publication 811 the avoirdupois pound is defined to be *exactly*
> 0.45359237 kg of *mass*.  A 1 pound force (lbf) is the weight of a
> 1 lb mass in a standard gravitational field.  *If* this standard field
> strength is taken as the 'official' value of 9.80665 m/s^2 then a 1 lbf
> corresponds to *exactly* 4.44482216152605 N of force.