Re: Definitions

[John Denker <jsd@MONMOUTH.COM>]

At 09:49 AM 10/28/00 -0500, Glenn A. Carlson wrote:
> I'll back up a bit to offer a couple of situations in which arguing
> about definitions is not mere bickering.

> ... When someone talks about "static equilibrium", but cannot
> distinguish static equilibrium from non-static (dynamic?) equilibrium.

I agree that "dynamic equilibrium" is an ugly and unhelpful term.

Constructive suggestion:  When somebody starts talking about "dynamic
equilibrium", try to steer the conversation toward three different terms
for three different concepts:
        * equilibrium
        * stability
        * damping
For example:
  http://www.monmouth.com/~jsd/how/htm/equilib.html


General remark:  On some occasions, bickering is pointless and merely a
symptom of somebody being in a bad mood.  But on other occasions, what
passes for a terminological dispute is a symptom of deep genuine confusion,
without any ill will.  In many cases, the root of the problem is that
people have in their mind two or more concepts, and can't clearly
distinguish the concepts because they share the same name.  Delineating the
various concepts and finding distinct names for them is a big help.

> ... When someone talks about a "generalized rotation," but does not
> define what that term means.

Why the continued griping against "generalized rotation"?

Why does it not suffice to use the dictionary definition of "rotation"
  http://www.m-w.com/cgi-bin/dictionary?va=rotation
and of "generalize" (in the transitive sense)
  http://www.m-w.com/cgi-bin/dictionary?va=generalize
especially definition 2a:
  "to derive or induce (a general conception or principle) from particulars"

It won't do to claim that the rotation operator can't be generalized;  spin
and isospin are well-known examples of generalized rotations.  A decent
undergrad physics education should include these topics.

The question about generalized rotations and reflections was an open-ended
question.  The questioner didn't give examples, because the whole point of
the question was to ask if there were examples.  Now perhaps some people
don't like open-ended questions -- but they should just say so, and not
pretend that the question didn't use the right words.

Also note that asking open-ended questions is characteristic of the finest
scientific minds.  IMHO this particular open-ended question was the
classiest question on phys-l all year.