Re: [Phys-l] Physics Grammar

["John Clement" <clement@hal-pc.org>]

The use of terminology can be both underrated and overrated.  I would say
that using the term light with IR or UV is fairly benign wrt student
understanding.  Professionals of course have no difficulty there.  Students
are quite willing to memorize a pat set of classifications without
understanding what they mean, or how the terms relate to the things being
classified.  The term light does emphasize that UV and IR are closely
related to visible light.  So one of the real difficulties is to get
students to understand that the dividing lines are arbitrary and may be
changed so as you go up or down the spectrum just crossing a line does not
produce a dramatic change.  To a certain extent the arguments over whether
to call it light, rays, radiation, or waves is similar to counting the
angels on a pin.  Each word emphasizes characteristics of that part of the
spectrum, and can be useful.

However the use of the words action and reaction can be quite corrosive to
student understanding of NTN3.  They bring up the picture of the motion
rather than the forces.  So why continue to use these terms in textbooks.  A
much better formulation of NTN3 should appeal to the idea of interactions
and emphasize that the 2 equal and opposite forces are due to a single
interaction between 2 different objects, without using the traditional
words.  While I am mentioning this, the usual treatment covers the laws in
the order 1,2,3, but it works better if they are covered 3,2,1.  Tradition
in this case is a poor guide to better understanding.

John M. Clement
Houston, TX

> What risks do I run when I say things like, infra-red light, UV light, X-
> ray light? I haven't said "gamma light" yet, but it isn't out of the
> question.   I've been using these terms for about 5 years.
> I work with kids in grades 9-12.  At the start of my first crack (grade
> 9), many think sound & light are the same type of wave (either both are
> mechanical, or both are EM waves).
> I've been using IR-Light, UV Light etc... and stating that they are the
> same thing, just at frequencies outside of our visible range.
>
> Am I causing any damage here?
>
> I understand that is similar to the question that began this thread.  I
> believe it might be a bit different.  I am not asking if this should
> become standard notation or if we should be saying UV EM light radiation
> waves.  Am I abusing folks in some way?  I don't want somebody claiming I
> am the source of their abuse (dis-abuse?).