Re: Diffraction

[Cliff Parker <cparker@EMPOWERING.COM>]

Leigh Palmer wrote:

> I have the radical opinion that an explanation of the effects
> should not be attempted until it can be approached with appropriate
> mathematics, and that is beyond high school in most cases. The
> students should still be introduced to the phenomena, but it should
> not be necessary to "explain" them in some lame fashion crippled by
> the lack of the right tools.

Convince me.  How will the ideas of wavefronts composed of infinite numbers
of point sources interfering with each other both constructively and
destructively, and the effect on such interference's as these wavefronts
passes through slits going to harm my students?  Two slit diffraction of
light is one of my, and my students, favorite topics of contemplation.  It
seems to me that not a great deal of mathematics is required to understand
that waves will superimpose onto each other and constructively and
destructively interfere with each other given differing path lengths.  How
can I get students to appreciate the dual nature of light without some
understanding of what is happening in diffraction and the fact that this
phenomenon is unique to waves?  Should I teach such a wondrous concept in
the same way that scientific method is too often introduced, as a set of
facts to be remembered but not comprehended?  Too many students leave high
school physics classes knowing that light behaves as a wave and a particle
but not understanding or even considering that such a thing is absolutely
ridiculous.  What good is it to even introduce diffraction (or any other
physical phenomenon) if no explanation is to be offered?

Cliff Parker