Re: Demos, simulations, and activities for Modern Physics

[palmer@sfu.ca (Leigh Palmer)]

Dennis Krause asked:

>        I would like to enlist the help of all those on this list for
> suggestions on how to make the topics of modern physics more real to my
> students.  What demonstrations, computer simulations, and/or other
> activities have you found useful in illustrating (in a fun and stimulating
> way!) the far-out concepts of relativity (special and general) and quantum
> mechanics to non-science students?

and he was rewarded with computer simulations. Will these really help any
students (especially humanities students) appreciate the reality of the
phenomena under discussion? I don't think they will; they certainly would
not have convinced me.

Of course demonstrations are difficult to perform in this area, but the
few that can be done should be done. Certainly it is not too difficult to
produce a radioactive source, a clicking radiation survey meter, and for
the brave, even an electroscope to make the point. It can sure add sex to
a lecture on how one determines the age of the Earth. It would also be a
good time to tell them how a smoke detector works; they want to know.

How about something as simple as the atomic model of matter? Would it be
difficult to cleave a rocksalt crystal on the overhead projector? Few of
your students will have done that themselves.

Single, double, and triple slit diffraction can be exhibited using a
laser, followed by the diffraction grating (disperse a line of light from
the overhead projector) and laser diffraction from a grid or a piece of
suitable woven cloth. This can be followed by an electron diffraction
demonstration if you have the apparatus, or by showing the students the
patterns at least.

While it may be impossible to demonstrate the quantization of charge to a
class, it is possible to show them the apparatus and to get a TV view of
what happens when one switches the electric field.

These are a few of the *demonstrations* of the phenomena of "modern
physics" that can be done for a class. Instruments are required for many
of them, but the students should be aware that science is the process by
which we extend our senses through the use of instruments. They will
accept Geiger counters (even more readily electroscopes which can also
be discharged by holding a flame nearby) if you tell them how they work.
A computer simulation of barrier penetration can only fascinate a very
well prepared mind; that's why we think simulations are so neat! It is
of little value when shown to students who are incapable of doing
algebra, let alone understanding Schr=F6dinger's equation.

They want to know. Satisfy that desire.

Leigh