Quantum Mechanics
as a General Audience Course

This page written by Dan Styer, Oberlin College Physics Department;
http://www.oberlin.edu/physics/dstyer/TeachQM/QMforGA.html;
last updated 25 January 2000.

Contents

• Abstract
• Initial goals
• Course materials
• Evaluation
• Conclusion

My thanks to the Sloan Foundation, which supported early stages of the course development described here.

In 1989, I began teaching a course on "The Strange World of Quantum Mechanics" to general audience students at Oberlin College. My goals in developing this course were:

• I wanted to learn something myself.
  I had been involved with quantum mechanics (through reading, studying, researching, or teaching) since I was a teenager, yet I found it impossible to answer simple questions from my friends. I wanted, as much as is possible, to understand as well as to calculate.

• I wanted students to see the wonder, beauty, and surprise of our own world.
  Although the word "mundane" derives from "of the world", I wanted to show that our world is not mundane.

• The course would have problem sets.
  It's easy to hide behind vague generalities. (Congress does it all the time.) I wanted my students to get the intimate involvement with nature that comes only from rolling up your sleeves and mucking about in the details.

• The course would not be story telling.
  I wanted to teach a physics course, not a history of physics course. As a teen, I had read popular books on quantum mechanics that told biography when the physics got hard, and physics when the biography got hard. I was left with the impression that the most important aspect of quantum mechanics was the horseshoe that Niels Bohr nailed over the doorway of his summer cottage. Story telling has an important role to play, but I didn't want my course to play this role.

In short, I wanted to distill the essence of quantum mechanics into a rigorous, though non-technical, course. I did not want a watered-down, superficial, "gee-whiz" course. This is why I used the term "course for a general audience" rather than "course for non-science students". My aim was for a course that, while populated mostly by students not majoring in a science, would be both informative and challenging even to the rare physics major who took it.

I knew that this was an ambitious goal and I thought it most likely that I would fail.

It was rocky going the first few years. Much of the published material at this level was (and is) aimed at those who wanted to debate overarching philosophical principals of various interpretations without first digging into the specifics of what they were interpreting. There was no reliable source for thoughtful, penetrating exercises.

I used the following two sources to good effect:

• Richard P. Feynman, QED: The Strange Theory of Light and Matter (Princeton University Press, Princeton, New Jersey, 1985).
• N.D. Mermin, "Is the moon there when nobody looks? Reality and the quantum theory", Physics Today, 38(4) (April 1985) 38-47.

• P.G. Kwiat and L. Hardy, "The mystery of the quantum cakes", American Journal of Physics, 68 (2000) 33-36.

However, in the end I had to write my own book, which was published last month:

• Daniel F. Styer, The Strange World of Quantum Mechanics (Cambridge University Press, Cambridge, UK, 2000).

[Mine is not the only possible rigorous but non-technical approach to quantum mechanics. You could use polarized light or continuum particle motion as your canonical system. You could put more emphasis on quantization and less on entanglement and interference. You could tell the story along more historical lines, but let me warn you that, in this last case, you will have a hard time telling the story without mentioning energy, and I have found this to be a mistake in teaching physics to general-audience students: first, these students do not know what a physicist means by "energy", and, second, they think that they do.]

• I wanted to learn something myself.
  I certainly did. I don't claim to understand quantum mechanics (to do so would be a sign of mental instability) but I certainly understand it better than I did before. In particular, quantum mechanics used to all just seem strange to me. Now I have a good conceptual map of the various types of strangeness, of their logical interconnections, and of how each type is forced upon us by experiment.

• I wanted students to see the wonder, beauty, and surprise of our own world.
  Some students share my enthusiasm. Others are just too sophisticated.

• The course would have problem sets.
  I am particularly proud of problems 9.3 (interference) and 14.1 (Bragg diffraction) in the book, although there's still a lot to be done in this arena. The problems develop the students' general problem-solving skills and increase their respect for logic as a probe into the unknown -- a probe that remains powerful even when common sense fails.

• The course would not be story telling.
  My biggest surprise in developing the course: I have found story telling to be a powerful teaching tool. I quote poetry to good effect. The body of the course doesn't mention history, but I conclude with a fascinating historical survey which serves to summarize and tie together the whole course.

Welcome.

What has been done -- by myself and by others -- is just a start. There are many courses and a galaxy of approaches to teaching special relativity to a general audience in a rigorous yet non-technical manner. The same could be true for quantum mechanics. This work is nationally important and personally rewarding. I invite you to join in.