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The Coming Revolution in Physics Education

By David Goodstein

David Goodstein

This essay will end on an optimistic note, but first, the bad news. Let me be blunt. The profession of teaching physics at the college level in America today has only two purposes. One is to produce physicists, and the other is to act as a gatekeeper, keeping the unworthy out of certain other professions such as medicine and engineering. We will always need physicists, but not very many of them. And, indeed, the number of physics majors in colleges all across the country today is said to be at its lowest point since Sputnik, more than forty years ago. Our other role, as gatekeeper, is the dark side of our profession, and it is, frankly, unworthy of us. The simple fact is, if teaching physics were a business, we would be filing for bankruptcy.

Of course, those of us who teach in universities have another educational role, mentoring our graduate students. Here the situation seems profoundly different. The American PhD is the only part of our entire system of education that the rest of the world admires. Yet this role too has its dark side. On the average, each professor in an American university turns out about 15 PhD's in the course of a career. In a steady-state world of science (the best we can hope for at any time in the foreseeable future), each professor need produce only one professor for the next generation. If each of those 15 PhD's want to become professors and turn out 15 more PhD's, it's easy to see why physics has become a profession of widespread frustrated expectations. And, since the undergraduate physics major is largely perceived as preparation for graduate school, it's also easy to see why there are so few undergraduate physics majors. Let's face it: the system is broken.

All right. Let us, for just a moment, pretend that our profession is a business, and take stock of our situation. Our production line is obsolete, and there is little demand for our product. What can we do about it?

The first step is to turn the problem around and ask, do we have any valuable assets that might be worth saving?

You bet we do! What we have is nothing less than the wisdom of the ages. It is that vast body of knowledge, the central triumph of human intelligence, our victory over mystery and ignorance; and to go with it we have the methods of inquiry and analysis that have produced that body of knowledge. Our assets, in fact, are so valuable that we have a solemn duty not to let our profession go down the drain.

The purpose of teaching physics should not be merely to clone ourselves and keep a few poor souls out of medical school. A solid education in physics is the best conceivable preparation for the lifetime of rapid technological change that our young people face. The undergraduate physics major should be the liberal arts education of the twenty-first century! Every physics department in the country ought to inscribe that motto on its walls and march under that banner. But to make that motto into a reality would take nothing less than a revolution in the way we do our jobs.

Everything about the way we teach physics is useless for the purpose I have in mind. The methods, the textbooks, the language we use, all of it is designed more to get rid of the unworthy than to throw open the doors. What we need most of all is to change the mindset that says that real education takes people like we once were, and turns them into people just like us.

I suspect that most of us knew at a very early age that we were destined for some sort of technical career. We were different from other children. We had more facility with numbers, and perhaps less with other graces, than our peers. The education system somehow discovered us and channeled us into the physics apprenticeship, or maybe I should say the rites of passage that qualified us to be the keepers of the flame, subjecting our students to the same arduous rituals that we had passed, to assure that the next generation of us would be as pure and noble as we are.

Throughout most of our history that system worked brilliantly. The first American PhD in physics was granted after the Civil War, around 1870. By the turn of the century we were producing about 10 physics PhD's per year, by the 1930's, 100 per year, and by 1970, 1000 per year. During that century of exponential growth the absolute numbers were small, and only the chosen needed to know anything about physics. Then, around 1970, the crunch occurred. Exponential growth stopped abruptly. We in the universities soldiered on, producing our 15 PhD's and pretending nothing had changed. To be sure, the best American students were no longer going to graduate school, so we replaced them with foreign students, and since our graduates could no longer find jobs so easily, we started hiring more postdocs. Still, at least until the end of the Cold War, we could hang on and wait for the good times of exponential growth to return. We would have been better off waiting for Godot.

To many astute observers, the end of the Cold War, welcome as it was, did not augur well for physics. The unspoken reason why the government supported research in physics had vanished. Many of the National Laboratories had lost their missions. The country was 5 trillion dollars in debt, and scientific research was among the few discretionary items in the budget available for cutting. The situation looked grim.

Then something quite unexpected happened. The country entered an unprecedented period of sustained prosperity. When we looked around to see why we were doing so well, we discovered that we were enjoying the technological fruits of all those years of research that we thought we were doing in support of the Cold War. It was realized, and not only by us physicists, that research is an investment that pays handsomely. Suddenly, physics has a brilliant future again.

Unfortunately though, those of us who teach physics are still living in the past.

Is it conceivable that physics education could be restructured to serve purposes beyond choosing the elect and discarding the rest? The obstacles are immense. We are part of the problem, but we are not the whole problem. It seems to me that the problem has three tightly linked components: societal, educational and pedagogical.

The societal part has mostly to do with one's expectations. We physicists have gained a pretty good understanding of how the world works. Imagine a society in which it is routinely expected that every person in every serious profession shares that knowledge, at least in reasonable measure. Could such a thing happen in America, where nearly everyone (two-thirds of all high school graduates) goes to college and is therefore "educated?" I don't know the answer to that, but if the purpose of education is to render our citizens capable of coping with an increasingly complex technological world, something like it may just become necessary.

For the educational part, picture a world in which every high school teacher (not just physics teachers) commands the pay and professional status that would justify a doctoral-level education in whatever subject they teach. Approximately that was true in large part in Europe before World War II, but then far fewer people got as far as the equivalent of high school. Could it happen here? Maybe not everywhere and for everyone, but that's the road we have to go down. If that were true, then the need to provide those teachers would utterly transform university education at both the undergraduate and the graduate level. Let me be very clear: I am not talking about merely plunking today's excess PhD's into high school classes. What I am imagining instead is a truly profound societal transformation.

Finally, we come to the pedagogical part. Is it possible to teach physics to those who weren't born to it? There has been much research, over the past couple of decades, into physics pedagogy, much of it directed at overcoming the obstacles to turning people who are not like us into people who are like us, that is to say, into proficient solvers of physics problems. That, I suspect, is the wrong approach. What we need to do instead is to figure out ways to show them the high ground and to teach them a few of our more useful tricks, without the slightest intention of turning them into physics foot-soldiers.

Just a few years ago, the computer was a device used by nobody but the likes of us. Then the graphical user interface (GUI) was developed and in no time, tens of millions of people were using computers. The GUI makes the computer less efficient, less flexible, less suitable for real, hard-core professionals, but it makes the computer available to nearly everybody. What physics needs is something that plays the role that the GUI plays for computers.

That does not mean dumbing physics down. In the 1980's, I directed the production of a television series called The Mechanical Universe, that was intended to be the basis of a physics course, with calculus, for nearly everyone. The idea was that we could help teachers overcome the barriers by giving them real physics, in a rich historical context, with beautiful images and terrific computer animation to show their students. There was considerable skepticism that this could be done, so a test was arranged, in which the material was taught to non-physics majors at a liberal arts college. It turned out that the students had no trouble at all with the derivatives and integrals that we taught them how to do. In fact, they quite liked our little mathematical tricks. The experiment failed however, because, although we assumed we would have to teach them calculus, we also assumed, wrongly, that they had learned some trigonometry in high school. Of course, that problem might get solved if we were to undergo the societal transformation I've tried to outline.

We physicists cannot produce that transformation all by ourselves. But we are in a better position than anyone else to take the first few steps. So here is my challenge to us: Let us devise ways to teach physics that will make the subject so vital and appealing that it will be unthinkable for any educated person in the twenty-first century not to have mastered its elements. If we can manage that, it's just possible that the rest of that transformation might follow.

David Goodstein is the Frank J. Gilloon Distinguished Teaching and Service Professor and Vice Provost at the California Institute of Technology.