Physics for Future Presidents
Richard A. Muller
[Dr. Muller's book was reviewed in the October 2009 edition of P&S. The course he describes here has developed a reputation as "one of the courses you MUST take at Berkeley" and in 2008 and 2009 was voted "Best Class at Berkeley" in a poll taken by the student newspaper – Ed.]
"Physics for Future Presidents" is the name of a course I have taught at Berkeley for the past ten years, as well as the title of the book derived from the course. I created it when I was asked to teach a "Physics for Poets" course at Berkeley. Many of my students have become government and business leaders, and I have high regard for them. They are smart, effective, and in many ways more productive than the typical physics professor. I became convinced that it was not only vitally important to teach these students some "real physics" but also that it could be done in an effective way. Many important issues have physics or high-tech components: energy and alternative energy, nuclear power and weapons, terrorism and counter-terrorism, health, internet, satellites, global warming, remote sensing, ICBMs and ABMs, DVDs and HDTVs. So many people in our government have a poor grasp of science, and yet if they misjudge the science, they can make a wrong decision. My new approach to teaching physics was inspired by this concern and also by the enormous success at Berkeley of an introductory astronomy course by Alex Filippenko that attracted 800 students compared to the meager 35 who signed up for our "qualitative physics" course. What was the difference? Alex showed me his curriculum, and I was amazed to discover that his course had a huge amount of substance, far more than we had in our qualitative physics course. I realized that the way you get students to take physics is to give them a course where they can come away saying "I have really learned something." In this article I will describe my class and the book with the hope that others may wish to use them as models for course offerings of their own.
Too often in the "Physics for Poets" approach professors assume that students can't learn "real physics." We end up talking down to them, rather than treating them as the future leaders many will become. We hide behind the fog of math: Any time a question is too hard, write an equation on the board. Then say that the reason you can't answer it is that the math is too advanced for the student to understand. That's almost always nonsense. The reason that so many students dislike physics is because we are trying to teach them to become mini-physicists, and you can't accomplish that in one semester. Physics is the liberal arts of high technology. PffP (my abbreviation for the course) is designed to attract students and teach them the physics they need to know to make effective leadership decisions.
Can real physics be taught without math? Yes! Math is a tool for computation, but it is not the essence of physics. We often cajole our advanced students, "Think physics, not math!" You can understand light without knowing Maxwell's equations. If a leader needs a computation, they can always hire a physicist. But the knowledge of physics will help them judge, on their own, if the physicist is right.
An anecdote: the ideal student
To illustrate what a student can learn, I like to cite the example of Liz. A year after she took my class she came to see me, eager to share an experience she had had a few days earlier. Her family had invited a physicist over for dinner. He regaled them with stories of controlled thermonuclear fusion and its great future for the power needs of our country. The family sat in awe as this great man described his work. Liz knew about fusion because we had covered it in our class.
There was a period of quiet admiration at the end. Finally Liz spoke up. "Solar power has a future too," she said.
"Ha!" the physicist laughed. "If you want enough power just for California," he continued, "you'd have to plaster the whole state with solar cells!"
Liz answered right back. "No, you're wrong," she said. "There is a gigawatt in a square kilometer of sunlight, and that's about the same as a nuclear power plant."
Stunned silence from the physicist. Liz said he frowned. Finally he said, "Hmm. Your numbers don't sound wrong. Of course, present solar cells are only 15% efficient… but that's not a huge factor. Hmm. I'll have to check my numbers."
That's what I want my students to be able to do. Liz was able to shut up an arrogant physicist who hadn't done his homework! She knew enough about the subject that she could confidently present her case under duress when confronted by a supposed expert. Her performance is even more impressive when you recognize that solar power is only a tiny part of this course. She remembered the important numbers because she had found them fascinating and important. She hadn't just memorized them, but had thought about them and discussed them with her classmates. They had become part of her, a part she could bring out and use when she needed them, even a year later.
The Class: Advanced Physics
PffP is not watered-down physics. It is advanced physics in the sense that it is the physics that most physics majors learn only after finishing their PhDs. It covers interesting and important topics. Students recognize the value of what they are learning, and are naturally motivated to do well. Rather than keep the students beneath the math glass ceiling, I take them above it. "You don't have the time or the inclination to learn the math," I tell them. "So we'll skip over that part, and get to the important stuff right away."
In fact, a typical physics major, even a typical PhD, does not know the material in my book. He or she often knows little about nuclear power or weapons, optics, fluids, batteries, lasers, IR and UV, x-rays and gamma rays, MRI, CAT, and PET scans. Ask a physics major how a nuclear bomb works and you'll hear what they learned in high school. For that reason we have now opened this course for credit for physics majors at Berkeley. In fact, the physics department at Berkeley now recommends that a potential physicist take my course before beginning their major. This is material that typically is not taught in the other courses, and yet it puts the material of the other courses in context.
I made one major concession to my students. They really do want to learn about relativity and cosmology, subjects superfluous for world leadership but fascinating to thinking people. So I added two chapters at the end. They cover subjects that every educated person should know, but they won't help the President make key decisions.
I have email correspondence with every one of my students. That has gotten a bit difficult as the class has grown to over 500 but I've kept it up. Prior to our first meeting I send all students a message and ask them things such as their name, the most advanced physics they have studied, why they are taking the course, and the subject they are most interested in learning about. From the responses, I've discovered that about half of my students have physics dread. They either hate it because they had a bad experience in high school, or they are simply really afraid of it.
Virtually all of my students –by now eight or nine thousand – lost whatever physics dread they had. Most of them have learned to love physics, and they now know that when they don't understand something, it isn't their fault. They have become the "physics expert" to their friends and family. I tell them that if you learn some of this physics you'll go home and start winning arguments with your parents – over nukes, space, alternative energy, terrorism, global warming. The best way to win an argument is not by having a forceful opinion but by having some knowledge. I tell the students that I don't care if they are anti-nuke or pro-nuke; they are going to learn a lot about nukes – nuclear weapons, nuclear power, nuclear terrorism. My course has developed a reputation as "one of the courses you MUST take at Berkeley". In fact, for the past two years (2008 and 2009) in a poll taken by the student newspaper, my course was voted "Best Class at Berkeley." I get students from every discipline, from English majors to music to pre-law and pre-business. I try very hard to keep my own opinions out of the class.
What do the students find most exciting? They love to learn about energy. What does "energy" really mean? What can "alternative energy" do, and what can't it do? They love learning about radioactivity and nuclear weapons and nuclear everything else. They are fascinated with space: what can we really do in space, what is it valuable for, and what is it not useful for. They love the non-partisan view – the facts – about global warming.
When other faculty look at my curriculum, they are typically amazed that I cover so much. But sometimes when they look closely they are concerned at what I leave out. The concept of "conservation of energy", something all physicists love, is one. I looked at the introductory physics sequence for majors, and discovered that it takes over a year before even math-adept students begin to understand this subtle concept. It is not only hopeless to teach it to non-scientists in one semester, it is counter-productive. The abstract principle of conservation of energy is just not that important for the future president of the United States, who is likely to be much more concerned about the conservation of useful energy.
Here is the quick summary of my approach to PffP; a more complete description is available in the teachers guide to the textbook (available for free to any certified instructor).
1. Immersion. Teach energy not by definition but by examples. This is analogous to learning a foreign language by living in a foreign country.
2. Order of topics. Put most fascinating topics first: energy, satellites, radioactivity, nukes. This motivates and intrigues.
3. Numbers. Work with scientific notation. Math-phobic students are OK with this; it is problem solving with multiple unknowns that frightens them.
4. Understanding. Teach students the relevant science for issues of importance. Enable them to elicit the relevant facts and numbers and concepts when they are needed. Emphasize writing in the exams so that students learn to explain a subject clearly and concisely, with numbers.
5. Respect. Treat the students with the expectation that one of them will someday be a world leader. This is your one chance to teach such a person.
6. Reading and Writing. Liberal arts students love to read. Encourage them read the material over and over, so that lectures do not have to cover everything.
7. Motivation. Emphasize the importance of everything. Pick subjects that stir interest and curiosity.
8. Physics as a Second Language. Teach students to use terms correctly. We are teaching "physics as a second language."
9. Multiple levels. Provide some material for those students want more math. I sometimes take five minutes out of a lecture to do some computations, telling the students that the material will not be on the exam. Nearly all the students end up listening to the math approach without the anxiety of having to master it.
10. Politics. Keep your politics from your students. I am proud that students don't know my personal views. When asked about a controversial subject, I do my best to give both sides.
11. What not to teach: How to solve problems using conservation laws. The "scientific method".
12. Question period. For the first 10 minutes, answer questions on any subject. The goal here is partly to answer questions, but also to show students how I handle things I don't know.
13. Fun. Make sure that students are finding the class material riveting. If they don't, it shows in their expressions, and tells me to change my approach, maybe through different examples. I encourage students to share their knowledge with their friends and relatives.
14. Commencement. The physics that can be learned in one semester is tiny compared to how much the students can learn in a lifetime. I discovered that prior to my class, many students didn't pay attention to tech issues. I assign a weekly reading of articles on science, to get them in the habit of reading these articles.
Text: Physics and Technology for Future Presidents
The book comes in two versions. The popular one, "Physics for Future Presidents," is a paperback that's meant to be a page-turner, to be read by the general public. For a course, students like to have more structure: they want it broken into segments, to have summary sections and problems, questions for further thinking, things they can research on the internet, places where they can get more information, samples of essay questions, multiple-choice questions – the sorts of things that are likely to appear on exams. For that, I've written a hard-back textbook, "Physics and Technology for Future Presidents." The longer title is mostly to distinguish it from the paperback. This textbook contains about twice as much material as the popular version. An accompanying manual for the professor not only has an answer key but relates much of the experience I've had and the lessons I've learned: What kind of homework and quizzes work best? What are the tricks to really appealing to the nervous student? It gives several of the exams I've used in the class. It has plenty of flexibility; there are lots of sections, and most of them can be easily skipped at the discretion of the teacher. Naturally, the course is somewhat cumulative: you have to know about energy before you can discuss nukes or global warming. But if you want to cut out the section on space and satellites, or the one on "invisible light" (IR, UV, x-rays) you can do that with no significant harm.
The ultimate goal is to have both elected and electorate be scientifically literate. I have tried to create a course that does not depend on me or my own personal experiences or style of teaching. The course might be intimidating to a potential professor, since so much of it is unfamiliar. But the material is fun to learn. Much of the material in this course was new to me when I began to put it together. I didn't know the energy density of batteries, or of gasoline. I wasn't particularly familiar with the levels of radioactivity needed to cause cancer, or with the detailed data that is used to support arguments on global warming. Now I know these things. I encourage others to give it a try. It is a lot of fun to teach, and I continue to learn. The students love it, and that makes teaching this course very rewarding. Part of the joy I get in teaching this class comes from just looking at the students: they don't appear stressed out but rather have their eyes wide open, trying to understand this stuff. Part of the joy comes from interacting with students who attend my office hours with their list of questions. They've discovered that they can understand it, and so they really want to.
Richard A. Muller
These contributions haven not been peer-refereed. They represent solely the view(s) of the author(s) and not necessarily the views of APS.