Old Physics Young Biology

From Physics

It all started with Alex (Small) coming into my office and asking me about interactive teaching methods, FCI learning gains, etc. Since Alex S. is a theoretical biophysicist, he knows about biology curriculum. In introductory physics what we teach is obviously at least 100-year old physics. In biology, however, what they teach is usually mostly new stuff. Therefore, it might be likely that most innovative minds will choose biology, not physics, as they are not able to see the current-day physics activities.

I kindly disagree with the argument. If we go back a century, and look at the physics curriculum in early 20th century, I think we would find that physics taught those days was about a decade old, similar to what we have for biology now. In essence, the current status is a result of how much we know in physics and biology.

Secondly, 100-year old physics is not useless. We still use it to solve many problems. With 100-year old biology you cannot do anything. Many stuff in biology are being learned anew, so the old biology is useless.

Third, physics content being 100-years old does not mean that people know it already. Unfortunately, many people have ideas as old as 2000 years with respect to the phenomena. Hastenes at Arizona State, I remember, found that many students think of motion like Aristo even after completing a physics course. Biology, on the other hand, had been known as memorizing certain parts, components, cell types, organels, processes. The new biology with all biophysics and biochem makes it more like real.

With all these said, I believe, if one can teach physics with applications, examples, and problems in current-day research it will certainly be more effective in convincing innovative people to choose physics as a career.

Alex Small Replies:

Everything that Ertan says is sensible. 100 year old physics is indeed useful, and much of it is in fact necessary for learning newer physics. Second, our conservatism reflects a valuable style in which we focus on the problems that we can approach from a fundamental angle with precise and powerful methods. It would be a shame to lose that. Third, the introductory physics class is of course subject to all sorts of institutional constraints, so any conjectures that I offer regarding modernization are intellectual exercises, not proposals for declaring war on client departments.

Still, as a scientist something in me recoils from devoting all of our attention to 100 year old physics. The frontier of science is always more exciting than the settled issues, and we all go into science because we want to learn something new. At its root, science is about a method for acquiring new knowledge; it is not a body of old knowledge. And we are proudest when our students go out and do something new in the world, not when they get 100% on a test covering well-known topics.

Moreover, while the standard math-based physics courses are deeply conservative, many other service courses (both here and at other institutions) go into more contemporary issues. "Physics for Poets" intro classes often devote significant attention to frontier topics because the students aren't trying to master 100 year old physics as a prerequisite for something else. GE courses like "Energy and Society" and even "The Universe in 10 Weeks" include significant amounts of contemporary, cutting edge issues. And when I taught an optics course for photographers, I was able to discuss new imaging technologies. It's interesting that when students are able to take a class as an elective rather than as a prerequisite, and when faculty are freed from the constraints of service courses, the most successful offerings deal with cutting-edge topics. Economists would call this "revealed preference."

Surely there must be ways to incorporate new physics into introductory courses. If not as a core topic, perhaps as a context for problems. Just as much of the new stuff in science requires the old stuff to be understood, at the same time the newer contexts and topics can often be simplified to the point where they are treated with more basic physics. I (like everyone else) do a bit of this, and most textbooks paint a thin veneer of this into the occasional section at the end of a chapter. However, it's a thin veneer, and the vast majority of homework problems are set (perhaps out of necessity) in less exciting contexts. To venture beyond this in a non-trivial manner, making it a consistent theme rather than an occasional aside, really requires new instructional materials, unfortunately.

And even if this is impossible at the introductory level (for practical as well as pedagogical reasons), surely there is some flexibility at the upper division level.

But I come here not just to bury physics, but to praise biology as well. Friends, colleagues, administrators, lend me your ears:

What impresses me about biologists is their adaptability. One of the most universal paradigms in biology is evolution, and they exemplify it. A technique can go from novelty to standard tool in less than a decade. Any experimental physics technique developed a decade ago is at best a special topic given a paragraph at the end of a chapter in a physics book, but in a biology book that data will might be shown repeatedly throughout the book. Data from the Human Genome Project is in the 2002 edition of "Molecular Biology of the Cell." Moreover, their idea of good teaching practice is to read original literature (maybe not as freshmen, but certainly in upper division courses) and discuss it. The fact that they write papers that undergraduates can understand speaks highly of them as a profession. Also, their use of visualization tools and software impresses me. Perhaps it's just that I'm not a visual person, so I regard anything graphical as a pain to prepare, but I'm always amazed by the animations and structures that they present at conferences.

Perhaps they adapt rapidly out of necessity, while we adapt slowly to preserve skills that have served us well. But their adaptability scares me, a bit. For now, biophysics is in a growth stage, so it might seem silly for a physicist to fear them when we're eating into their grant money. However, their adaptability might enable them to produce a generation of truly cross-trained students who can produce a different curriculum. In that situation, we might return to the role of service providers, teaching only those courses that they don't want to teach on their own. As attractive as it sounds to have a market for our upper division courses, if we cannot adapt and approach them as equals we will not be partners in that endeavor.

But, a word of hope for physicists: Despite the recent vintage of NIH funding for physics departments, biophysics is not young. The Biophysical Society has been around for decades, and many of its oldest members were trained in traditional physics. They went into biophysics, and eventually found that biology and chemistry departments were more hospitable places to work. They developed specialties, and adapted within those specialties and constantly brought in new techniques. However, they lost touch with physics, they failed to take full advantage of the power of theoretical physics (though they have been good at adopting experimental tools and black boxes from computational chemistry), and they worked with a population of students who were more interested in med school than math. In time they lost their physics nature, and their students were more accurately characterized as cell biologists with strong physical chemistry backgrounds. It wasn't until the 1990's, when physics departments re-entered the game, that biophysics really made contact with physics again. (Although it still has a long way to go, judging from the topics that dominate at Biophysical Society meetings. Work that brings a genuine physics flair to a biology problem is still in the minority.)

So perhaps there's hope for them. Perhaps our conservative nature preserves something that is useful for learning new things in other disciplines but cannot thrive in those disciplines.

What is New in Physics?

Most of the stuff is actually not "New Physics", but different applications of relatively "Old Physics". So, we would like to include whatever has been done at research labs, and published recently. This is obviously easier to do in the upper division courses, and GE courses as Alex S. mentions. One good example to this was Robert Hellwarth's lectures at USC. He used to give a class titled "Optical Instruments and Devices", a grad course in EE, every time he taught the content was a bit different. He made us work on Sony's then-new magneto-optic discs.

Let's try to list what you would like to include even in our courses, then we can talk about how this may be done. (Introductory or upper division)

• Photonic Crystals
• High-Q systems (oscillators, sensors)
• Fiber Lasers
• Nanoparticles and their applications (drug delivery)
• Metamaterials, negative refractive index
• Organic solar cells
• Holography
• Surface plasmons
• Biosensors
• Fluid transport in biological systems
• Viscoelastic properties of cells and tissues and implications for pattern formation and development
• Optical imaging below the diffraction limit
• Quantum information (both computation and cryptography, the later of which is seeing commercial implementations)
• Complex fluids (colloids, emulsions, foams, gels): Structure, self assembly, and mechanical response (solid-like on short time scales, liquid-like on long time scales)

New Physics vs. New Science

One could argue that from a fundamental perspective there is very little new physics. We have the fundamental equations of electromagnetism, classical mechanics, statistical mechanics, and quantum mechanics, and everything in the list above is in some sense reducible to those basic phenomena. However, one could also argue that when a system obeying those laws exhibits qualitatively new and surprising phenomena, it is in some sense new physics, or at least new science. For instance, negative index materials can be understood in terms of Maxwell's equations, so in some sense they are an application rather than new physics, but they present new phenomena of interest to physicists.

It comes down to what we consider new physics.