coupling constants

The funny thing is I thought I was a good teacher. 

 

First year graduate students are required to spend part of their time teaching.  I drew a two of lab sections of Physics 103/104 -  Physics for the Biological Sciences or, more popularly, physics for pre-meds.  Each lab section had about thirty students and consisted of experiments, quizzes and reviews for tests along with office hours.   I spent quite a bit of time preparing for the classes and the students seemed friendly and interested.  The problem was I didn't appreciate what the students were after.

 

At the time the grade in a physics class was one of the gating factors for admission to medical or dental school and almost as important for nursing school.  My students were strongly motivated to make me feel happy with them as I was a third of their grade.   As long as the labs were done properly I had a lot of freedom and focused on what I thought was important in an introductory course.  

 

That's where it came off the rails. 

 

An undergrad physics degree is partly an introduction to physics at two levels and partly mathematical methods.  You think you're learning physics, but mostly it's problem solving technique and some basic important physics.  There's no sense of the beauty of the frontier.  I find math beautiful, so I was naively happy. Physics has a different way of looking at the world and slowly you begin to adopt that way of thinking.  You're rewiring your brain.  Few know enough to start doing the real thing until the about the second year of grad school. Even then it isn't pretty.   I was trying to teach those poor students what I thought was neat - some math techniques to solve the problems they'd have on their tests.  Fortunately Janos, the professor in charge, beautifully tied the text with real world medical issues and techniques.  He would bring in guest professors from the medical school and he was learning a bit of what they did along the way.  But there was only so much he could do.  As the lab courses were taking place he couldn't teach his grad students how to teach.

 

It took a few years until I realized how beautiful physics, not just the math behind it, really was. About that time I had my second major teaching failure.  I couldn't save myself, but at least I realized I was failing.

 

My advisor required his thesis students to present their work to a class of high school physics students - about the level of an AP high school class.  My thesis was on semileptonic charm production when you slam pions into protons.  You know those examination dreams where you find there's a final in a class you thought you had dropped?  It was worse than that - much worse as I wasn't able to wake up in a sweat.    The next time the class met Paul came in.  In fifteen minutes he gave a beautifully simple and just-correct-enough lecture explaining my work.   The difference was he was a much better physicist and knew the material deeply enough to know what was important and what wasn't at the level of a high school student.  He recognized what could be done with their background.  Anything else and they'd be lost.  I was awestruck.  Later he told me if you're really good, you can do it with eighth graders. 

 

Since then the quality of student teaching has improved.  Stony Brook now requires a course on teaching and physics grad students take Alan Alda's course on science communication. Many of the non-major science courses are more finely tuned to various majors.  I suspect the deepest look at what physics really is would be in one of the history of science or philosophy of science courses.  These things were foreign to me at the time.

 

Wth time I hope I've improved a bit.  It's still difficult finding the right level.  It works best when you're walking with a friend and they know something much more deeply than you and a conversation takes place.  Speaking to a mixed group is more challenging, but perhaps I make myself less of a fool now.  I sometimes worry about this blog and have adopted the approach of treating it like I was talking to a friend.  The problem is it's too one-way, but it is what it is. 

 

Expertise isn't enough.  I was thinking about one of you - an Olympian and an expert in her sport with physical and mental gives along with an enormous amount of hard work.  Is this the right person to teach a beginner in the sport?  Would the best mathematician be the right person to teach a calculus class?  I think the answer is a qualified maybe.  If they've given the thought on how to pull from their depth of experience precisely the right thing for whoever they're trying to teach.   And that brings me to the idea of coupling constants.

 

In physics some of the forces interact in a somewhat similar fashion.  So much so that these forces unify under certain conditions.  Electricity and magnetism are more properly thought as a single force - electromagnetism.  Electromagnetism and the weak interaction can unify and the result can unify with the strong interaction.  This unification is know as the Standard Model in particle physics. Each of the components has something known as a coupling constant that tells you the relative strength of the interactions you're working with.   In teaching the trick is to find the right interaction.  If methods are similar you might even find a coupling constant lurking.  

 

Some people do this brilliantly and in a variety of fields. Carl Zimmer in biology - where I first learned girls are neurologically better predisposed to creative thinking.   The mathematician Steven Strogatz in his book Infinite Powers - a sort of introduction to calculus for people who think they're afraid of math or who took it a long time ago and have forgotten most of what they've learned. Writing a book like this is much more difficult than a technical paper.  You can't have jargon and you need to find ways to connect.  Steven connects.  

 

The other recommedation is for people who can remember their calculus, but are hazy on differential equations.  Differential equations and their partial differential equation relatives are everywhere.  Few things in the technical world can be understood without them.   But solving anything but very easy examples can be hard and a math student can quickly find themselves in the weeds learning odd techniques.  Here Grant Sanderson avoids most of the math and gets to the core of what a simple ordinary differential equation is using a simple pendulum as an example.  It's very beautiful, but skip it if you aren't comfortable with calculus.  This is the level of clarity that an expert can bring to bear.

 

Comments

[Jheri]

You’re the best astronomy teacher I know.