Thursday, January 1, 2015

The Character of Physical Law: Feynman helps me plan my next course


Happy New Year!

This week I have been reading Richard Feynman’s The Character of Physical Law. The book is a compilation of the Messenger Lectures given by Feynman at Cornell University in 1964. Feynman started his academic career as a professor at Cornell, and after five years there he moved to (my alma mater) Caltech. He is reknown for being both an outstanding teacher and scientist. His lectures on physics are outstanding for their clarity.

Before delivering his first Messenger Lecture, Feynman was introduced by Dale Corson, provost at Cornell. Besides the usual laudatory remarks on Feynman’s achievements and some historical tidbits, Corson added that “in the preface of the published lectures there is a picture of Feynman performing happily on the bongo drums”. Feynman is a multi-talented colorful character and his reminiscing is collected in a delightful series of essays published as Surely You’re Joking, Mr. Feynman! Thus when Feynman was introduced to a scientific audience, reference was often made to his other pursuits and interests outside of physics.

After Corson’s introduction, Feynman began his first lecture with the following bit of wit. “It is odd, but on the infrequent occasions when I have been called upon in a formal place to play the bongo drums, the introducer never seems to find it necessary to mention that I also do theoretical physics. I believe that is probably because we respect the arts more than the sciences.”

In my experience, I think it is not so much respect for the arts, but rather fear of the sciences and its inaccessibility. When I meet someone new, inevitably the “What do you do?” question comes up. Although I usually tell folks that I “teach college students”, the follow-up question is “What do you teach?” The most common responses to the revelation that I am a chemist is “Oh, that was my worst subject in school” or “Wow, you must be really smart” or “I once took a [science/math] class and I don’t think I understood anything”. Scientists and teachers share part of this blame. Since I count myself in both groups, I need to do my part in dispelling the notion that science is inaccessibly difficult, or worse, dreadfully boring in its esotericism.

As I have been planning the revamping of my General Chemistry class next semester (see the open letter I wrote to my students), I have been thinking about the broad sweep I would like to take. I am also trying to work out some of the nitty-gritty details for the first several weeks of class. I usually don’t bring work home with me on weekends, evenings or holidays. But this time around, for the December holidays, I brought back my previous lecture notes, assignments and exams, and the current textbook we are using. My plan was to list the specific content learning goals of the course, and then figure out a way to wrap things together so I can motivate the students appropriately. I would like them to find this class interesting, engaging and challenging, and that they would be motivated to do the appropriate pre and post class assignments.

I have not gotten around to writing out anything other than these blogs (as I’m still on holiday) but the thinking time has been useful. Reading broadly over the holidays has also helped to shape how I would like the class theme to unfold. Since the second semester of General Chemistry is mainly about thermodynamics and equilibria (with some kinetics, electrochemistry and colligative properties thrown into the mix), I think I will wrap my class around the broad theme of Energy.

My plan is to start out with our sun as the energy source sustaining the bioenergetics and activities of living creatures here on Earth. We might lead off with nuclear energy (because nuclear chemistry gets short shrift in the first semester – we cover radioactivity and balancing nuclear reactions but don’t have time to go into the detailed energy considerations).  Then we will pick up on thermochemistry before moving on to electrochemistry. The role of catalysts and materials in the harnessing and storage of energy (while battling entropy) both in man-made devices and in living cells will hopefully feature prominently.

I might be over-ambitious but I would like students to get a taste of two broad areas: (1) the “energy issues in today’s technological society” and, (2) the riddle of how chemical energy was harnessed into biological systems in the origin of life. (The latter was discussed briefly in my post last week.) This way I have some open-ended speculative projects the students can work on wherein they will learn a bunch of chemistry along the way, but will also get a taste of what complex problems look like. The goal isn’t to “solve” the complex problems but rather to learn how to approach them, making use of what you know, learning some new things, and figuring out what else you will need to learn (that you won’t have time to cover during the semester). The projects should also be collaborative (no one person can figure this out) and thus provide good training for the students to go out and solve real-world complex problems in teams.

Where does Feynman’s book come in? Energy, it turns out, is a very slippery topic for students. It is not easy to grasp and I’m pretty sure my students (even though they’ve had first semester General Chemistry) are still rather fuzzy on the concept. I thought Feynman did a great job introducing Conservation Laws in Chapter 3 of The Character of Physical Law. In the letter to my students I told them that I would like to expose them to outside reading material instead of slavishly following the textbook. I’m therefore thinking of having them read some selections from this chapter on Energy Conservation as their first pre-class assignment. Feynman writes lucidly and I think it would be good for students to be exposed to different teachers, many much better than me.

Towards the end of Chapter 5 (on entropy and irreversibility), Feynman makes a claim in support the importance of having an interdisciplinary “liberal arts” outlook in learning. Or at least he seems to be trying to build a bridge between Snow’s two cultures. In contrasting “humanities” level ideas such as evil, beauty, and hope, with fundamental low-level “basic science” level ideas such as the fundamental laws of physics, Feynman writes: “To get a deep understanding of the world with only [one level] alone is a mistake. It is not sensible for the ones who specialize at one end, and the ones who specialize at the other end, to have such disregard for each other.” In fact it is the many “in between, connecting one step to another, … working at the ends and working in the middle [to gradually understand] this tremendous world of interconnected hierarchies.”

I hope that students in my class don’t just learn fundamental concepts of chemistry, but because they have opted to have a liberal arts education, that they will see the interconnections between hierarchies in my class and in all their other classes.

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