Phys 87: Thinking Like a Physicist

Meets Thu. 2–2:50 PM in SERF 329 Fall quarter, 2018 (SERF is east of and adjacent to Price Center)

Assignment Completion

Office Hours

Tuesday 12:30–1:30 PM and Friday 10–11 AM: in SERF 336

Course Requirements

In order to receive a P (pass) in Phys 87, you must:

The Goal

This Freshman Seminar is meant to free the minds of our students so that they approach problems with flexibility, intuition, and quantitative estimates. You think that's π you're smelling? It is also meant to provide a mental framework that makes the material learned in future classes more tractable and permanent, by facilitating contextual links.

The Symptom

Students in physics classes often have problems transitioning from lower division courses into upper division courses. Many reasons contribute, but one observation is that students have developed a habit of solving problems by pattern-matching. This can come in the form of equation-hunting or relying on exposure to essentially identical problems from the past.

Human beings are powerfully adept at pattern recognition, and this versatile tool can get us rather far—all the way to upper-division physics. At this point, concepts begin to rule, and students must have a well-stocked toolbox of mathematical techniques at the ready—and know which tools to grab for the problem at hand. Sure, identifying relevant concepts and applicable tools also constitutes a type of pattern matching, but at a higher, more flexible level.

A related problem is that material (e.g., tools, concepts) presented in classes does not end up in long-term storage in students' brains. This may be due to insufficient contextual ties, so that information ends up in a jumbled pile rather than in neatly organized shelves cross-referenced by real-world connections and relevance. It becomes much harder to access and utilize such information if it's in some poorly-exercised junk heap.

Observations

Examples illustrating some of the above points: not knowing whether to multiply or divide by 2π when converting between Hz and radians per second indicates not sufficiently connecting the concept that a circle has 2π radians in it, and Hz is full-cycles per second. Students might not recognize when some math tool from past classes (quadratic formula, integration by parts, etc.) is appropriate for the task at hand. Some students do not hesitate to integrate x⋅dx, but get stuck if it's the integral of y⋅dy—indicating a regrettable rigidity and misdirected contextualization of symbols.

Causes

One may only speculate, but here are some thoughts:

The Cure

So let's try re-programming the way students approach problems before reaching the upper-division whiplash moment. That's what this Freshman Seminar aims to do. No guarantees that this will be successful, but let's try building comfort and versatility in thinking about problems so that students have better intuition and alternate ways to sanity-check their answers. Among the approaches, we will:

Some Philosophy

Famous physicists like Fermi and Feynman frequently forged formidable feats 'festimation. Less alliteratively, good physicists tend to have well-developed estimation abilities. Seldom are these skills learned in classes, but "learned on the mean streets," as my colleague George Fuller puts it. Maybe it's a selection effect: those who are good at estimation are more likely to succeed in physics/science.

For me personally, I learned at least as much in my explorations outside of class as I did in the formal classroom. I almost always had some problem I was chewing on, and my eagerness to understand and make progress drove new discovery. What's more, because I had problems in mind (many of which I got stuck trying to solve), when new concepts and tools became available in the classroom, I would think, "Aha! That's the piece I've been waiting for!" and I could return to the problem and do it less clumsily than before. By having context in mind already, I had carved out space waiting to be filled by classes. By exploring the problem before and after new techniques came along, I owned the material. It was personal. It meant something to me.

Examples of problems that occupied me during high school and college appear in the list below (not chronological). I'm sure I am forgetting numerous lesser problems, but these are the ones that stand out in memory. And yes, my tendency to actually carry out these schemes brands me as an experimentalist. But just because kid-me did some stupid things does not mean that adult-me condones these activities!

A Word on Emulation

The lesson should not be to copy what I did. I'm not trying to say that I'm a rock star, but will point out that emulating a rock star's visible behavior is not effective (and will probably land you in jail!). Countless hours practicing and honing the basic skills is where it's at (which is utterly boring to most people). Concert pianists spent years perfecting excruciatingly uninteresting scales before spinning off masterpiece performances. Emulation is not in itself a likely path to success. Rather, find your own interests and ask your own questions. Let your curiosity guide you. Plunge in to solve problems or go as far as you can while you wait on pieces to fall in place. Don't be afraid to explore. It's stumbling into the dark that lets you build a picture of what you can't see by staring into that darkness.

Your Personal Question Bank

Recognizing that questions were an important part of my learning, and allowed me to build instant contextual links to new material, I want to help you do the same. Let's think of your brain as a warehouse where the college experience will bring daily deliveries of new material. Don't let it all pile up on the floor in an unordered mess. Let's make some shelf space with labels already in place. For me, this is what having questions/curiosity did.

So each week, I will have each student turn in a question (part of basis for grade). The question should be genuine and personal: something you really care about. I will select among these questions to guide class discussion, in which we use tools of physics to make progress in answering the question (maybe sometimes only partially or tangentially). By sharing questions, you might adopt others' questions for yourself as well. This just means more shelf space for future classes, where you're waiting for the day when a relevant topic is finally covered in a class. Now you know where to put it: fills a ready-made void in your brain.

The questions are not meant to impress me or other students: don't waste time thinking in this direction. I'll respond best to questions that ring true in terms of some personal connection/interest, and less so to deep philosophical questions. And more importantly, they'll serve you better in the future if they have genuine personal meaning. The questions most likely to get attention in class are those that involve some quantitative answer/approach.

Metacognition

While it might sound like psycho-babble, metacognition is thinking about thinking. It's reflecting on what goes on in your brain when solving problems. It's recognizing when distracting thoughts are getting in the way (why can't I do this; maybe I should check for messages). It's tracking the wrong and right turns and learning effective mental strategies. In my role as instructor, I'll try to unpack thought processes in my own head so you can see some of the wrong and right turns and use that as a model. Whether or not it's useful, it is through metacognition that I have come to think that a framework of questions can pre-load the brain with order/structure making learning more meaningful and permanent. At the end of the day, learning involves the physical process of rearranging neural connections in your brains. So I'm trying to operate as a brain mechanic, in some sense. That's why it makes sense to think about how to facilitate this mental development—and that's metacognition.

Possible Topics

All the stuff above may give a false sense of what the course will be about. It won't be a course in cognitive science or learning. It will be physics-based, focusing on fun, relevant problems as a way to expose you to how physicists think about and approach problems. In the course of tackling the questions posed to the class, we are likely to cover topics from the following list: