"What is Teaching Physics" and Other Pre-amble

In this post: General musing on physics teaching and then some gritty details about my lesson plans. Kind of like those boring college classes where the professor reads the syllabus even though the last half of it is exactly the same for every other course you've ever taken .

What is "teaching physics"?

Now that I've decided to try to teach my mom physics (and she has decided to let me), I have to determine what exactly I mean by "teaching physics." What do I hope to accomplish by the end of this project?

In my mind "teaching physics" means two separate, but closely related things. First, it means teaching the rules that appear to govern the physical universe. It seems to be a fact that all the rich and beautiful and amazing behavior of our universe is governed at the most basic level by a collection of simple rules.

Knowing these rules has value on many levels. It helps engineers build things that work precisely and consistently (you can't get a man on the moon by guesswork, or even a GPS network in the sky). It helps you quickly assess the feasibility of political proposals (can we replace our power grid with solar arrays? Conservation of energy says "outlook poor"). And it seems to satisfy a deep human spiritual need to know. The Greeks couldn't build rockets, but they still wanted to understand the stars.

How much math? So much math.

Second, "teaching physics" means teaching how to think like a physicist. Every field of study has its own ways of thinking. Physicists think about things differently from engineers, and both think differently than historians, and also music teachers, and so on. These different ways of thinking have been carefully cultivated over millennia of human thought to solve the particular problems their respective fields.

For example, historians try to extract what truth they can from extremely limited information while avoiding bias and assumption. Physicists try to find simple, consistent explanations for the all manner of seemingly unrelated phenomena. And to accomplish this, we have developed tricks and techniques to help us, very few of which come naturally. We use math, we devise simplified models, we do experiments, and thought experiments, et cetera and so on. Every physicist carries a "toolbox for his or her brain", and the more tools you have in your toolbox the more you can accomplish in every part of life. If you're skeptical that thinking like a physicist is useful, just remember that "physicist" is basically a by-word for "smart."

Take that, humanities!

That all sounds great, but I need a strategy, and specific goals.

 The gritty details

The Rules of the Universe

First, I want a list of concepts I would like my mom (and everyone) to understand about our universe.

1. Everything is made up of particles whose motion is governed by simple laws.
2. Motion is relative (Newton's first law).
3. Motion is determined by forces, and momentum is conserved (Newton's second and third laws). 
4. Energy is conserved (and everything is energy!)

To me, these are the fundamentals. Pretty much every other interesting thing that happens in our universe is a manifestation of these laws. (Unfortunately they're not all true! (1) breaks down at the quantum level, or even in classical electromagnetism, and (3) and (4) aren't strictly true in general relativity, at least without a more advanced framework)

From these basic concepts, we can add on the principle behind various interesting phenomena. Gravity is a great subject for learning to understand forces and acceleration, so I'll probably include that. I have the luxury of asking Mom what she would like to understand and going from there. We will almost certainly spend quite a bit of time investigating acoustics because we both love sound and music. I'll decide on learning goals

Every goal needs a metric, and unfortunately it can be tricky to determine whether or not someone has actually learned a concept. Thankfully, there are plenty of other experienced physics teachers who have worked on this problem and created standardized assessments. They are designed to probe common misconceptions and concept-level understanding. I would like to use them, at least in part, partly because it saves me the work of designing my own, and partly for my own personal learning (translation: I am a huge nerd and enjoy reading academic papers on physics teaching). For some topics, like acoustics, I might have to design my own assessments, but I will deal with this problem as I come to it.

Thinking Like a Physicist

Things get a little more abstract here, so it's especially important to have concrete goals. I'm going to focus on specific tasks that I would like Mom to be able to accomplish. To start with:

1. Given a simple phenomenon, devise a mathematical model to describe the phenomenon, including picking relevant quantities.
2. Make plots to help discover relationships between physical quantities.
3. Use a mathematical model to predict the results of some situation, including identifying relevant formulae and using algebra to isolate variables of interest.
4. Design and perform an experiment to distinguish between competing hypotheses.
5. Given a phenomenon, devise an explanatory hypothesis and devise a way to falsify or confirm it.

These learning goals are perhaps easier to assess because they focus on producing a concrete result -- a plot, a successful experiment, a solved equation.

My hope is to teach these skills in conjunction with the physical laws. This should happen relatively naturally; after all, these are the things physicists of old did to discover the laws we know today.

I will be taking care that my lesson plans always work towards a learning goal from both bins, and when I post a lesson plan I will try to identify explicitly which points I am addressing. There might be a few lessons where this is not possible, but it's a personal goal anyway

Homework

I fully intend to assign homework. Just as you cannot learn to play the piano without actually playing the piano, you cannot learn to think like a physicist without thinking like a physicist. I suspect that you can't get a good understanding of physical law without practice either -- physical law is not intuitive, and it takes practice to retrain the brain to have new intuition. Nature doesn't seem to change itself to fit the way we prefer to think, so we've got to do it the other way around. 

I will try to make sure that every lesson has a few exercises at the end. We can go over the answers at the beginning of the next lesson.

 Experiments

I would like for this project to be experiment-heavy.  This isn't always easy, because really good experiments require really good equipment, sometimes custom made. However, the point of doing experiments is not to simply go through steps. My focus is on designing good experiments, identifying what makes an experiment able to distinguish clearly between hypotheses, and what makes good experiments difficult. Hopefully we will be able to build a few of our own. But sometimes we may design an experiment and then find a video of someone else performing a similar one, or I may just reveal what the results would be if we did it for real.

 In summary

From here on my posts here will be a mix of my lesson plans and descriptions of our lessons. I have not yet decided on the exact format of the posts, but I will try to make it so the reader can enjoy our antics but also learn a little physics at the same time. The homework exercises will be included, and I encourage anyone reading this to give them a try!

Next post: The first lesson -- Position, Velocity, and Acceleration or The Physics Simulator