Beautiful Physics: A Summer Mini-Course

ESU, the Enrichment Studies Unit, is a really neat program here at Queen's. Instructors (usually grad students) can submit a proposal to teach a mini enrichment course on pretty much any topic they are passionate about. A diverse range of proposals are chosen, and the instructors set out to design engaging curriculum on their favourite topics. I think it's an ideal way to run these courses - giving autonomy to instructors to teach what they love.

So naturally, I wrote a course on... the history of penguins. I'm kidding, of 'course'.  My course was called "Beautiful Physics: Light and Sound".  I took a very different approach to the teaching style I used this past year in tutorials.  My whiteboards only came out twice - first for a boggle-style competition brainstorming all the different types of waves we knew, and later for a pictionary review game - we didn't do any problem solving because the students' math skills were too much of a barrier.

Instead, I went for a purely conceptual course with the goal of inspiring questions and finding a couple answers. One thing that I found interesting and encouraging: even without math, the course remained challenging for the students - this was important to me since it was an enrichment course for keen students. (Though a custodian saw the play-doh we used for stop motion, and refused to believe that I wasn't teaching kindergarten students - I was mildly taken aback. I still like play-doh... )

So we did a waves a hundred ways. The human longitudinal wave was a fun one, since it involved knocking over your friends. Similarly, the refracted human wave - lines of students walking quickly on pavement (representing light in air) and slowing down when their feet touched grass (representing glass) worked well for creating an experience of refraction.

We applied refraction to water waves, asking non-intuitive questions like:

As you can probably tell, the "lectures" were mostly done using Peer Instruction. It's easy to do and is the most popularly adopted strategy coming out of physics education research. So at this point - as a 'reader' in my class, you get to pull out your A B C D flashcard and vote for the most likely explanation you can think of for why water waves always move towards the shore. Then, find a friend, discuss the question with them, and then return to reading.

Wait - did you really discuss with a friend? Hmm, I think you should share the best explanation you can come up with - and see if you can tie it to refraction - in the comments. Next week, I'll tell you the rest of the story ;)

We went on to learn about refraction of different frequencies, chromatic aberration, and of course the question:

We looked at dispersion of both light and sound. We did sound dispersion with one of my favourite simple demos - try hitting the end of a metal slinky while holding the other end up to your ear. It's Star Wars! Not kidding! Buy a metal slinky right now and try it. Yes, right now. What happens is this: a clap or tap is made of a thousand different frequencies (or pitches) - high ones, medium ones, low ones, etc. But high frequencies travel faster in metal than low frequencies, so the high ones make it down the slinky and to your ear first... then the medium ones... then the low ones. So you hear Star Wars!

The other place we looked at dispersion was in optical fibers. We learned that in multimode fibers, light that bounces around (by total internal reflection) a lot in the fiber has to travel further to get from Kingston to Columbus than light that goes basically down the middle of the fiber without too much bouncing. The light that travels further takes longer to arrive; therefore the pulse smears out in time:

That's a real problem because then the skype conversation can't be interpretted by the computer in Columbus, and the conversation would fail! So what would you do to fix the dispersion problem in optical fibers?

Once again, discuss, drop me a question or two, and let me know what you think would work to reduce pulse dispersion in the comments! I'll explain the solution next week :)

So as you can tell, we did a lot of waves. Here's a sense of the topics we covered and questions we asked. If you're teaching anything related to these areas, feel free to drop me a note and we can share lesson plans!

• Moire patterns  - why should you not to wear a striped shirt on TV?
• Thin film interference - why do you see rainbows on puddles of gasoline?
• Doppler effect - how do we know that the universe is expanding, and why does the pitch of a motorcycle engine changes as it drives past you?
• Reflection - why do you look upsidedown in a spoon?
• Virtual images - how to make pigs fly (or look like they are)
• Total internal reflection - how does data travel to talk to a fabulous Jeremy via skype, or how do you trap a laser beam in a bending stream of water?
• Polarization - how do 3D movies work?
• Resonance - what do the Tacoma bridge (see this clip: http://www.youtube.com/watch?v=3mclp9QmCGs), a flute,  a swing,  a guitar, a singing bowl,  and a washing machine have in common?
• Overtones - how do you force nodes on a guitar string?
• Quantum, Relativity and other fun topics that students requested we learn about

Whew! That explains why I slept for 12 hours on Thursday night! So as you can guess, I was worried they would forget everything as soon as they'd learned it. I decided that I wanted the students to at least remember one thing, and gain a general sense that physics is the coolest subject ever. So the students made stop motion movies in groups to teach one concept to their friends. 

This group made a video about how a rainbow is formed. I was pretty impressed with the quality of the physics they explained in their video! http://www.youtube.com/watch?v=OR0SOlJ_9d0. Other groups had more trouble explaining the physics, but did have a lot of fun making their video - which was half of the goal. This group went for a Harry Potter style Schrodinger's cat video. http://www.youtube.com/watch?v=f1VBMc_8kkI&feature=youtu.be. And this group did a creative mix of a Schrodinger's cat and the Doppler Effect to tell a story of resuscitating the poor cat after he was observed to be in the 'dead' state. http://www.youtube.com/watch?v=8H-Qa5cbLXM&feature=youtu.be. It was a bit of a tricky call for me to decide if their choice of music for the credits fit the requirements of PG only. I decided this was a battle I wouldn't pick.

There were other battles I did pick. We had some sad issues with emotional and verbal bullying in the class. But I decided to take a different approach than the traditional scary "stop the bullying" approach because I know they've all heard that talk before.... and the bullying obviously hasn't stopped. So I chatted with the class about my experiences with bullying. The fact that empathy and interpersonal skills end up being way more important than putting people down to get ahead. That it's actually a good thing to be a bit quirky and have a personality that stands out when you're looking for a job. That it means a lot to have learned that you can persevere even when life is tough.  I think it helped that by the time we had the chat on bullying, they (including the bullies) liked me enough as a teacher, and were quite surprised to hear I was just like the kids who they were excluding and calling names.  

One of my goals in teaching the course was to show my students that physics goes way beyond our stereotypes as a subject that's simply about trains, airplanes and blowing things up.  It's a creative and beautiful subject that needs all kinds of people - men and women, introverts and extraverts, silly and serious, etc.  I hope the students took that message home. But I hope they took more than physics home. I hope they learned a bit about treating each other well too.

10 Strategies for Physics Teaching Assistants

My supervisor recently asked me to put together a "top ten" list of practical strategies for physics teaching assistants. Of course with only my first year of TAing under my belt, I am clearly not the most experienced person for the job, so I based this content in loads of physics education literature written by people far smarter than me.  I would also love feedback from you - friends who have taught physics, learned physics, or have simply experienced teaching or learning of any subject before. What resonates with your experiences? What sounds flowery and unrealistic? 


Teaching physics is not a trivial task. Even Richard Feynman, famous for his lectures, had a student remark,

"In advanced lecture courses, [Feynman] was inspiring, but... an hour later, you'd wonder what you learned.'' 

Every physicist, who wants to successfully inspire and communicate physics to the next generation, encounters challenges in teaching. Our elegant explanations are useless if our students can't construct their own understanding of the concept. But facilitating this kind of lasting learning is no easy task.

Fortunately, just as we've learned physics by practicing and studying physics, we can also learn to be great physics teachers by practicing and studying teaching. The following are ten strategies you can use as a successful physics teaching assistant. Some may seem obvious to you. That's great! Other things may surprise you - do question them! I encourage you to learn about the areas that surprise you, try strategies out in your teaching, measure the results, and discuss your experiences with your colleagues and with me.

1. Address prior knowledge

Students need to build knowledge into a hierarchical structure and organized mental framework. Your students have a whole host of ideas about the physical world, constructed through their experiences so far. If you simply tell the students new information without addressing their prior knowledge, they will fit your lesson into a perhaps incorrect framework, rather than adopting the framework you want them to learn.

• Don't merely ask a student, ``Did that make sense?'' Ask the student a conceptual question to make sure they understand. Borrow ConcepTests from Dr. Eric Mazur's Peer Instruction to get a few ideas of good conceptual questions.
• A misconception was likely developed through an experience in the physical world. So create a new experience to directly addresses the misconception. Set up the thought experiment or demo. Ask the student to predict what they expect will happen (and listen for how the student is thinking about the situation). Perform the experiment and observe what happens. Have the student explain ``why'', listening for understanding, not just right answers.
• Ask the professor of your course if you can administer a test of conceptual understanding such as the Force Concept Inventory. This will allow both you and the professor to obtain a sense of what your students know at the beginning of the semester.

2. Inspire intrinsic motivations

Your students do want to learn. Yes, even the life science majors who "have" to take physics. We all have intrinsic motivations to learn about our world - your challenge as a teacher is to inspire those motivations. Raise questions in your students. Don't just give them answers. Bring students onside so that they are not merely tolerant participants in your active classroom, but are actively engaged with physics.

• Have fun! Use problems on topics which make your students smile. (Perhaps an Angry Birds conservation of momentum problem)
• Tell students why you're asking them to do an activity. Appeal to their desire to learn. (eg. We're going to act out a circuit using ourselves as electrons and gummy bears as voltage because having a concrete image of current and voltage will help us remember and understand these ideas... and because we like gummy bears.)
• Use challenging problems which encourage students say, "Hmm, I wonder if..."
• Don't frequently remind the students, "This will be on the exam". This statement takes attention away from the students' internal desire to learn. Of course it will be on the exam - you don't need to remind them.

3. Care about marks

We've all made the frustrated complaint, "My students don't care about learning physics. All they want is a good mark". Of course our goal is to help all our students learn physics - and hopefully we've successfully inspired our students' intrinsic motivations to learn physics too. But they also care about marks for their medical school applications, for keeping scholarships, etc. And if something matters to a student, it matters to you - because your students matter to you.

• Make sure there exists a course outline ready for the students for the first day. You don't need to read this to your students during the precious tutorial time you have. But you do need to make sure that all students have access to it online or in hardcopy.
• Give students a rubric which details your expectations of the assignments or exam questions you will be marking. Stick to the rubric when you mark.
• You should rarely see surprised looks on students' faces when you return an assignment or test. This can be a check for you to determine the clarity of your rubric.
• If you get to decide how some marks are allocated, use marks to communicate what you want the students to value: Do you value conceptual understanding? Then be sure to have more than just quantitative problems on your assessments. Do you value innovative design? Then incorporate elements of design into the lab rather than doing purely cookbook labs.
• Don't speak dismissively when your students tell you their concerns with grades. Listen, empathize, and set clear expectations - marks are not given by you, but earned by the student.

4. Hold high expectations for your students

Lecturing sets the lowest expectations for students; it assumes that they can do no more than passively copy down the set of symbols you write on the board. We have top students here\textemdash expect these students to engage, think, and learn in your class\textemdash and structure your class accordingly. Your role is not merely to provide information; you empower your students to see that they have something worthwhile which they can contribute to the classroom. When you set high achievable expectations for your students' learning and help your students meet these expectations, your students' physics self-efficacy (students' confidence in their ability to do physics) will improve. Self-efficacy is associated with both increased academic success and retention in a physics major.

• Tell your students that you want everyone to achieve an A. Or better yet, show them with the effort you put into teaching them. 
• Use engaging strategies such as Peer Instruction in your tutorial - create a classroom culture where students know they are expected to wrestle with new concepts in class.
• When a group gets stuck while working on a problem, don't jump in and simply provide the solution. Ask leading questions which give the students an 'in' to start working on the problem themselves.
• As TAs, we are rarely the best teachers in the room. Encourage students who have just made a breakthrough in understanding to teach their classmates.

5. Pay attention to how you talk about your students

Value and respect your students in your discussions with colleagues. As you speak optimistically about your students, you may find your own perspective changing - you'll notice more of the potential in your students. Also, you are an essential aspect of building a great teaching culture in our department. When you value your students in your conversations, your colleagues may see more value in their students as well.

• Talk about your students' learning more than you talk about yourself teaching. This will take the focus of your discussion with colleagues away from elegant derivations, and put the focus on how you can better help your students learn.
• Focus on the success stories. Share the excitement of a struggling student making a breakthough in understanding.
• When a student is driving you crazy, find at least one good thing to say about them rather than complaining about them to a colleague.

6. Prepare for class

It's no surprise: to teach well, you need to prepare both your content and creative strategies for communicating this content. Don't waste the students' time (and yours!) by floundering, providing vague explanations that serve no purpose except to cover up a lack of preparation, or directing the students along unhelpful paths.

• Solve all the tutorial problems yourself before teaching them - don't just read the solutions before class.
• Talk about the material you plan to teach with friends or family who aren't in physics. What kinds of questions come up? Practice answering these questions.
• Don't underestimate the ability of your own brain to forget. Sure, you may be teaching "easy first year physics material" but that doesn't mean that every concept (and especially methods for teaching every concept) is at the forefront of your mind right now. A good teacher continues to put effort into preparing for class and improving their teaching no matter how many years they've taught the course.
• When students ask a question that you don't know the answer to, don't give them a vague answer to hide the fact that you aren't sure. Be honest, and if possible, look up the answer after class or ask the student to do so and share what you learn with the students the following week.

7. Teach your students how to learn physics

The only people in your classroom who can do the learning are your students themselves. When we try to simply make our students download information from the blackboard, we miss the crucial question of how learning happens. Get students thinking about how they are learning and how they could learn more.

• When a student gets stuck on a problem, ask him or her "How are you approaching this problem so far?"
• Recognize the diversity of learning styles in your class. What works for one student might not work for the next student - this is the fun and challenge of teaching! Just as you use multiple teaching strategies to communicate information, encourage your students to try different ways of learning and studying until they find a technique that works for them.
• Model how you think about a problem, not just how you would set up or solve the problem. Remember that you're not trying to teach your students how to solve the "sliding block on ramp" problem - you're teaching your students how to think about physics so that they can solve new problems, eventually solving problems that we don't know the answer to.
• Encourage students to write a brief summary of what they learned at the end of each week - both concepts and skills.
• Ask your students to tell you what they're doing well (e.g., I'm starting to pause and lay out the concepts before diving into formulae at the start of a problem now) and what they need to work on (e.g., I give up too soon when I don't see a clear path to a solution). For efficiency, this could be coupled with obtaining feedback for your teaching - at the end of tutorial ask your students to write advice for your teaching on one side of the page and advice for their own learning on the other side.
• Have your students teach each other, but tell them that they can teach only the overall concepts they used in their solutions - they can't get stuck in the mathematical steps they followed.

8. Build positive relationships with your students

Good communication in teaching is not just about delivering good content. Building a positive rapport and relationship with your students genuinely improves their motivation to learn in your class, and results in greater academic success for your students. It also just makes teaching so much more fun.

• Make sure you are finished setting things up for your tutorial or lab 10 minutes early. Then spend the 10 minutes before class just chatting one-on-one with the students who are early.
• Smile to your students.
• Use your sense of humour in class (of course being mindful to respect the diversity of the students in your class).
• Learn and use your students' names. To make this easier, ask for a copy of the students' names and faces. The professor of the course probably has a page of names and faces that you can photocopy and post at your desk.
• Use your personal hobbies. For example, if you like baking, consider bringing a snack for your students on occasion. Or if you have a keen class, ask the students to sign up to bring food to tutorial. 
• Find out what hobbies your students participate in. Then slightly change the tutorial problems so that your students are the star of a problem. (e.g., Instead of "a car accelerates..." change the problem to say "Jason accelerates on his skateboard...")

9. Create an environment that makes learning happen

You may not have access to expensive teaching technologies in your classroom, but fortunately, engaging teaching is a much more important factor in improving student learning than having a fancy classroom. You can make the environment you're given a successful teaching space. Also, classroom environment is not only created through physical items in the classroom. The way you communicate with the students is the most significant aspect of creating a positive environment.

• If you have a poor classroom and if it's a warm sunny day, bring your class down to the lake and teach in the friendlier environment of the outdoors, if this fits with the activities you have planned.
• Buy white boards (approximately 20$ for a sheet which can be cut into eight 2ft x 2ft white boards) for the students to work on problems in groups. This is particularly helpful if you hope to take some classes outside or if you lack desks in your classroom.
• Create an environment where students feel safe making mistakes. When a student gets confused while solving a problem, say "Let's go back to what you know". Don't pretend that they're doing fine, but don't emphasize their mistake either. Bring them back to a point in the problem where they feel comfortable, and ask leading questions (that they do know the answers to) to send them down the right track.

10. Obtain and use feedback continually

You may have heard the quote, "You haven't taught until they have learnt", which is attributed to John Wooden. Your students are a highly valuable resource to you. Continually check if your students have learned the material you thought you were teaching. Change your teaching accordingly.

• Give all your students a piece of paper at the start or end of your class. Ask them to tell you one concept that recently became clear (and how it became clear) as well as one concept that they would like you to cover again. Or ask them to tell you what helps them learn and what is hindering their learning in your tutorial.
• This takes courage, but it can be very helpful: Ask a professor or fellow TA to observe one of your classes and give you feedback. Often an observer at the back of the room can identify whether or not students are engaging with the material better than you can.
• Class discussion can be useful for checking students' understanding only in tiny classes (ten students or fewer). In medium to large classes, use another strategy such as Peer Instruction to check for understanding. Class discussion in medium sized classes causes many students to disengage and listen passively.
• Attendance can be one mode of feedback from students. If the students feel that the time they spend in tutorial is useful for their learning, they will likely come to the tutorial. If they aren't learning in your tutorial, they will likely not attend (unless marks are attached to attendance).
• It is helpful to measure the effectiveness of your teaching with a standard instrument such as the Force Concept Inventory, which you can administer in your tutorial at the start and end of the term. Gains of 40% - 70% on the FCI will indicate that you're on par with interactive physics courses in North America.

Great TAs are always learning to become better TAs. Keep learning new strategies for teaching, trying them out, reflecting on the feedback you obtain, and improving your teaching. And of course teach me when you come across something that works well for your class. All the best!