What is physics?

Earlier today, I tweeted the following:

It lead to a great conversation with some physics educators whose opinions I really value. However, some of the conversation, though useful, wasn’t getting at my, admittedly-poorly-articulated, point. I thought I’d use this post to try to flesh out my point further.

Before I really embraced the concept of being a physics educator, I was immersed in physics as a discipline. This was in both graduate school and as a post-doctoral researcher. I was doing cutting edge research, and really trying to wrap my brain around some very difficult ideas, split between theoretical and practical/engineering problems. Back then I went to conferences like crazy, and interacted with lots and lots of physicists. However, when I think back on it now, almost none of that work had to do with mechanics or kinematics.

Now that I’ve devoted my career to physics education, though not necessarily physics education research, I spend about 10% of my time thinking about and teaching mechanics, 75% of my time thinking about and teaching non-mechanics physics, and the rest doing weird projects with students. Note that I’m not considering other time spent on service issues here, which really takes up ~25% of my time.

As I’ve embraced using social media (this blog, twitter, Global Physics Department most notably), I’ve noticed that the time spent interacting with other people has taken a sharp turn towards mechanics/kinematics. I really value those conversations, and I feel that I learn a lot from them. This post is trying to wrap my brain about the implications of that sharp turn.

Why the change? I would say a lot of it has to do with the fact that I interact with a ton of high school teachers. Nearly all of the classes I teach cover material that’s never considered at the high school level, including AP courses. So when I interact with high school educators, we find that most of our common ground, from a concept perspective, is in mechanics. That’s not the whole story, though. A lot of the conversations I’m involved in also revolve around the Physics Education Research universe. This is a place that’s also nearly dominated by thoughts/ideas/solutions about how to teach mechanics.

Is this a problem? I don’t think so, but it’s clear to me that it’s been tickling my brain every once in a while. Here are some things that get me thinking in this direction:

  1. Solid research from PER about how to teach mechanics might not apply to advanced topics. One thing that really has me thinking about this is the notion of pre/mis/conceptions. These exist and are a powerful thing when working with students with mechanics. They seem to be much less powerful for advanced topics.
  2. Ask a random person what physics is and they’ll likely say something about mechanics (“carts on ramps”, “Newton’s laws”, etc). Ask a physicist and they’ll likely not mention mechanics (“A way to model natural phenomena”, “An approach to explain the universe”). My initial tweet about modeling above gets at this.
  3. I never used any of Newton’s laws during my graduate school research. I did ultrafast optics, and so maybe people would say that I spent more time with Maxwell.
  4. Books like “Matter and Interactions” and “Six Ideas that Shaped Physics” often face an uphill battle for adoption in departments that are more, shall we say, traditional.

I found I really was impressed with Frank and Kelly’s response to my tweets above:


They’re both saying that, at least for modeling, spending time on physics as both content (often mechanics in high school) and physics as process is important. I’m really excited to see how Frank’s experiment goes.

Ok, having read through this post, I still don’t feel I’m articulating my feelings about this quite right, but it’s gotten me further than I was. Please join the conversation either here or on twitter.

About Andy Rundquist

Professor of physics at Hamline University in St. Paul, MN
This entry was posted in physics, teaching. Bookmark the permalink.

17 Responses to What is physics?

  1. I have been moving away from so much emphasis on mechanics in the HS Physics that I teach. There are so many topics in Physics, we cannot discover them all in one year. So which ones are most important? The ones you can build things and test them out and adapt them? I tried to have students pick a topic to explore in a team. They did not choose anything, just left it to me to pick the projects (the easy way out).

    • Andy "SuperFly" Rundquist says:

      I often get asked what topics HS teachers should choose, when they have the chance to do so. My answer is usually that they should choose a smaller number of topics and do them deeply. In the context of this post, I would say that meta discussions during that deep learning would be quite useful.

  2. jerridkruse says:

    Interesting Post. I don’t have much to say, but would argue the PER & the more general science Ed research on which PER is based does hold for advanced topics. There may be some repeated anomalies though. 1) those taking advanced physics may either not have certain misconceptions or 2) those taking advanced physics are adept at quickly realizing the flaw in their misconceptions & accommodating new ideas therefore instructors do not observe the misconception phenomenon.

    At any rate, I think the second part of misconception research, particularly conceptual change theory, is valuable even when students do not have misconceptions. We still need to consider how to make the new ideas plausible, intelligible, & fruitful in the eyes of learners. While most successful curricula do a nice job attacking misconceptions, the do an even better job of helping students make sense of ideas/phenomena. This last part might just be more important as it can be part of creating dissatisfaction with the misconception.

    • Andy "SuperFly" Rundquist says:

      Certainly helping students to “make sense of ideas/phenomena” is going to occur at all levels. I sometimes feel, however, that because my students have no preconceptions about some material, I should be careful with PER advice that’s grounded in how to deal with misconceptions.

      • Timothy Couillard says:

        Andy, I think this is a great point. What it there is no preconception (mis- or otherwise)? Many topics (solid state electronics, electromagnetism, etc.) do not suffer from this since they are abstract in nature unlike the Newtonian world we all grow up it.

      • There’s a good portion of PER that treats misconceptions differently, making them out to be networks of contextually activated elements (“resources”), rather than full-fledged concrete beliefs. I use this perspective when I think about how we might teach upper-division material, helping students to access and use appropriate networks of ideas/skills, because it applies regardless of students possessing any preconceptions. I think this really fits well with the idea of physics being about model building.

      • Andy "SuperFly" Rundquist says:

        I really like that way of thinking about it, Adam. Certainly, whenever anyone learns something new, they have to tie it to things they already know. For mechanics, students often have a lot of experience with the relevant content, and we, as instructors, have to work to find ways to connect to that experience. When it’s a new concept, that might only have analogous relationships with the students’ experience, we have to work to make sure that any analogies are made clear (both the strengths and weaknesses of the analogies). I like the model-building approach for this, because we can try to get students to realize that to “know” something, is to have several concrete ways of talking about it in the abstract.

  3. Timothy Couillard says:

    This is the classic struggle for physics teachers isn’t? My state standards for physics advise we touch on many different topics. You’d have to rush through Mechanics (isn’t it easy by now?) to get to the nanotechnology and “modern” topics they want us to include. PER and approaches like Modeling push for a deeper dive into fewer topics. Do I dive right in with motion on the first day each year or do I spend a few weeks looking at physics in terms of the size and scale of the universe (Powers of Ten, anyone?), or the modern puzzles of Dark Matter, and Dark Energy? Do you start your course discussing NOVA’s Elegant Universe and/or Fabric of the Cosmos, or end with it? How much time to I invest in teaching technology, spreadsheets, probeware, VPython, etc. Part of me wants to move deliberately and teach the power of the approach and part of me chides myself for not having time to spend on some topics at all. And I always feel caught in the middle. I feel drawn more to the process skills side of things but I am also constantly unsettled by the things we do not cover. What is most important?

    • Andy "SuperFly" Rundquist says:

      Thanks, that really captures what I see so many HS physics teachers doing. At the college level, this happens to a lesser extent in courses that don’t act as pre-reqs for things, but in the typical physics major curriculum, we’ve got gobs of time to hit more things. Though even then, many of my students think that physics is the topics they’ve worked with, and not the methods they’ve applied.

      • Melissa says:

        I think Oregon State’s Paradigms in Physics approach is one way to emphasize to students that physics is about a few key concepts and models. The courses aren’t organized by topics, but by broader conceptual ideas that are relevant to many subfields. It would be interesting to interview graduates of the Paradigms curriculum and graduates from a traditional physics sequence to see how each set of students views the field of physics — methods versus topics.

  4. Andy "SuperFly" Rundquist says:

    Here’s 1 of 2 comments from Brian Frank (some weird commenting error was happening to him):

    Your last sentence makes me think, I should try to reflect back some things I hear, rather than respond with my thoughts. So I hear several implicit things in this post:

    (1) One is a concern about not just how we teach, but what we should teach, and at what levels. Does it make sense to emphasize so much kinematics/mechanics when most practicing physicists do not use it? Or is it that mechanics/kinematics is a generative place for students to actually practice what physicists do because it is a rich place to practice modelling phenomena. One where students have ideas (a good thing if you want to build and refine models), one where students have access to phenomena, and one where the mathematical tools are within students’ grasp. You are curious about the extent to which students, within an environment, see physics as a canon of particular knowledge or a process of developing such knowledge more generally. Does modeling perhaps do a better job than other curriculum and balancing the two?

    (2) Second, I hear a desire to have more interactions with people about upper-level content. Right now, you have a large and awesome network of physics educators to interact with, but much of the substance of those interactions is lop-sided toward just a small fraction of your teaching responsibilities and interests. How do I expand my network of people I interact with so they include more people who think about, talk about, and are concerned with upper-level physics?

    (3) Third, is a concern that physics education has made less progress with research, curriculum, and in providing instructional support for upper-level courses. You are curious if general findings from research on the intro stuff “applies” to upper-level stuff. You are curious if learning upper-level is wholly different than learning intro, or just different in the details. I think you are also concerned that the history of curriculum and research on mechanics/kinematics is perhaps a barrier to tinkering, research, and adaptations of more modern curriculum that focus away from introductory material, even in intro courses.

  5. Andy "SuperFly" Rundquist says:

    and here’s the second from Brian Frank:

    After reading through comments, I wrote this… its too long, I apologize. So, I think much of the research at upper-level suggests that students do have and develop “misconceptions” as they learn upper-level material, but also arrive with prior ideas that contribute to the development of those misconceptions. Research has documented very specific patterns of student misunderstandings with QM operators, measurement, eigenstates, electromagnetic fields, the photoelectric effect, entropy, conduction, so on and so on. Just as with intro, student difficulties are not random. Some of these difficulties are thought to be traced back to misconceptions at the introductory level that were left unresolved. Others represent common misunderstandings that emerge, almost necessarily as students prior knowledge interacts with new ideas, representations, experiments, etc. I’m not sure, but I think saying that students have no or little “preconceptions” for upper-level may be a misunderstanding about the nature of the knowledge we bring to learn new things, and how understanding (including misunderstanding) happens. Students may be learning material about phenomena with which they have no direct experience with, but they learn that material (its ideas, its representations, its language) through lens of what they do know, which in QM for examples include ideas about particles, waves, barriers, energy, movement, probability, reality, measurement, etc. Initially, some of the connections students form will be useful and productive, but other connections they form will represent specific difficulties that are hard to overcome, I think for very much the same reasons that they are difficult at the intro level. If anyone wants to see how students’ intuitive and prior knowledge interacts with upper-level content, I’d suggest sitting down with some students and asking them to talk about a potential barrier in QM, and what happens with a wave or wave packet. Lots of intuitive ideas about waves or particle “hitting” and “moving” through “barriers”, and “decaying” arise and get applied incorrectly. Then, ask students to make a connection between the abstract barrier and a real life situation, in which the barrier could be a model. I think you’ll be intrigued by what happens.

  6. Joss Ives says:

    Hi Andy,

    I think Brian has covered all points that I would have made and in a much more thoughtful way.

    For the most part I approach my first-year courses the same way I approach my upper-year courses. I use most of the same pedagogical techniques (clickers, whiteboards, pre-class assignments, group quizzes). Because I use pre-class assignments at all levels, students have had some contact with the material by the time they show up in class (so now have “misconceptions), and the classroom portion of building student understanding really looks the same to me at all levels. As Brian said, the research has documented specific patterns of student misunderstandings across a vast array of levels and topics. By the time we are really trying to wrestle with the concepts in class, my general techniques of trying to build on and improve student understanding have been equally useful in 1st-year mechanics as 3rd-year quantum.

    I have been slowly developing an interest in this idea of how students view physics and how that view changes over their careers as students and beyond. I have mostly been thinking about it in the context of majors and how research experience, Advanced Lab and the upper-year canon (EM, quantum, etc.) shape their perception of the discipline as well as how they fit into the discipline. But I had not really been thinking about how this all starts at the high school physics level or even earlier in their experiences with science as children.

  7. Mylène says:

    I know what you mean, Andy. As you probably know, my teaching breakdown includes 0% mechanics. I learn a ton from high school teachers who focus primarily on mechanics; it would be great if I was also learning a similar ton about the E&M topics that are my bread and butter, but I know of only a few blogs/resources that fit the bill. Here are a few of them.

    This article inspired good conversation in class: The Scientific Method is Wrong (Mark Guzdial kindly gave permission to reproduce).

    The most even-handed critique of modelling I’ve read is Dean Baird’s. Note that I am an outsider to modelling, yet have a healthy respect for it as well as for Hestenes, Hake, and the FCI. I don’t necessarily agree with all of Baird’s points — I just think they’re well formulated and worth discussing. (Sequel is here.)

    You’ve probably seen this already but the comments here between Brian, Joss, John, and Frank help me think about why even a modelling curriculum could still leave students with the feeling that physics is about “being right” instead of “doing right.”

    A few other resources that might be of use: Jason Buell on teaching argumentation through a “Claim-Evidence-Reasoning” process; Grace writing about sense-making as myth-making and Michael Doyle’s post on the same thing

    • Andy "SuperFly" Rundquist says:

      Thanks, there are really helpful. Glad to know there are other physics teachers out there who spend more time away from mechanics.

  8. Hi SuperFly,
    It isn’t Quantum Physics. Just because it is being used doesn’t make it right. And, there is a right answer.
    Physics will be understood by something else. A different approach to understanding how things work, tgftop.org.

  9. Pingback: Core physics curriculum | SuperFly Physics

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