Tuesday Teaching Topic: First Law of Motion Edition

Apologies for the lack of posts. I was lured away by the lovely weather and my Tuesday morning writing sessions converted into Tuesday morning lakeshore run sessions. Luckily for you, I injured my back, and am back with another TTT.

TTT Question: If a student receives an “A,” does that demonstrate that they understand the course material? Have you ever had an experience when an “A” student says or writes somethings that belies a fundamental misunderstanding

As the semester comes to an end, we look for evidence that our students have learned something. Tests, oral examinations, term papers, capstone projects, and final conversations can invigorate or devastate us, frequently cycling through both emotions throughout a single day.

I am always concerned about the sort of learning–or lack of learning–that flies under my radar. My students perform better on the tests, and write better papers, but has their deeper understanding of the subject improved, or have they merely learned to imitate knowledge? Let’s look at some relevant physics.

First Law of Motion: 

I read a frightening story once that stays with me constantly in the classroom (What the Best College Teachers Do, pg. 22-23, by Ken Bain). After a full term of mastering the fundamental laws of physics with some of the brightest and most devoted students, some professors found that most students demonstrated that their underlying notion of physics was still Aristotlean, not Newtonian. In other words, even though most students could perform exceptionally well on a difficult physics examination, their method of answering some questions belied that this was only a surface level understanding, and that they still operated as though stasis was the natural state of objects. Only some specially designed questions demonstrated their ancient paradigm.

“Ibrahim Abou Hallous and David Hestenes (two physicists at Arizona State University) devised and validated an examination to determine how students understand motion….Even many “A” students continued to think like Aristotle rather than like Newton [at the end of a course designed to teach Newtonian motion]…Halloun and Hestenes wanted to probe this disturbing results a little further…What they heard astonished them: many of the students still refused to give up their mistaken ideas about motion. Instead, they argued that the experiment they had just witnessed did not exactly apply to the law of motion in question; it was a special case, or it didn’t quite fit the mistaken theory or law that they held as true. ‘As a rule,’ Halloun and Hestenes wrote, ‘students held firm to mistaken beliefs even when confronted with phenomena that contradicted those beliefs.’…’They tended at first not to question their own beliefs, but to argue that the observed instance was governed by some other law or principle and the principle they were using applied to a slightly different case.’ The students performed all kinds of mental gymnastics to avoid confronting and revising the fundamental underlying principles that guided their understanding of the physical universe.”

Chilling.

I believe every discipline has some important lessons for all of us, and I appreciate physics for its ability to show definitively when our understanding of the world is just plain wrong or misconstrued in relatively clear and discrete terms. This is an example from physics, but it seems quite likely that something similar is going on in my own classes. And in philosophy, we don’t have the clear and relatively final answers that physics has to identify when this happens. So instead, I need to look at how physics deals with this, and see if I can apply the same methods in my own class.

I first watched the movie “Infinity,” a biopic about the physicist Richard Feynman, more than ten years ago. Overall, I found the movie mediocre, but it had a few enlightening moments. In particular, the four minute opening sequence is something that I find so poignant on the difference between trivial and genuine knowledge that I show it to all my students at least once per semester.

There are a few interesting pieces packed in this short clip. An anecdote about a bird comes at 1:24, when the 6-year old Richard listens to a bird, and asks his father, “What bird is that?” His father replies, “That’s a marvelous bird.” Trivially inquisitive Dick responds, “But what’s its name?”

Then comes the money line:

“Richie, I could tell you its name if I knew it, in all the languages in the world. But then you’d just know what people call it in different places. You wouldn’t learn anything about it. You got to look at the bird. You got to listen to the bird. You got to try to understand what it’s doing. You got to notice everything.”