p>Gordon Watts has some thoughts on a subject near to my heart: the ways we drive students out of physics.
For the past 6 years I've taught various versions of the introductory physics survey course. It covers 100's years of physics in one year. We rarely spend more than a lecture on a single topic; there is little time for fun. And if we want to make room for something like that we usually have to squeeze out some other topic. Whoosh!
It gets worse. At the UW we are lucky enough to have a large contingent of students from excellent high schools. This means they have seen almost all of the material previously! Snore!
Amen, brother. I've come to the same conclusion, particularly regarding the students with good high-school physics backgrounds. Our introductory mechanics class is particularly rough on them, because the first six weeks or so look exactly like high-school physics, and students who have seen the material before start to tune out-- they stop doing the homework, they stop taking notes, they stop coming to class. And then, when we hit them with some material that's new to them (Special Relativity and vector angular momentum), they've developed all these bad habits, and just get crushed. And they get stomped on even worse in E & M the next term, which starts off with new-to-them material.
(More after the cut.)
I try to do what I can to keep them working, through a homework policy that is byzantine in its complexity, and by giving a whole bunch of short quizzes to make them focus on the class work, but it only helps a little. And the most frustrating thing about the whole deal is that it selectively affects the best students-- the ones who have the preparation to be able to handle something more interesting, if we could hold their attention.
As a department, we've tried to deal with this by splitting most of those students off into an Honors section of the intro classes, where they get some extra material. And, like Gordon, we're starting to experiment with a radically different curriculum for the intro classes. Gordon talks about using the Six Ideas That Shaped Physics series, while this past year, our chairman used the Matter and Interactions course. They're very different approaches-- Six Ideas starts with conservation laws, and organizes the class around core principles of physics, while Matter and Interactions makes heavy use of computer simulations to tackle more realistic problems than the standard curriculum allows-- but they have one important common factor: they look nothing at all like high school physics.
I haven't taught under either of these curricula, though I have cribbed a good deal of material from the Six Ideas books for various classes. I'd certainly be willing to give either of them a shot. There are some concerns, though, about how they work for students who don't have a good background in physics already, particularly with Matter and Interactions, which adds the complicating factor of computers (given the number of students I see who are freaked out by Excel, VPython may be a bit much to ask). It's a Hard Problem, in the end.
(The post title, by the way, is a joke that only a very small number of people will get-- it's something that was said by a visiting seminar speaker at NIST, in response to a question from Bill Phillips, who won a Nobel Prize six months later...)
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I haven't taught intro physics in a long time-- all the intro stuff I teach is non-majors astronomy, which is a different target group and a different sort of class. However, back when I did it as a grad student at Caltech, I observed the same thing. Students would cruise through basic mechanics (though we managed to keep it pretty hard), but when we got to rotational motion and the SHO, the bodies were stacked like cordwood.
I'm struggling with the right way to teach introductory astronomy. The standard way-- "forty two topics driven by in forty two lectures"-- just doesn't do it for me. It becomes entirely a "memorize facts" class with a minimum of understanding required. Alas, that's what the students want and expect, as they've learned somewhere (probably high school) that memorizing facts is the way to do "well" in a science class. But it's just so boring, even of the facts are interesting, because we drive by so much stuff in so little depth. Right now I'm experimenting with the notion of focusing the whole class around the questions, "How old is the Universe? How do we know?" There are three main parts to the class. First, the age of the solar system, which gets into radioactive decay. Second, and longest, stellar evolution and the age of star clusters. Finally, the expansion of the Universe and the Big Bang. I tried it this summer, and can see a lot of tweaks that it still needs, but I'm going to keep trying to stick with this approach.
Of course, that means that there are no textbooks that work for this.... All the introductory astronomy textbooks are to first order the same, and are packed with way too much information about too many topics.
-Rob
I'm a high school student and I'll be taking AP Physics next year. I've already done two years of physics, and looking at the subject test I will have covered most of the topics I'll be doing next year. But personally, I fell in love with physics since looking at the stars. And I think for anybody to study a scientific area they need a sense of wonder, one that can't be taught. It's very hard to break pre-conceptions that people have when going into a physics class. That nature should conserve energy should be enough to make anyone wonder "why?". It's very amazing when you think about it enough, that nature would bend its self over backwards to conserve these things; that it would go out of its way to make sure nothing can go faster than light. I mean for god-sakes space and time them change! It's as if nature made these rules and then later twisted its self into this weird mess to make sure those rules would never be broken.
And the fact that all of this can be understood with math! All these things are enough to make anyone who can understand them be awed with wonder. Unfortunately, most people just can't seem to think along those terms. Everything becomes just an equation, just a math riddle and they lose sight of the fact that here on this piece of paper they are seeing a small part of the huge beauty that is nature.
Personally, we should make physics a little bit more awe-inspiring by incorporating it with a lot more subjects and making sure people get the idea of how interconnected everything is. Richard Feynman always said that the things we separate into Biology, Chemistry, and Physics are just human constructs, that in reality the divisions don't exist. If people were shown just how connected various topics are, and that what they are actually studying is the inner workings of nature, of god if you will, and not just "physics", I think it would help a lot. At least, that's what did it for me.
I tend to agree. I remember completely abandoning homework (but still going to the classes, hoping for interesting things to happen). Even the new one was trivial when you grasp the theory class. So during all the pre-graduation process I developed a lazyness towards exersices, and when, in the doctorate, I started to need these muscles, they were very weak; it is fortunate that computer support can be used nowadays.
Said that, there is another problem: if you put a lot of emphasis in exercise, you bias the selection of students and you get the current hep-th/ph status: a lot of people enjoing exercise, with only a few worrying about physics goals.
i agree with you, even from the other side of things.
i was a non-physics major who took a horrendously taught ap physics class in high school, and then a (well taught) standard physics class in college. the exercise was what i needed to understand, to get through. but i know that the physics majors in the class constantly moaned about how boring and slow everything. and yet...as the class progressed, i did better and better than they did.
on the other hand, i was a biochem major who had a solid chem background and so jumped into an advanced gen chem class which was much more focused on principles and thinking.
what you describe as a potential problem, tho, of physics majors not having much of a background--well, then they should just not be in the honors class. maybe they can jump in during the second year. (again, in my undergrad program there was an advanced gen chem and an advanced orgo. if you did well in 'regular' gen chem you could then jump into the advanced orgo class.) so i'm not sure how that would be a problem, persay.
As a student I taught a lot of fellow students (mostly future engineers) physics. In first year physics courses at Michigan Tech, students were allowed a formula sheet. The first thing that I typically did for my classmates was to get rid of the ridiculous formula sheets and provide them with the, perhaps ten, necessary formulas for the upcoming test.
I helped many C and D students get As and Bs. I watched many students go from desperately looking through the page of formulas to knowing which one was appropriate right away.
Learning how to do physics requires some one-on-one mentoring - which as good for the student AND the mentor.
My primary complaint about first year physics classes was the labs. I would hope that things have changed a bit - this is where the excitement SHOULD be - but I found every lab to be exceedingly tedious and uninteresting. Chemistry labs were more fun.
I have fond memories of my chemistry instructor reaching into a pot of boiling oil to grab something (heat transfer) and blowing up two balloons equally - connected by a valve - and asking what would happen when he opened the value. Everyone thought that the balloons would equalize - but that's not what happened when he opened the value - one balloon got big and the other got small (elasticity.)
I don't believe I went to more than 1/2 of the lectures in first year physics - and I was a physics major! I think the only test I didn't get an A on was the first test on Gaussian Surfaces in E&M (which I learned quite well while tutoring later.)
Stop worrying about the order that things are taught and worry about how goddamn BORING lecturing about problems is. Let's see some demonstrations - computer graphics - swinging pendulums - make the lectures as magic as my ol' chem teachers were (poor guy burned himself the third lecture of the day - the protective oils around his arm were gone by that lecture.)
Later in graduate school I had the pleasure of teaching labs on Calculus with Mathematica at MTU. Not all of the physics labs have to be physical.
Good luck.
The comments on intro physics classes do not mesh well with my experiance. The honors classes here were rather chalanging, even people who got 5's on the AP's said they were chalanging
so it can be done (we used klepner and klinko as out text book [i think i spelled their names wrong though]). They recently redid the way they taught the first semester, and non of the students who i heard about it from thought it was an imporvement.
I do agree that teaching someone something is one of the best ways to learn it really well.
Rob Knop mentions that students want and expect the "boring course", because "they've learned somewhere (probably high school) that memorizing facts is the way to do 'well' in a science class". I have encountered this in teaching computer science courses as well. And this is a problem that really does affect better students qualitatively differently, because they have mastered the old way of doing things! As a result, some of them will resent a new kind of course My experience, though, is that you just have to stick to your approach through some rough patches early; nearly all of these students
will eventually come around and appreciate the idea- and practice-driven approach even more once they adapt to the change. Remember, adaptation to change takes time, even for those eager to to change...
Unfortunately, most people just can't seem to think along those terms. Everything becomes just an equation, just a math riddle and they lose sight of the fact that here on this piece of paper they are seeing a small part of the huge beauty that is nature.
To be fair, this isn't restricted to the laity, or even to introductory students. It's really very easy to get caught up in calculational minutiae, and lose track of the larger physical picture.
Rob Knop mentions that students want and expect the "boring course", because "they've learned somewhere (probably high school) that memorizing facts is the way to do 'well' in a science class". I have encountered this in teaching computer science courses as well. And this is a problem that really does affect better students qualitatively differently, because they have mastered the old way of doing things! As a result, some of them will resent a new kind of course
Absolutely. And given the importance placed on student evaluations, particularly for junior faculty, this can be a huge obstacle to change.
My experience, though, is that you just have to stick to your approach through some rough patches early; nearly all of these students
will eventually come around and appreciate the idea- and practice-driven approach even more once they adapt to the change. Remember, adaptation to change takes time, even for those eager to to change...
The other thing that I've found to be very helpful is explaining what you're doing, and why. When I go through the extra steps I require for homework problems and the like, I make sure to explain (three or four times, actually) what the pedagogical purpose of this is. I think most students are willing to cut you some slack if you explain that there's a good reason for what you're asking them to do.