Science is Utterly Wet

Posting has been (relatively) light this week because today was the first day of classes. I'm teaching introductory modern physics (relativity and quantum mechanics), a class that I've taught before, but I've been putting a significant amount of time into revising my lecture notes, to keep the class from getting stale.

This has led to a reduction in blogging because I've been preoccupied with educational matters. Happily, PZ Myers comes along with a post about education. It's one of those chain-letter sort of posts, starting with an op-ed by Olivia Judson with some unkind words about high school biology:

Biology was a subject that seemed as exciting as a clump of cotton wool. It was a dreary exercise in the memorization and regurgitation of apparently unconnected facts. Only later did I learn about evolution and how it transforms biology from that mass of cotton wool into a magnificent tapestry, a tapestry we can contemplate and begin to understand.

This was picked up by Tara Smith at Aetiology, who adds:

I think I've mentioned before that this my high school bio class was like this as well--lots of memorization, a good dose of anatomy, but no emphasis on evolution to tie it all together. In fact, I thought biology was boring before I took an intro course in college. I'm happy to admit I was totally wrong (something I don't do very often!).

Finally, PZ chimes in with:

I didn't think biology was boring, but I sure thought my biology class in high school was a waste of time. It was almost as bad as that mandatory health class taught by one of the coaches (who clearly hated being there) that was little more than a study hall with pamphlets. My biology teacher wasn't a bad guyâactually, he was likable and interesting as a personâbut the class content was a dogawful bore. My daughter says similar things about her biology course right now.

That has me wondering: how many of you have had similar experiences with the public school teaching of biology? Could this be where the US is going wrong, treating biology as a subject that is drained of life by a stamp-collecting approach to reciting facts and details?

I am not by any stretch a biologist (though I enjoyed high school biology, thanks to a very talented teacher). As a physics professor, though, I can tell you that this problem is not confined to biology: lots of people say the same thing about high school physics.

In the case of physics, the missing unifying concept is calculus. When you try to teach algebra-based physics, you inevitably lose a bunch of the natural connections that are obvious in a calulus-based class. If you know calculus, there's a seamless connection between the idea of constant acceleration and the equation

x(t)=xi + vit + 1/2 a t2

Without calculus to tie everything together, kinematics becomes a bunch of different equations that you just have to memorize.

I think the problem goes a little beyond just the question of mathematics, though. High school physics classes too often rely on "plug-and-chug" problems, where you're given the force and the mass and asked to find the acceleration. This is very far away from the reality of college physics (let alone grad school), where the game is less about plugging numbers into formulae than interpreting complex physical situation to determine how best to describe a given situation mathematically-- sometimes by using a standard formula, sometimes by generating a new and different equation.

I think there are two main results of this-- I'm sure of one, and I suspect there's a second. The effect that I know for sure exists is that we get a lot of students coming into college thinking they're good at physics when they don't have any idea what physics is about. What they're good at is memorization and the manipulation of set equations, and that's not physics.

You can spot those students in the intro classes, because they struggle mightily with dynamics problems-- all those damn frictionless blocks sliding on frictionless planes connected by massles ropes over frictionless pulleys. Again and again I get asked "What equation do we use for this?," and the answer is always the same: "F = ma." Those aren't problems that can be solved by rote memorization-- each problem is slightly different, and there's no finite set of equations that can cover all of them. What they require is knowledge of the essential concepts that let you break a complicated problem down into a few simple equations.

Many of those students did well in high school physics, but they tend not to go far with the subject in college. They end up in some other field (engineering, chemistry, and economics are the big winners-- make of that what you will).

The second effect, that I can't be sure is real, is that students who would be good physics majors get turned off of the subject in high school, because they're bored by plug-and-chug memorization. It's hard to tell if this actually happens, because obviously, we tend not to see those students, but I think there's a lesser version of this effect visible in our introductory classes-- freshman mechanics can be deadly dull, and I think we lose some potential physicists as a result. A lot of people who say "I hated physics when I took it" hated a bastard version of the subject, that doesn't bear much resemblance to what actual physicists do on a daily basis. It's easy to hate a subject when it's taught badly.

This extends beyond physics-- the Regents exam in Chemistry when I was in high school was a joke-- and there are some systematic reasons for it. It's hard to get people with a good science background to teach public school, but a chimpanzee can teach rote memorization. And plug-and-chug problems are readily adapted to standardized tests, while good conceptual questions are pretty hard to write.

The situation is improving-- as noted in a previous post, there are lots of groups actively researching physics education, and there's been a push to improve teaching at all levels with a variety of innovative techniques. There's a group of local high school physics teachers that have a couple of meetings a year on our campus, and they're dedicated people working to really get at the concepts, and go beyond simple memorization. But it's hard work, and more needs to be done.


More like this

Today was my first day teaching recitation for the summer session Physics 202, the algebra-based second half of intro physics. Physics 202 focuses mostly on electricity and magnetism, where the first course (Physics 201) was mostly classical mechanics. The summer semester is split into halves for…
Anybody who has taught introductory physics has noticed the tendency, particuarly among weaker students, to plug numbers into equations at the first opportunity, and spend the rest of the problem manipulating nine-digit decimal numbers (because, of course, you want to copy down all the digits the…
An anonymous donor cashes in a $30 donation to ask: Homework solutions from intro physics through grad school physics are available online, and while working through Jackson and Goldstein problems can be miserable without some guidance, the temptation is there to plagiarize. When you teach, do you…
I'm teaching our sophomore-level modern physics course this term, which goes by the title "Relativity, Quantum Mechanics, and Their Applications." The first mid-term was a couple of weeks ago, on Relativity (special, not general), and the second mid-term is tomorrow, on Quantum Mechanics, and then…