Ugh I did the asshole thing again

bartlebyshop:

bgaesop:

bartlebyshop:

When I make posts about how people are graduating and don’t know anything, I’m trying to blame bad pedagogy. It’s fucking incredible how bad most physics education is. University teaching is building on a rotten foundation of bad math education. People arrive at university with all kinds of mistaken ideas about how trigonometry and calculus work. It’s really incredible, too, because often if you sit down with a struggling student for a few hours and draw a lot of diagrams they can consistently understand whatever it was. No one ever explained it like that before but I’m actually quite bad at explanations.

Then you get to university physics “education” which is almost entirely the way it is because of inertia. A lot of the material is taught in a completely backwards order. You’re one of 30 people sitting in section with a disgruntled TA who literally had 5 hours of teaching instruction. It’s not surprising people don’t want to ask questions.

So if people read these posts and feel bad, it’s because I was being an asshole.

could you expound on the “taught in a completely backwards order” thing?

At a lot of places you learn very basic quantum in 2nd year, then classical and E+M in third and fourth year. The problem with this is two-fold:

1) Quantum is based on energy methods (Hamiltonians and Lagrangians) which were first developed for classical mechanics and are often most easily presented for the first time there. When I took QM in 2nd year we were told “This is a Hamiltonian. It’s … a thing. You’ll see where it comes from next year!” Inspiring and educational, no?

2) People have been told their whole lives that quantum mechanics is very surprising. Surprising in comparison to what? If you take classical and E+M, the two older fields which were the conventional wisdom in 1900, after quantum mechanics then you have no idea what you’re supposed to be surprised by. It’s thematically unsatisfying and students in this position often can’t tell you at all what’s different between classical and quantum mechanics. Let alone classical vs quantum E+M.

I mostly agree with you.  I remember way back when I was a college freshmen hearing other freshmen complain that we weren’t learning cool stuff like quantum mechanics, and thinking this was ridiculous because the same people were having a hard time grasping concepts like angular momentum.  Even at the time I knew that QM would make a lot more sense in the context of a solid understanding of classical mechanics.

But on the other hand, some of the same people who acted like this went on to do really well in physics, so maybe in some way they were right all along?  Teaching QM early is just pandering to people who want to “learn cool stuff,” but then the people who end up becoming the most motivated physicists are often the ones who are the most into “learning cool stuff” (conditioned on actually being able to do math and so forth).  Maybe these people should learn to be less superficial or less easily bored but when they are not bored they can work pretty amazingly hard.

(via bartlebyshop)