Why Are Physics Classes Full of Old Stuff?

Chad does a nice job of addressing the issue raised in a Minute-Physics video. Frankly, I thought the video was uncharacteristically naive about this particular subject.

The fact that these courses are service courses first and foremost constrains what we can teach. And much as we might wish it were otherwise, the engineering and chemistry departments don’t particular want us to teach the cool modern stuff. They want us to teach old physics from 1865, because that serves as the foundation for some of their courses. We have to teach classical mechanics first because that’s what the departments that provide most of our students want us to teach.

And, of course, foundational for more physics, as well. It’s tough to talk about things like energy and momentum in advanced discussions if the students don’t know about energy and momentum. Can you discuss what a laser is and does at 8 O’clock on day one of an introductory physics class? It’d be fun to talk about how one might do that, but I’m not seeing how we get there. It’s almost like saying “let’s go read some neat books, because that’s fun, but let’s skip over all that boring vocabulary that we spend years developing”. Like most interesting books, quantum mechanics requires more than a third-grade level of reading ability.

The thing is, I see this same issue quite a bit on the science discussion board that hosts this blog — Science Forums (dot net). People show up wanting to discuss neat new things they’ve heard about, or even propose some new model of how things work, but have no clue about the basics — meaning they don’t understand what’s going on in the article, or why their proposal won’t work, and don’t get the objections people raise.