Saturday, May 2, 2020

Alain Aspect's Quantum Optics on Coursera

I finally got done with finals, and as a reward, I decided to see if I could find a Coursera course to play with. I had been looking to see if there was a quantum computing MOOC available (and there are many), but among the search results was Alain Aspect's Quantum Optics course on Coursera. This is, he says, the first of two MOOCs based on his textbook (at right*). It's a short course (4 weeks, basically four lectures), and so, just right for me.

The subject is interesting (and very similar to a special topics course I took as an undergraduate called "The Quantum Mechanics of the Laser" -- I wish I'd kept those notes when I moved), but the lectures are dense. They do go over a lot of the material in Sakurai's Modern Quantum Mechanics*, which I worked through two summers ago, but of course with a focus on the meaning in terms of quantum optics. Already, some things I haven't heard of before, some that relate to experimental design (quantization volume), some straightforward interpretations of mathematical expressions (the energy of a single photon). The understand in terms of experimental parameters is particularly helpful to me (since I understand things in terms of experiments, due to my training).

The course, however, is not for those who are afraid of mathematics. Aspect's discussion in mathematically dense. Really dense. My students think I use too much mathematics in university physics classes, but this is all math. And Aspect expects you to have seen it all before: many times he references your prior knowledge. He doesn't quite say that you're an uneducated ignoramus if you can't recall trivialities like the photon energy or the uncertainty relations (he calls them dispersion relations, an aspect of his philosophy -- it's nice to hear an expert talk explain the mechanics of physics in a way that makes it clear he has opinions). And the homework is tough. Not as tough as it sounds when you read it, but pretty tough.[1] Even on the internet, you're expected to know your stuff.

I have found that I had to speed his lectures up. I don't know if it's him, if it's because he's European, or because Coursera makes everyone speak like someone shilling their latest book in a bad TED talk, but he talks slowly. Last summer, I took Werner Krauth's MOOC,[2] from the same school but a different country, and he spoke with the same cadence. I found I had to speed up the lecture to 1.5x so that they spoke at a normal speed.

This minor technical problem aside, I certainly am enjoying the break this provides before I start preparing for my summer courses (How did I let myself get roped into summer courses? At least they're on-line so I can get a lot of the work out early).

[1] I didn't pay the $49.99, or whatever, it costs in order to get it graded, but I did work it. And it reinforced the advice I give to my students: try the homework before class, then the class will be more useful to you. [2] Which was serendipitous, since I'd begun setting up to work through the book it was based on, Statistical Mechanics: Algorithms and Computation,* when Coursera sent me an e-mail about it. I get the feeling there's as much shilling on Coursera as there is at TED talks. But it couldn't be more: a TED talk is just an advertisement for a book. If you're lucky, there's more to the book than just the TED talk. Obviously, though, there's more to a physics textbook than eight hours of lecture. Hell, there's more to a physics textbook than the forty hours of lecture in a semester.

* Note: These links are to Amazon pages. Purchases on those pages from the links will give me a commission (at least for now -- every time I've tried to use the Amazon Associates program they've kicked me off for not selling anything, but I do like having the links in the show notes so that you can pick up the books we might reference in a discussion).