With so many courses now available as podcasts, I’ve been catching up on subjects I missed earlier.

What’s great about podcasts isn’t just that they don’t cost any money, but that they don’t cost any time. All those intervals during the day when your ears and mind are otherwise idle—the oddly-shaped and otherwise unusable plots of time during commutes, exercise, or errands—can all coalesce into full-length lectures thanks to an iPod with a pause control.

It’s certainly not the full college experience. You can’t ask questions. But you can rewind and play back anything that’s hard to catch the first time.

(There have been classes available online for longer through other means, including MIT’s OpenCourseWare. But their focus on the text of lecture notes or on videos means that they require undivided attention. Often they use streaming formats that keep you tethered to an Internet connection, and the most common player, RealPlayer, still has inexplicably poor control over rewinding and fast-forwarding. Even rewinding a single second makes you wait several extra seconds for re-buffering. So watching the streaming videos isn’t nearly as convenient as podcasts, which download in the background in their entirety.)

After you subscribe in a program like iTunes, it will automatically download the latest lectures as they’re posted and also make them available when you sync with your MP3 player. (If you’re catching up with a previous semester, you can just click the Download buttons beside the next few lectures whenever you’re about to run out.)

Here are couple to start with.

History 7B: Introduction to the History of the United States, 1865-2005

Course web site • Podcast web site • •

These well-planned and engaging lectures on American history after the Civil War are perfectly suited to podcasts. Their focus on changes in cultural ideas ultimately sheds light on the origins of today’s politics. The class doesn’t rely on slides and is perfectly understandable without any prior background in the subject. (My own previous background was a high school AP History class covering the same period, of which I remember just enough to know that it barely scratched the surface.)

Bio 2110/2120: Anatomy & Physiology

Web site • •

This class weaves all over (but no more than a couple of other A & P courses I sampled, so it’s something about the subject). You could make a TV series out of it that explored the body in the same circuitous way that the Connections series explored history. (Strangely enough, History 7B itself, because it hangs its themes on an overall chronology, would probably come out more like a well-edited reality show.) Unlike Connections, the lecturer takes a deliberately slow pace to avoid complete bewilderment at the end. The rambling, conversational style makes for relaxed listening, and despite some digression and repetition, he covers a lot of ground while making sure you don’t get lost, even without any visuals.

Putting aside the minor issue of slow downloads due to the college’s severe bandwidth cap, there’s interesting information here for body owners everywhere, along with explanations for all kinds of body quirks you probably long ago stopped noticing you had. It does of course lack its own TV series, but it might make House marginally more comprehensible. And anyone who engineers complex systems can take inspiration from the amazing self-regulatory mechanisms behind it all.

Another one you might want to check out:

Chem 1A: Introduction to Chemistry

Course web site • Podcast web site • •

This chemistry class is definitely entertaining, even as review, with multiple-choice pop quizzes that you can play along with at home, and a Mythbusters-esque love of wrapping things up with a bang. It does require more concentration than some other classes. Much of it is understandable by podcast, though a few of the quiz questions aren’t repeated out loud, and to see them you need to watch the RealPlayer video. What I did was listen to them first by podcast, then played the videos for the tricky parts.

More classes:

• UC Berkeley Webcasts
• Academic Podcasts
• Free Science and Video Lectures Online
• Massive Resource List for All Autodidacts

(Tip: When checking out a new class, you can usually skip the first half hour, or even the first lecture. It tends to be full of generalities and and administrative information, and you can always come back to it later. The second lecture says a lot about the teaching style and whether the class works in purely audio form.)

The reporter’s sense of irony in this news article pushed it to #1 on Daypop:

Bush told his senior aides Tuesday that he “didn’t want to see any stories” quoting unnamed administration officials in the media anymore, and that if he did, there would be consequences, said a senior administration official who asked that his name not be used.