Previously on LessWrong:

• The Best Textbooks on Every Subject
• The Best Tacit Knowledge Videos on Every Subject

Having seen the popularity of those previous initiatives, I thought it would be valuable to have a similar collection of lecture series. Many universities have made some of their lectures freely available online, leaving a lot of options to choose from. Lectures also vary widely in their quality, and I've often found better alternatives to the lectures offered at my universities online. It would thus be great to have a catalogue of lectures that people have found particularly good.

While lectures are usually of secondary importance to textbooks and exercises when forming deep gears-level models of a field, good lectures are still highly useful for building intuition about a subject, and they're also helpful for those seeking a high-level overview of a field without the ambition to become an expert. The Feynman Lectures on Physics is a classic example of a lecture series that serves both purposes. If this post introduces people to a couple of lecture series that they find as good as or better than Feynman's lectures, I'd consider it a great success!

How to submit?

For the submissions, I'll adopt a format similar to the one used in Parker Conley's post on tacit knowledge videos:

Domain: Statistical Mechanics

Link: Statistical Mechanics (Spring 2013) by Susskind Lectures

Lecturer: Leonard Susskind

Why? Susskind is a legendary physicist who is also excellent at conveying physical intuition and presenting topics in a highly engaging way. These lectures on Statistical Mechanics are no exception. I'll note that there are a few nonstandard choices in his approach to teaching the subject, such as not mentioning the concepts of microstates and macrostates at all in the first few lectures. Nevertheless, I liked it a lot overall.

For whom? The lectures were given for an introductory course and predominantly focus on building the right intuitions. I'd thus recommend it for people who don't yet have first-year physics undergrad-level knowledge in statistical mechanics.

Here are the rules:

1. Post your entry in the comment section with the above format.
2. It would be preferable that the lectures are available at least in audio format, if not in video, but if the best lectures you've ever seen were given by an underappreciated professor at an obscure university in the 1950s and are consequently only available in text format, I'd still want to know of them. The lectures don't have to be from official university courses, but also shouldn't be short YouTube videos — for example, I wouldn't count PBS Space Time's Understanding the Holographic Universe playlist as a lecture series, but Steve Brunton's Engineering Math: Vector Calculus and Partial Differential Equations would be fine.
3. If you have watched multiple lecture series on a single topic and can describe in your comment why your favorite one was better than the others, that would be ideal, but I won't make it a requirement.

On my end, I promise to create a section below with your recommendations once a critical mass of them has been posted, and to keep editing the post afterwards as dictated by the volume of new recommendations. Please share your favorite lecture series below!