What are you learning?

This is a thread to connect rationalists who are learning the same thing, so they can cooperate.

The “learning” doesn’t necessarily mean “I am reading a textbook /​ learning an online course right now”. It can be something you are interested in long-term, and still want to learn more.

Rules:

Top-level comments contain only the topic to learn. (Plus one comment for “meta” debate.) Only one topic per comment, for easier search. Try to find a reasonable level of specificity: too narrow topic means less people; too wide topic means more people who actually are interested in something different than you are.

Use the second-level comments if you are learning that topic. (Or if you are going to learn it now, not merely in the far future.) Technically, “me too” is okay in this thread, but providing more info is probably more useful. For example: What are you focusing on? What learning materials you use? What is your goal?

Third- and deeper-level comments, that’s debate as usual.