[Question] What are your favorite examples of distillation?

I’m a big fan of the Distill machine learning journal and the ideas of Research Debt and distillation. I consider Distill and LessWrong great repositories for distillations of ML /​ AI and some math topics. However, I’ve recently been hankering for distillations from other fields with which I’m somewhat familiar—biology, algorithms, economics—or even not that familiar. (John Wentworth’s recent series of posts on aging and constraints are good examples of one form posts like this could take.)

So, I figured I’d ask here: what are your favorite examples of distillation in different fields? I’m open to more ML /​ AI related posts but am especially excited about responses in the fields I mentioned above or other different fields (I would include math here too). Ideal answers would be posts that optimally trade off:

  • Describing a non-trivial topic.

  • Not “dumbing it down”.

  • Being accessible to non-experts.