The start-point for the thought experiment that is The Knowledge is a post-apocalyptic world where survivors must rebuild civilisation from scratch. But another way of setting that back-to-basics question is as a cheat sheet for a time traveler. If you were to go back 100, or 1,000, or 10,000 years, what crucial knowledge would you want to take with you to accelerate history as much as possible? What hints on science and technology would be relevant to different ages? This same idea is delivered very nicely in a design of time travelers’ essentials, which I believe first appeared as a t-shirt:
…and is also available as a high-res poster here. There are flaws in the execution. For example, the Wright brothers struggled with far more than just the shape of an aerofoil wing – building airframes and power sources light enough, and figuring out moveable surfaces to control the first aircraft are just as critical. And providing the chemical formula of an alternative to progesterone for birth-control pills as “C20H26O2“, without any hint of the actual molecular structure or how to synthesise it, is useless. But the idea of a time travelers’ cheat sheet is a great one.