Terra Cognita

A map of everything worth learning.

From what a number is to what nobody has proven yet — every concept placed in a prerequisite graph, with an openly-licensed library anchored to the exact pages that teach it.

Most sites tell you to read a book. This one tells you which sixteen pages, and what you need to understand first.

The scale

Every concept and every resource carries a level, so “basics to hardest” is a visible axis rather than a vibe.

  1. L0 Curiosity No prerequisites. Explainable to anyone.
  2. L1 Foundational Secondary school.
  3. L2 Introductory First-year undergraduate.
  4. L3 Core Advanced undergraduate.
  5. L4 Advanced Graduate.
  6. L5 Frontier Active research. Open problems.

Subjects