anthropocene

A free, open-source, deeply interactive learning platform. Learn by doing — without the ceiling.

Brilliant proved that short interactive problems beat reading. It also charges a lot and stops well short of the material a practitioner actually needs. This keeps the interaction model and removes the ceiling: every topic runs from foundation to frontier on one page, and you choose the depth.

Live: https://entangledquantum.github.io/anthropocene/

What makes it different

• Predict → run → confront. You commit to an answer before the simulation runs. Watching your prediction fail is the mechanism; a paragraph cannot do it.
• Graded on behaviour, not on syntax. Code challenges measure the convergence order your implementation actually achieves. Any correct method passes. A plausible one that is secretly second-order does not.
• One concept, one owner. A concept is taught by exactly one lesson, enforced at build time. Everything else links to it — so the material never repeats itself, and the list of unwritten topics is generated rather than maintained.
• Foundation to frontier in one lesson. <Tier> blocks fold away the depth until you ask for it.
• Recall built in. Cards are authored inline where the idea appears and scheduled with FSRS-6.
• Yours, locally. XP, streaks and review state live in SQLite in your browser. No account, no server, no subscription, works offline.

Stack

Framework	Astro 7 + React islands — 0 JS on prose, hydration per widget
Math	KaTeX rendered at build time via Satteri's native math support
Plots	Canvas data layer + SVG axes on d3-scale / d3-shape
3D	three.js + @react-three/fiber, WebGPU where available
Storage	SQLite-WASM (opfs-sahpool VFS — no COOP/COEP, so it works on GitHub Pages)
Recall	ts-fsrs (FSRS-6)
Search	Pagefind — chunked index, downloads only what a query needs
Python	Pyodide, lazy, opt-in per lesson

Run it

npm install
npm run dev          # http://localhost:4321/anthropocene

npm run content:check   # concept-graph rules, gaps, per-lesson requirements
npm test                # asserts the physics: orders, stability, energy drift
npm run build           # runs content:check first

Adding content

Read AGENTS.md. It is the authoring contract — widget vocabulary, the never-re-teach rule, and the architectural constraints that will otherwise cost you an hour.

npm run new:lesson -- --path computational-physics --chapter 03-ode-solvers \
  --id 05-dormand-prince --title "Adaptive steps in practice" \
  --teaches embedded-pairs --requires rk4,butcher-tableau

If the path does not exist, it is created. Give it a category and it builds the learning path around it.

Content

content/ is fully separate from src/. Nothing in it imports app code and nothing in src/ hardcodes a lesson.

The first path is Computational Physics: floating point → finite differences → ODE solvers one at a time → structure-preserving integrators → spectral, variational, Monte Carlo and differentiable simulation.

Licence

MIT for the code. Content under CC BY-SA 4.0.