This is not an e-book, and it is not a collection of flashcards.
The lecturer here is the 3D scene. Text and formulas play a supporting role: their job is to tell you what a thing is called and how to compute it after you have already seen it. Reverse the order and the formulas are just symbols.
What a module looks like
Every module follows the same skeleton, so you can skip around safely:
- A one-line physical goal — which single picture this module is trying to install in your head.
- What you will see — set before you enter, so that you are not staring at the screen wondering where to look.
- The 3D scene — the main event. The control panel beside it is there to be used, not admired.
- What to look for — written under the scene, step by step: change this, watch that. This is the densest part of the site.
- Common wrong intuitions — the traps nearly everyone falls into once, flagged in advance.
- Think it through — questions without model answers. If you cannot answer them, go back and drag some sliders.
- Go deeper — links into the textbook for the full derivations and exercises.
Controls shared by every scene
The buttons at the top left of the canvas are preset views. They are not arbitrary angles: each one is the direction from which some particular quantity reads most clearly. When a picture stops making sense, cycle through the presets first — that usually fixes it.
Three more buttons sit at the top right:
- 📷 Screenshot — saves the current frame as a PNG you can paste into your notes.
- ⚙ Display settings — render quality, colour-blind-safe palette, high contrast, in-scene labels.
- ⛶ Full screen — strongly recommended on a phone.
About performance
Every scene watches its own frame rate. If it stays below 35 fps for two seconds, it drops one quality tier (fewer particles, coarser subdivision). You can also lock a tier by hand in the display settings — once locked, the automatic downgrade stops interfering.
On older hardware, just lock it to “Low”: the picture gets coarser, but not one number changes.
A workable pace
Do not binge the modules. The 3D scene in each one deserves ten minutes of dragging, rotating and trying to predict what happens next.
One schedule that works:
| Stage | Modules | Goal |
|---|---|---|
| Week 1 | 01 → 02 → 03 | Build the basic “wavefunction + probability” picture |
| Week 2 | 04 → 09 | Understand time evolution; separate stationary states from superpositions |
| Week 3 | 05 → 06 | Spin and orbitals: two kinds of angular momentum |
| Week 4 | 07 → 08 | Measurement and entanglement — the hardest and most interesting part |
| After | 10 → 14 | Whatever interests you |
At the end of each module there is a self-assessment. It lives only in your own browser (localStorage): no account, no upload, no leaderboard. Rate yourself honestly — its only purpose is to tell you, two weeks from now, which module to revisit.
One warning
The hard part of quantum mechanics has never been the mathematics. It is giving up intuitions that have never once failed you in the macroscopic world: trajectories, “things are somewhere”, “measuring is just looking”.
The modules ahead dismantle those one at a time. It is uncomfortable while it happens, and that is normal — the discomfort is the old picture being replaced.
When you are ready, start with module 01.