Why Quantum Is Hard to Visualise
Quantum mechanics defies intuition. The wave function isn't physical; it's a probability amplitude that collapses on measurement. Particles tunnel through classically forbidden barriers. Two particles can be entangled across arbitrary distances. None of this has a direct visual analogy.
The challenge for a simulation is to make these phenomena legible — to show the math in motion without lying about what it represents.
Most popular explanations reach for a metaphor — a coin that is both heads and tails, a cat that is both alive and dead — and those metaphors get the headline idea across but break down the moment you try to reason further with them. A coin does not have a continuous phase; a cat does not interfere with itself. Our approach instead is to draw the actual wave function, evolve it with the real time-dependent Schrödinger equation on a discretised grid, and let the strange behaviour emerge from the numbers rather than being asserted in prose. If a wave packet splits and recombines with a phase shift, you see the interference fringes appear on screen exactly because the underlying equation produced them — nothing is staged for effect.
That said, we are not aiming for research-grade accuracy. A real hydrogen atom orbital calculation, a real many-body entanglement simulation, or a real quantum computer's error model would be computationally out of reach for a browser tab and would not teach the core ideas any better. Every simulation in this category will be a simplified but honest model: enough physics to be true to the equations, simple enough to run at 60fps on a laptop.
What's Planned
- Double slit experiment — single photon interference pattern building up over time
- Quantum tunnelling — Gaussian wave packet hitting a potential barrier
- Hydrogen atom orbitals — 3D probability density ψ² surfaces
- Schrödinger's equation solver — finite difference time domain (FDTD) on a 2D grid
- Quantum harmonic oscillator — energy level transitions, wavefunctions
- Bloch sphere — qubit state visualisation for quantum computing intro
The target audience is someone who has heard the words "wave function" but never seen one — not someone working on a quantum computer. The goal is conceptual clarity, not computational accuracy.
Each simulation will ship with a short companion article that walks through the maths behind what you are watching — the Schrödinger equation for the tunnelling demo, the Born rule for the double slit pattern, the ladder operators for the harmonic oscillator's energy levels. The idea is that the visualisation earns your curiosity first, and the article is there when you want to go one level deeper into why the picture behaves the way it does.
We are building the category roughly in order of visual payoff first: the double slit experiment and quantum tunnelling should land within the next few releases, since both compress a genuinely strange idea into a single, immediately readable animation. Hydrogen orbitals and the Bloch sphere will follow once the 3D rendering pipeline for volumetric probability densities is ready, and the FDTD solver will likely arrive last since it needs the most careful numerical tuning to stay stable at interactive frame rates.
The Quantum category page is already live at /categories/quantum/. The first simulations will appear there when they're ready.