Live experiments
Small, self-contained simulations — real numerical methods and physics, integrated frame-by-frame in your browser. Each one is interactive. Updated occasionally.
Wave Equation
The classical wave equation ∂²u/∂t² = c²∇²u integrated on a grid with a leapfrog scheme. Click or drag to drop a disturbance and watch it propagate, reflect off the walls, and interfere with itself.
Verlet Cloth
A grid of point masses joined by distance constraints, integrated with Verlet integration and relaxed over several constraint passes per frame. Drag to push the cloth around; drag hard and it tears.
N-Body Gravity
Point masses under mutual Newtonian gravity, integrated with a symplectic velocity-Verlet step so orbits stay stable instead of spiralling from numerical drift. Starts as a binary; click to fling in more bodies.
Double Pendulum
A fan of double pendulums released from almost-identical angles. They track together for a moment, then the tiniest difference explodes into completely different paths — deterministic chaos, drawn as crisp fading arcs. Click to release a fresh fan.
Boids
Hundreds of agents running Craig Reynolds' three rules — separation, alignment, cohesion — with nothing choreographing them. Coherent flocks, splits, and swirls emerge from local interactions alone. Move your cursor to herd them.
Lorenz Attractor
The Lorenz system — three coupled ODEs from atmospheric convection — integrated into its famous butterfly. The trajectory never repeats yet never escapes a bounded region: a strange attractor, traced as a luminous curve you can rotate.
Fourier Epicycles
Any closed path can be rebuilt as a sum of rotating circles — the discrete Fourier transform made visible. Each circle spins at its own frequency; chained tip-to-tip, the last tip retraces the original drawing. Click to switch shapes.