Monte Carlo simulation of the 2D Ising model with adjustable temperature, showing the ordering transition at the exact critical point $T_c = 2/\ln(1+\sqrt{2})$ [ Try it online!](/demos/IsingModel2D.html)
An interactive simulation of continuum percolation: disks of a given radius are deposited at random positions in a square box, and the occupied area fraction is tracked as clusters grow and eventually span the system [ Try it online!](/demos/DisksPercolation.html)
Monte Carlo simulation of the 2D XY model: lattice spins coloured by orientation, with adjustable system size and temperature and a live energy-per-spin readout [ Try it online!](/demos/XYModel2D.html)
Continuum percolation of overlapping ellipses, with sliders for the major axis and aspect ratio and optional periodic boundary conditions [ Try it online!](/demos/EllipsesPercolation.html)
Continuum percolation in three dimensions: overlapping spheres are dropped at random into a cubic box while the occupied volume fraction is tracked. Rotate and zoom to inspect the clusters [ Try it online!](/demos/SpheresPercolation.html)