Three classic simulations from my undergraduate computational-physics coursework. I first wrote them in C with OpenGL around 2011 and have rebuilt them as interactive, self-contained web apps. Each is a small window onto how simple local rules give rise to emergent structure: fractals, magnetism and the melting of matter.
Random walkers stick together into a branching fractal. Measure its fractal dimension (~1.71) live.
Open simulation →A lattice of spins ordering into a magnet, then dissolving into noise above the critical temperature.
Open simulation →Lennard-Jones atoms you can heat until the crystal melts, then cool until the liquid re-freezes.
Open simulation →