Metropolis Monte-Carlo · T in units of J/k

Ising order, melting at the critical point

A quarter-million spins each flip a coin against their four neighbours. Cool the sheet and one colour conquers — the lattice becomes a magnet. Warm it and the pattern boils into static. Hold it at T = 2.269 and the domains grow to every size at once: a phase transition made of nothing but thermal chance.