Directed Percolation — Non-Equilibrium Phase Transition

Probabilistic cellular automaton with absorbing state. Phase transition at critical p_c ≈ 0.6447.
Active cells (purple) → absorbing state (black) is irreversible.

Controls

Survival prob p: 0.65 Grid width: 160 Speed: 5 steps/frame

Step: 0

Density ρ: —

p_c ≈ 0.6447

Phase: —

1D contact process / DP.
Below p_c: absorbing state.
Above p_c: active phase.
β ≈ 0.2765 (DP universality).
ρ ~ (p−p_c)^β near critical.