1D Coarsening · Interface Density ~ 1/√t · Consensus Time
t=0 | interfaces=0 | ρ=0
Each site i copies opinion of random neighbor at rate 1.
Interface density ρ(t) ~ 1/√(πt) for 1D. Consensus time scales as T ~ N².
Coarsening visible as domains grow and merge — exact solution via duality with random walks.