Distribution of phase-space distances in a cluster with 1024 particles. Units are dimensionless N-body units (Hénon 1971). The gray shaded region indicates the initial conditions in a virialized unit cube. One particle, indicated with the black bullet point, is displaced by 10⁻⁷ along the Cartesian x coordinate. The final conditions (at t = 10) of the unperturbed particles are represented with the bullet points. The color and size of the points represents the phase-space distance measured over the duration of the simulation (10 N-body time units), and ranges over about four orders of magnitude. The majority of objects experience considerable change in their orbits, but some are hardly perturbed. Calculations were performed using Brutus until convergence to 3 decimal places, which requires a tolerance of τ = 10⁻⁴⁰.