Free Electron Gas in a Metal — Drude Model

Metals conduct because their outer electrons are not bound to any single atom — they form a shared "electron sea" that drifts under an applied field while constantly scattering off the vibrating lattice of ion cores. This simulator renders that mechanism directly: a cloud of electrons flies ballistically through a 3D ion lattice, scattering at a rate set by the material's mean free time τ and picking up a small bias in the field direction between collisions. Switch between copper, aluminum, silver and iron to change the electron density and scattering time, raise the field or the lattice temperature, and watch the drift velocity, current density and conductivity — computed directly from the Drude equations σ = ne²τ/m — respond in real time.