Newtonian Gravitation: Softened Plummer Potential prevents infinite divergence during close encounters:
1. Symplectic Velocity Verlet: Conserves phase-space volume and maintains long-term orbital energy stability without artificial decay.
2. Inelastic Coalescence: Merging bodies conserve linear momentum: p = m₁v₁ + m₂v₂ and volume: R = (r₁³ + r₂³)¹/³.
3. Conservation Laws: Tracks kinetic (E_k), potential (E_p), and angular momentum (L) in real time.