Soft spheres with harmonic repulsion V ∝ (1−r/σ)² jam at packing fraction φ_J ≈ 0.64 (3D random close packing). Near jamming, pressure P ∝ (φ−φ_J)^1 and the shear modulus G ∝ (φ−φ_J)^0.5 diverge with distinct exponents — a new universality class (O'Hern et al. 2003).