Concentric Ring Product Timeline Grid

2x2 grid, 16:9, popular products of 1870, 1920, 1980, 2026: I(0) = blank matte background. I(1) = final concentric radial flat-lay forming silhouette $ SHAPE. ∂I/∂t = Δ(I, $ THEME, $ SHAPE) with constraints: center-to-rim chronology, silhouette adherence, soft shadows. Integration: t=0.0–0.15: faint silhouette outline and concentric guide rings appear. t=0.15–0.4: innermost objects (oldest) fade in at the center, heavily worn. t=0.4–0.7: middle rings populate, wear decreases, shape begins to emerge. t=0.7–0.9: outermost objects (newest) fill the rim, finalizing the silhouette. t=0.9–1.0: soft shadows deepen, ring labels appear along a radial line, final polish. Output I(1) as an 8K concentric tree-ring masterwork.